A non-inflatable tire and its design method

Abstract

The present invention discloses a non-pneumatic tire and its design method. The tire successively includes a tread pattern, a tread, a V-shaped support structure, and a tire inner ring. The V-shaped support structure is formed by arranging V-shaped supports in sequence and connecting them end to end. Each V-shaped support consists of two upper sides, two lower sides, and a height. The upper side is connected to the tread, and the lower side is connected to the tire inner ring. Half of the supplementary angle of the included angle between the two lower sides is the inclination angle of the V-shaped support. The extension line of the height passes through the geometric center of the tire. In the non-pneumatic tire of the present invention, the cross-sectional area of the radial section is equal everywhere, so the radial material distribution of the tire is uniform. When different points of the tire touch the ground, the force conditions and displacement deformations of the tire are similar, so the sinking amounts are similar and the driving stability of the vehicle is relatively high. The design method of the present invention initially determines the tire width W, aspect ratio AR, and tire inner diameter D according to vehicle requirements, market tire specifications, etc., and then calculates in combination with strength requirements. The design method can be applied to tires for various purposes.

Description

Technical Field

[0001] The present invention belongs to the tire manufacturing technology, particularly to the structural design of non-pneumatic tires. Background Art

[0002] At present, most of the tires on the market are pneumatic tires. Pneumatic tires use the high pressure of compressed air inside the tire to carry the load of the vehicle and have good riding comfort. However, pneumatic tires are prone to safety accidents such as air leakage and blowout, which affect the driving safety of the vehicle. Especially in special industries such as military and mining applications, ordinary pneumatic tires may lose their performance due to being unable to withstand daily impacts, thus affecting normal work tasks. With the increasing emphasis on tire safety in the industry, traditional pneumatic rubber tires can no longer meet the new requirements of the industry. Non-pneumatic tires do not require air and only use the tire's own materials and structure to achieve support and buffering performance. Therefore, non-pneumatic tires do not have problems such as blowout and air leakage, greatly improving the driving safety of the vehicle.

[0003] Non-pneumatic plastic tires can be further divided into solid tires and non-pneumatic tires with a support structure. Solid tires are heavy in mass, poor in dynamic performance, and have poor heat dissipation at high speeds, and can only be used for low-speed load-carrying vehicles. Non-pneumatic tires with a support structure use the support structure to replace the compressed air in traditional tires for buffering, improving the heat dissipation performance and solving problems such as "hopping" of solid tires, and have good development prospects.

[0004] However, currently, traditional non-pneumatic tires with a support structure have a polygon effect. When the tire's contact points with the ground are different, there are significant differences in the amount of sinking. During vehicle driving, it is easy to generate bumps. For example, Patent CN110228325A mentions a non-pneumatic tire structure, which includes an inner ring connected to the wheel hub, an outer ring connected to the tread rubber, and an N-shaped elastic body connecting the inner and outer rings, jointly forming a ring-shaped non-pneumatic tire. It overcomes the inherent defects of the existing pneumatic tire structure and provides a tire structure that can run without inflation. Using the tire with this structure can avoid the occurrence of tire blowouts, greatly improving the safety of the tire. However, the non-pneumatic tire of this patent has a polygon effect. When the contact point is between two spokes, the amount of sinking is large, and when the contact point is at the spoke, the amount of sinking is small, which will lead to poor driving stability of the vehicle. Although the non-pneumatic tire with a continuous support structure has a stable amount of sinking, its support structure is difficult to form and process, and it is not lightweight enough. For example, Patent CN114329944A mentions a non-pneumatic tire with a continuous support structure. The continuous support structure can improve the stress distribution of the non-pneumatic tire, and the continuity of the force between the tread, the support structure, and the ground is improved, and the amount of sinking is stable. However, the forming process of the non-pneumatic tire of this patent is complex, and the tire weight is much higher than that of the same-size discrete support structure tire, which does not conform to the development trend of modern vehicle lightweight. In addition, the rotational wind resistance of the non-pneumatic tire is also crucial for vehicle performance. Currently, most of the products on the market are straight-hole support structures or non-hole support structures, and the wind resistance is large when the tire rotates, resulting in increased fuel consumption. Based on this, there is an urgent need in the field for a lightweight and environmentally friendly non-pneumatic tire with a stable amount of sinking and simple manufacturing and processing. Summary of the Invention

[0005] In view of the advantages and disadvantages of the above two non-pneumatic tires, the present invention proposes a non-pneumatic tire and its design method, which can make the tire meet both the requirements of stable sinking and lightweight requirements, and is easy to process and manufacture. In addition, the inclined-hole streamline structure of the non-pneumatic tire of the present invention can effectively reduce the wind resistance during tire rotation, achieving a "wind-breaking" effect.

[0006] To achieve the above object, the technical solution adopted by the present invention is: a non-pneumatic tire, which sequentially includes a tread pattern, a tread, a V-shaped support structure, and a tire inner ring from outside to inside. The V-shaped support structure is formed by arranging V-shaped support bodies in sequence and connecting them end to end. The V-shaped support body is composed of two upper sides, two lower sides, and a height. Among them, the upper side is connected to the tread, the lower side is connected to the tire inner ring, and half of the supplementary angle of the included angle between the two lower sides is the inclination angle of the V-shaped support body, and the extension line of the height passes through the geometric center of the tire. The cross-sectional area of the radial section of the non-pneumatic tire of the present invention is equal everywhere, so the radial material distribution of the tire is uniform. Therefore, when different points of the tire touch the ground, the force conditions and displacement deformations of the tire are similar, so the amount of sinking is similar and the driving stability of the vehicle is relatively high. The design method of the non-pneumatic tire of the present invention includes the following steps:

[0007] S1. Initially determine the tire width W, aspect ratio AR, and tire inner diameter D according to vehicle requirements, market tire specifications, etc., where AR = H / W and H is the section height.

[0008] S2. Calculate the size of the V-shaped support based on the basic tire specification parameters to determine the basic tire contour. The upper side length A of the V-shaped support is A = (πD + 2ARW) / n, where n is the number of tire holes.

[0009] S3. The lower side length B of the V-shaped support is B = πD / n.

[0010] S4. The height h of the V-shaped support is h = ARW - T - t, where T is the tread thickness and t is the inner ring thickness of the tire. The thickness t1 of the V-shaped support can generally be selected as t1 = t or t1 > t, which is determined according to the required load-bearing capacity.

[0011] S5. The inclination angle α of the V-shaped support: tanα = [2(D + 2t)sin(π / n) / W], and the inclination angle α of the V-shaped support structure is α = arctan[2(D + 2t)sin(π / n) / W].

[0012] The non-pneumatic tire of the present invention is formed by casting or injection molding of a polymer material. The polymer is a complex of one or more of polyurethane, synthetic resin, natural rubber, and synthetic rubber.

[0013] At present, polyurethane materials are more commonly used in non-pneumatic tires. Polyurethane materials have high elasticity similar to rubber. At the same time, compared with rubber, polyurethane materials have lower rolling resistance. The low rolling resistance determines that the energy consumption of the tire is smaller, making it more energy-saving and environmentally friendly; polyurethane materials also have better load-bearing capacity and wear resistance. However, the hardness of polyurethane materials is inconsistent, which has a certain impact on tire traction and comfort; and its anti-slip performance and heat dissipation performance are poor. Rubber materials are generally used for tread materials. The tread material is the thicker part of the tire, which generates a large amount of heat, and the heat dissipation conditions are relatively poor compared to the support structure part. Therefore, using rubber materials with better thermal conductivity here can prevent the tread from aging prematurely, and at the same time, the rubber tread has better braking performance. Resin materials are softer than polyurethane materials. As tire materials, they can make the comfort of the tire more excellent. However, their rigidity is weaker, and the simple resin material has poor load-bearing capacity. It needs to be improved to enhance the performance of the resin material before it can be applied to tire production; such as reinforced resin materials strengthened by glass fibers. With the continuous development of material science and the continuous progress of material modification technology, the material selection of non-pneumatic tires is becoming more and more abundant.

[0014] At present, most of the domestic non-pneumatic tires are formed by casting. Casting is a process of injecting liquid monomers or prepolymers (polymers) into a mold under normal pressure and then curing through polymerization to form a product with the same shape as the inner cavity of the mold. It is a chemical reaction forming method. This forming method requires that the melting temperature of the polymer obtained by polymerization should be significantly higher than the melting point of the forming material, and at the same time, the low-molecular by-products produced during the hardening of the liquid material should be as few as possible. However, casting has low requirements for molds and low costs. The tires formed by casting also have high density and uniformity, such as cast polyurethane (CPU). Injection molding is a process of injecting molten materials into a mold at high speed, giving the melt the shape of the mold cavity, and then curing the polymer by cooling (for thermoplastics), heating and cross-linking (for thermosetting plastics), or hot pressing and vulcanizing (for rubbers) to obtain a product. It can form tires with complex outer shapes and has high production efficiency. However, the forming process is relatively complex, it is difficult to process large-size products, and it has high requirements for the fluidity and stability of the materials. Therefore, the selection of the forming method should be considered comprehensively in terms of material properties, process requirements, product performance, etc. In the non-pneumatic tire of the present invention, the V-shaped support structure is formed by arranging V-shaped support bodies in sequence and connecting them end to end. The upper surface of the V-shaped support body is connected to the tread, and the lower surface is connected to the inner circle of the tire. The cross-sectional area of the radial section of the tire is equal everywhere, and the material distribution is uniform. When different points of the tire touch the ground, the sinking amount is similar, and the driving stability and comfort of the vehicle are relatively high. The non-pneumatic tire of the present invention has both the sinking amount stability of the non-pneumatic tire with a continuous support structure and the processability and light weight of the non-pneumatic tire with a traditional support structure. The design method initially determines the tire width W, aspect ratio AR, and tire inner diameter D according to vehicle requirements, market tire specifications, etc. On this basis, calculations are carried out, and in combination with strength requirements, the design method can be adapted to tires for various purposes. Brief Description of the Drawings

[0015] Figure 1 is a schematic structural diagram of a non-pneumatic tire of the present invention;

[0016] Figure 2 is a cross-sectional view of a non-pneumatic tire of the present invention, where W is the cross-sectional width, H is the cross-sectional height, and D is the wheel hub diameter;

[0017] Figure 3 is a non-radial sectional view of a non-pneumatic tire with a V-shaped support structure of the present invention, where α is the inclination angle of the V-shaped support structure;

[0018] In the figure: 1 - tread pattern, 2 - tread, 3 - V-shaped support structure, 4 - inner circle of the tire. Detailed Description of the Invention

[0019] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0020] An embodiment of the present invention provides a non-pneumatic tire and its design method. The non-pneumatic tire of the present invention sequentially includes a tread pattern 1, a tread 2, a V-shaped support structure 3, and a tire inner ring 4 from outside to inside, as Figure 1 shown. The V-shaped support structure 3 is formed by arranging V-shaped supports in sequence and connecting them end to end. The V-shaped support is composed of two upper sides, two lower sides, and a height. The upper side is connected to the tread, and the lower side is connected to the tire inner ring. Half of the supplementary angle of the included angle between the two lower sides is the inclination angle of the V-shaped support, and the extension line of the height passes through the geometric center of the tire. The design method of the non-pneumatic tire of the present invention includes the following steps:

[0021] Step 1: Initially determine the tire width W, aspect ratio AR, and tire inner diameter D according to vehicle requirements, market tire specifications, etc., where AR = H / W, and H is the section height;

[0022] Step 2: Calculate the size of the V-shaped support of the V-shaped support structure 3 according to the basic tire specification parameters to determine the basic contour of the tire.

[0023] The parameters in the design method of the non-pneumatic tire with a V-shaped support structure of the present invention include:

[0024] Tire width W;

[0025] Aspect ratio AR;

[0026] Tire inner diameter D;

[0027] Section height H;

[0028] Upper side length A of the V-shaped support;

[0029] Lower side length B of the V-shaped support;

[0030] Height h of the V-shaped support;

[0031] Inclination angle α of the V-shaped support;

[0032] Thickness t1 of the V-shaped support;

[0033] Thickness T of the tread 2;

[0034] Thickness t of the tire inner ring 4.

[0035] The calculation formulas in the design method of the non-pneumatic tire with a V-shaped support structure of the present invention include:

[0036] The upper side length A of the V-shaped support is A = (πD + 2ARW) / n;

[0037] The lower side length B of the V-shaped support is B = πD / n;

[0038] The height h of the V-shaped support is h = ARW - T - t;

[0039] The inclination angle α of the V-shaped support is α = arctan[2(D + 2t)sin(π / n) / W].

[0040] The above parameters are shown in Figure 2 and Figure 3 as shown.

[0041] In order to introduce a non-pneumatic tire design method provided by an embodiment of the present invention more clearly and in detail,

[0042] the following will be described in combination with specific data.

[0043] Taking the tire specification 195 / 55 / R16 85V as an example, the section width W = 195 mm, the aspect ratio AR is 55%, and the wheel hub diameter D is 15 inches = 381 mm.

[0044] The tread pattern 1 of the non-pneumatic tire in this example adopts an M-shaped pattern with a pattern depth of 10 mm. The number of holes n = 22, the thickness t1 of the V-shaped support = the thickness t of the inner circle 4 of the tire = 10 mm; the thickness T of the tread 2 = 30 mm. Among them, 18 ≤ n ≤ 32. The mechanical properties of the tire of the present invention are tested by a simulation software. When n < 18, the load-bearing capacity of the tire is poor and the deformation is large. When n > 32, when different points of the tire touch the ground, the difference in the sinking amount is large and the driving stability of the vehicle is poor. When n = 22 and the load is 5000 N, the sinking amount of the tire can be measured as 12.2 mm by the simulation software. The sinking rate is the ratio of the sinking amount of the tire to the section height. Usually, the sinking rate of the tire under the rated load is about 12%. The section height of the tire of the present invention is 107 mm, so the sinking rate of the tire in this example is 11.4%, which meets the standard. Therefore, the maximum load-bearing capacity of the non-pneumatic tire in this example is about 5000 N.

[0045] The upper side length A of the V-shaped support is A = (πD + 2ARW) / n = 64.16 mm;

[0046] The lower side length B of the V-shaped support is B = πD / n = 54.41 mm;

[0047] The height h of the V-shaped support is h = ARW - T - t = 67.25 mm;

[0048] The inclination angle α of the V-shaped support is α = arctan[2(D + 2t)sin(π / n) / W] = 30.34°;

[0049] Design according to the non-pneumatic tire design method proposed by the present invention, and the design parameters are shown in the following table:

[0050]

[0051]

[0052] The non-pneumatic tire of this example is cast and formed using a cast polyurethane material.

Claims

1. A non-pneumatic tire, characterized in that: It includes a tread pattern, a tread, a V-shaped support structure, and a tire inner ring from outside to inside in sequence. The V-shaped support structure is formed by arranging V-shaped supports in sequence and connecting them end to end. The V-shaped support is composed of two upper sides, two lower sides, and a height. The upper side is connected to the tread, and the lower side is connected to the tire inner ring. Half of the supplementary angle of the included angle between the two lower sides is the inclination angle of the V-shaped support. The extension line of the height passes through the geometric center of the tire, and the cross-sectional area of the tire radial section is equal everywhere. The determination steps of each parameter are as follows: S1. Initially determine the tire width W, aspect ratio AR, and tire inner diameter D according to vehicle requirements and market tire specifications, where AR = H / W and H is the section height. S2. Calculate the size of the V-shaped support according to the basic tire specification parameters to determine the basic contour of the tire. The upper side length A of the V-shaped support = (πD + 2ARW) / n, where n is the number of tire holes. S3. The lower side length B of the V-shaped support = πD / n. S4. The height h of the V-shaped support = ARW - T - t, where T is the tread thickness and t is the tire inner ring thickness. The thickness t1 of the V-shaped support is selected as t1 = t or t1 > t according to the required load-bearing capacity. S5. The inclination angle α of the V-shaped support: tanα = [2(D + 2t)sin(π / n) / W], and the inclination angle α of the V-shaped support structure = arctan[2(D + 2t)sin(π / n) / W].

2. The non-pneumatic tire according to claim 1, characterized in that: The molding method adopts casting molding or injection molding of polymer materials.

3. The non-pneumatic tire according to claim 2, wherein: The polymer is a complex of one or more of polyurethane, synthetic resin, natural rubber, and synthetic rubber.

4. The non-pneumatic tire according to claim 2, characterized in that: The polymer is an improved reinforced resin material.

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