Low-rolling-resistance tire of two-wheeled electric vehicle

Abstract

The utility model relates to the technical field of rubber products, in particular to a low-rolling-resistance tire of a two-wheeled electric vehicle, which comprises a tread part, a belted layer, a cord fabric layer, a lining layer and a pair of tire bead parts which are sequentially arranged from outside to inside, wherein the tread part comprises two first tread rubber layers and a second tread rubber layer, the first tread rubber layers and the second tread rubber layer are compounded in an embedded mode, the two first tread rubber layers are symmetrically arranged on the shoulder portions of the two transverse sides of the tread part, and the two second tread rubber layers are symmetrically arranged on the shoulder portions of the two transverse sides of the tread part. According to the tire with the composite tread rubber material structure for the two-wheeled electric vehicle, the composite structure of the low-rolling-resistance rubber material and the high-road-holding rubber material is improved, so that the tire has better straight-line driving road-holding property, turning road-holding property and control stability on the premise of not influencing the low-rolling-resistance performance of the tire.

Description

Technical Field

[0001] This utility model relates to the field of rubber product technology, and in particular to a low rolling resistance tire for a two-wheeled electric vehicle. Background Technology

[0002] In recent years, in order to address the "dual carbon" goals and alleviate the global energy crisis, global restrictions on vehicle carbon dioxide emissions have become increasingly stringent. Electric vehicles, due to their outstanding advantage of zero emissions, are in line with the concept of sustainable development and have a very broad development prospect. However, due to the poor charging convenience of electric vehicles and the added weight of the vehicle due to the battery pack, higher requirements have been placed on the design and manufacturing of the corresponding tires. Among them, the low rolling resistance performance of tires is one of the key factors in improving the driving range of electric vehicles. Therefore, the tire industry is increasingly enthusiastic about the research on low rolling resistance technology for electric vehicle tire treads.

[0003] However, tires with low rolling resistance are usually made of low-hysteresis rubber compounds, which have greater rigidity. When driving in a straight line, the tire's grip performance is poor, and when turning, the tire's contact area is significantly reduced. Therefore, the tire's cornering grip and handling stability are also poor, affecting the safety of the tire. This disadvantage is particularly obvious for two-wheeled vehicles that need to be used in situations requiring large body rolls during cornering.

[0004] Therefore, there is an urgent need to develop a tire for two-wheeled electric vehicles that can meet the requirements of low rolling resistance for normal driving and also reduce the risk of sideslip during cornering, thus satisfying customers' expectations for a balance between energy conservation, environmental protection, and safety. Utility Model Content

[0005] The purpose of this invention is to address the shortcomings of existing technologies where low rolling resistance tires are typically made of low-hysteresis rubber compounds, have high rigidity, and poor grip when driving in a straight line. This invention proposes a low rolling resistance tire for two-wheeled electric vehicles.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] Design a low rolling resistance tire for a two-wheeled electric vehicle, including:

[0008] From the outside to the inside, the tire tread, belt layer, ply layer, inner liner layer, and a pair of bead sections are arranged sequentially.

[0009] The tread portion includes two first tread rubber layers and a second tread rubber layer. The first tread rubber layers and the second tread rubber layers are interlocked and composite. The two first tread rubber layers are symmetrically arranged on the shoulders of the tread portion on both sides in the lateral direction. The second tread rubber layer is arranged in the central area of ​​the tread portion and on the sidewall.

[0010] Furthermore, the cord layer spans a pair of bead portions to form a folded-back portion that folds back from the inner side of the tire axial direction to the outer side, and the inner liner and bead portions sequentially surround to form a full circle.

[0011] Furthermore, the belt layer includes at least one of a spirally wound yarn belt layer or a fabric-bonded belt layer.

[0012] Furthermore, the belt layer includes at least a spirally wound yarn belt layer and a fabric-bonded belt layer;

[0013] The spiral wound cord layer is disposed on the radial outer side of the fabric bonding cord layer. The width of the spiral wound cord layer is smaller than that of the fabric bonding cord layer. The cord winding density of the spiral wound cord layer is set to 20-30 cords / inch. The cord of the fabric bonding cord layer is inclined at an angle of 30-90 degrees relative to the circumference of the tire.

[0014] Furthermore, the width of the first tread rubber layer is set to be 27.5% to 45% of the tread perimeter width between the two tread edges measured along the tread surface.

[0015] Furthermore, the first tread rubber layer has a rectangular, arc-shaped, or triangular structure.

[0016] Furthermore, the vertical distance from the center point of the tread edge of the first tread rubber layer to the bottom is no greater than 3 / 4 of the tread rubber thickness.

[0017] Furthermore, the width of the second tread rubber layer is set to 10% to 45% of the tread perimeter width between the two tread edges measured along the tread surface.

[0018] Furthermore, the outer periphery of the tread surface is provided with a raised or recessed pattern, and the number of ply layers is one to three.

[0019] The present invention proposes a low rolling resistance tire for two-wheeled electric vehicles, the advantages of which are as follows: The present invention develops a tire for two-wheeled electric vehicles with a composite tread compound structure. By improving the composite structure of low rolling resistance compound and high grip compound, the tire has better straight-line grip, cornering grip and handling stability without affecting the low rolling resistance performance of the tire. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the structure of this utility model;

[0021] Figure 2 This is a schematic diagram of the cross-sectional structure of the tire tread of this utility model.

[0022] In the diagram: 1. Tread layer; 1A. First tread rubber layer; 1B. Second tread rubber layer; 2. Belt layer; 3. Cord layer; 4. Inner liner layer; 5. Bead section. Detailed Implementation

[0023] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments.

[0024] Reference Figure 1-2 As an embodiment of the present utility model, it discloses a low rolling resistance tire for a two-wheeled electric vehicle. Specifically, the tire includes a tread portion 1, a belt layer 2, a ply layer 3, an inner liner layer 4, and a pair of bead portions 5 arranged sequentially from the outside to the inside.

[0025] The tread portion 1 includes two first tread rubber layers 1A and a second tread rubber layer 1B. The first tread rubber layer 1A and the second tread rubber layer 1B are interlocked and composite. The two first tread rubber layers 1A are symmetrically arranged on the shoulders of the two sides of the tread portion 1 in the lateral direction. The second tread rubber layer 1B is arranged in the central area and the side part of the tread portion 1. That is, the second tread rubber layer 1B serves as the bottom of the tread rubber base and only rises to the tread in the central area.

[0026] Specifically, in this embodiment, the second tread rubber layer 1B is mainly responsible for low rolling resistance, wear resistance and low heat generation when the tire is driving straight, while the first tread rubber layer 1A is mainly responsible for the grip when the tire is driving straight and turning. Different rubber combinations are used according to the actual performance requirements of each part of the tire, which improves the grip while ensuring low rolling resistance of the tire for two-wheeled electric vehicles.

[0027] In some embodiments, the cord layer 3 of the present invention spans a pair of bead portions 5 to form a folded-back portion that folds back from the inner side of the tire axial direction to the outer side, and the inner liner layer 4 and the bead portion 5 are sequentially arranged around one circumference.

[0028] Furthermore, the belt layer 2 includes at least one of a spiral wound belt layer of yarn or a fabric-bonded belt layer. Of course, both the spiral wound belt layer of yarn and the fabric-bonded belt layer are existing technologies, so their structures will not be described in detail.

[0029] In a preferred embodiment, the belt layer 2 of the present invention includes at least a spiral wound belt layer of yarn and a fabric-bonded belt layer;

[0030] The spiral wound belt layer of the curtain yarn is disposed radially outside the fabric bonding belt layer, and the width of the spiral wound belt layer of the curtain yarn is smaller than that of the fabric bonding belt layer. Preferably, in this embodiment, the width of the spiral wound belt layer of the curtain yarn is set to 90-95% of the width of the fabric bonding belt layer.

[0031] The cord winding density of the spiral-wound belt layer is set to 20-30 cords / inch. The cord of the belt layer is inclined at an angle of 30-90 degrees relative to the tire circumference. This ensures the tire's support and handling, while optimizing the tire's overall performance and durability, and balancing the tire's grip, rolling resistance, wear resistance and comfort.

[0032] The above description uses a single or double layer of the belt layer 2 as an example, which is a spiral wound belt layer of the curtain yarn and a belt layer bonded to the curtain fabric. Of course, in other embodiments, those skilled in the art will know that the belt layer 2 can also be configured as a three-layer structure, such as a composite layer of a belt layer bonded to the curtain fabric, a spiral wound belt layer of the curtain yarn, and a belt layer bonded to the curtain fabric. That is, the belt layer 2 can be configured as a composite layer structure of one to three layers. The specific choice can be made by those skilled in the art, and will not be elaborated here.

[0033] In some embodiments, the width of the first tread rubber layer 1A in this invention is set to 27.5% to 45% of the tread periphery width between the two tread edges measured along the surface of the tread 1. The two first tread rubber layers 1A are discontinuous in the tread axial direction and are symmetrically fitted on the shoulders of the tread on both sides in the lateral direction. This can maintain better grip performance when the two-wheeled electric vehicle is traveling in a straight line and making large side turns.

[0034] Based on the above embodiments, in this embodiment, the first tread rubber layer 1A is rectangular, arc-shaped, or triangular. This utility model does not have any particular limitation on the shape of the high-grip rubber composition with a definite width and maximum radial distance. Those skilled in the art can also use other shape designs. Of course, other shapes not listed in this embodiment should also be covered within the protection scope of this utility model. That is, this utility model optimizes the shape of the first tread rubber layer 1A, which can have better process feasibility while ensuring tire grip performance.

[0035] If the first tread rubber layer 1A is too thin in the radial direction, the tire's cornering grip performance will be poor. If it is too thick, on the one hand, the tire shoulder rigidity will be insufficient, affecting the cornering stability. On the other hand, the tire shoulder will have excessive lag and generate too much heat, affecting the tire's service life. Therefore, in this embodiment, the vertical distance from the center point of the tread edge of the first tread rubber layer 1A to the bottom is not greater than 3 / 4 of the tread rubber thickness. More preferably, the vertical distance from the center point of the tread edge of the first tread rubber layer 1A to the bottom is 1 / 3 to 1 / 2 of the tread thickness. The lower inner side is inlaid with low rolling resistance rubber. In this way, while maintaining grip, the tire's cornering stability and low heat generation can be improved.

[0036] In this embodiment, by optimizing the radial thickness of the first tread rubber layer 1A and embedding the second tread rubber layer 1B on the inner side below, the tire as a whole has lower heat generation and can improve the shoulder rigidity, thereby improving the tire's cornering stability while maintaining grip.

[0037] Based on the above embodiments, the second tread rubber layer 1B is disposed in the central area of ​​the tread and the sidewall. If the width of the second tread rubber layer 1B in the central area of ​​the tread transverse axis is set too wide, it will be difficult to ensure grip performance; if it is set too narrow, it will be difficult to ensure rolling resistance performance. Therefore, in this embodiment, the width of the second tread rubber layer 1B is set to 10% to 45% of the outer perimeter width of the tread between the two tread edges measured along the surface of the tread 1. This embodiment optimizes the width of the second tread rubber layer 1B in the central area of ​​the tread, and has better straight-line driving and cornering grip performance while ensuring low rolling resistance.

[0038] In other words, this invention enables the tire to have better straight-line grip, cornering grip and handling stability without affecting the tire's low rolling resistance performance.

[0039] More specifically, the first tread rubber layer 1A is made of a high-grip rubber composition. In this embodiment, the first tread rubber layer 1A is a rubber assembly comprising natural rubber, carbon black and tackifying resin.

[0040] The second tread layer 1B uses a rubber composition with low rolling resistance, low heat generation, and high wear resistance. Specifically, the second tread layer 1B is a rubber assembly including styrene-butadiene rubber, silica, carbon black, and a low rolling resistance modifier.

[0041] In addition, the outer periphery of the tread surface 1 in this utility model is provided with a concave-convex pattern. The pattern can enhance the basic friction between the tire and the ground. The number of ply layers 3 is one to three, that is, the ply layer 3 in this embodiment can also be set as a composite structure of one to three layers.

[0042] The specific implementation details are as follows:

[0043] Example 1

[0044] In this embodiment, the first tread rubber layer 1A is made of natural rubber, carbon black and tackifying resin as the main materials, and is rectangular in shape. It is symmetrically fitted on the shoulders of the two tread sides. The width of one side is set to 27.5% of the tread perimeter width between the two tread edges measured along the surface of the tread. The radial thickness of one side is set to 3 / 4 of the tread thickness, which is the vertical distance from the center point of the tread edge of the first tread rubber layer 1A to the bottom.

[0045] The second tread layer 1B is made of styrene-butadiene rubber, silica, carbon black and low rolling resistance modifier as the main materials, and is set in the center area and sidewall of the tread. The width of the center area of ​​the tread is set to 45% of the outer width of the tread perimeter between the two tread edges measured along the surface of the tread.

[0046] Example 2

[0047] In this embodiment, the first tread rubber layer 1A is made of natural rubber, carbon black and tackifying resin as the main materials. It is rectangular in shape and symmetrically fitted on the shoulders of the two tread sides. The width of one side is set to 45% of the tread perimeter width between the two tread edges measured along the surface of the tread. The radial thickness of one side is set to 3 / 4 of the tread thickness, which is the vertical distance from the center point of the tread edge of the first tread rubber layer 1A to the bottom.

[0048] The second tread layer 1B is made of styrene-butadiene rubber, silica, carbon black and low rolling resistance modifier as the main materials, and is set in the center area and sidewall of the tread. The width of the center area of ​​the tread is set to 10% of the outer width of the tread between the two tread edges measured along the surface of the tread.

[0049] According to the parameter settings of the tire surface 1 in Embodiment 1 and Embodiment 2, the first tread rubber layer 1A and the second tread rubber layer 1B of the tire surface 1 of this utility model are fed into the feed port of their respective screw extruders, and then extruded through their respective screw extruders and flow channels. They are then pressed out through the die-shaped component and arranged into a preset shape. Finally, the tire surface 1 is compoundly pressed out through the extrusion die-shaped component.

[0050] Then, following conventional processes, the belt layer 2, cord layer 3, inner liner layer 4, and a pair of bead portions 5 are molded and assembled into a tire semi-finished product, which is then vulcanized into a finished tire. The inner liner layer 4 and the bead portions 5 are sequentially wrapped around to form a circumference. The belt layer 2 is composed of a layer of aromatic polyamide cord yarn wound at a 0° angle along the tire circumference. The cord layer 3 is composed of two layers of nylon-6 cord fabric. The cord layer 3 spans across a pair of bead portions to form a folded-back portion that folds back from the inner side of the tire axial direction to the outer side. The outer periphery of the tread is provided with a concave-convex pattern. Specifically, in this embodiment, finished tires of the front and rear wheel specifications of 2.75-10 are manufactured according to the above conditions.

[0051] In addition, as a comparative example, a tire made of a single low rolling resistance rubber composition for the tread rubber was prototyped. The comparative example tire, apart from the above-mentioned aspects, has substantially the same structure as the tire of the embodiment. The wear resistance, rolling resistance during straight-line driving, grip performance, cornering grip performance, and handling stability of each test tire were tested.

[0052] The specific testing method is as follows:

[0053] 1. Rolling resistance performance: The rolling resistance coefficient of the finished tire is tested according to the ISO28580-2018 standard. The result is expressed as a relative index. The larger the value, the better the rolling resistance performance.

[0054] 2. Wear resistance: The wear resistance is determined by the thickness of the remaining rubber in the center of the tread after the tire has traveled a specific distance on a normal road. The result is an index with the rubber thickness of the comparative example as 100. The higher the value, the greater the rubber thickness and the better the wear resistance.

[0055] 3. Tire grip and handling stability: The grip and handling stability of the front and rear tires during cornering are evaluated when the driver is driving straight and turning corners of various radii within a speed range of 15-50 km / h. The results are expressed as a relative index, with a higher index indicating better performance.

[0056] Comparison of test results:

[0057] Table 1. Tire test results of examples and comparative examples

[0058]

[0059] As shown in Table 1 above, the evaluation results indicate that the wear resistance and rolling resistance of the test tires in Examples 1 and 2 are comparable to those of the comparative example when driving straight, while their straight-line grip, cornering grip, and handling stability are significantly better. Therefore, it is clear that the solution of this invention can achieve better cornering grip and handling stability without compromising the tire's low rolling resistance.

[0060] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model, based on the technical solution and the inventive concept of the present utility model, should be included within the protection scope of the present utility model.

Claims

1. A low rolling resistance tire for a two-wheeled electric vehicle, characterized in that, include: The tire tread (1), belt layer (2), ply layer (3), inner liner layer (4), and a pair of bead sections (5) are arranged sequentially from the outside to the inside. The tread portion (1) includes two first tread rubber layers (1A) and a second tread rubber layer (1B). The first tread rubber layer (1A) and the second tread rubber layer (1B) are interlocked and composite. The two first tread rubber layers (1A) are symmetrically arranged on the shoulders of the tread portion (1) on both sides in the lateral direction. The second tread rubber layer (1B) is arranged in the central area and the side part of the tread portion (1).

2. The low rolling resistance tire for a two-wheeled electric vehicle according to claim 1, characterized in that: The cord layer (3) spans a pair of bead portions (5) to form a folded-back portion that folds back from the inner side of the tire axial direction to the outer side, and the inner liner layer (4) and the bead portion (5) are arranged around the tire in sequence to form a circumference.

3. The low rolling resistance tire for a two-wheeled electric vehicle according to claim 1, characterized in that: The belt layer (2) includes at least one of the following: a spiral wound belt layer or a fabric-bonded belt layer.

4. The low rolling resistance tire for a two-wheeled electric vehicle according to claim 1, characterized in that: The belt layer (2) includes at least a spiral wound belt layer of yarn and a fabric-bonded belt layer; The spiral wound cord layer is disposed on the radial outer side of the fabric bonding cord layer. The width of the spiral wound cord layer is smaller than that of the fabric bonding cord layer. The cord winding density of the spiral wound cord layer is set to 20-30 cords / inch. The cord of the fabric bonding cord layer is inclined at an angle of 30-90 degrees relative to the circumference of the tire.

5. A low rolling resistance tire for a two-wheeled electric vehicle according to claim 1, characterized in that: The width of the first tread rubber layer (1A) is set to be 27.5% to 45% of the tread perimeter width between the two tread edges measured along the surface of the tread (1).

6. A low rolling resistance tire for a two-wheeled electric vehicle according to claim 1 or 5, characterized in that: The first tread rubber layer (1A) is rectangular, arc-shaped or triangular in shape.

7. A low rolling resistance tire for a two-wheeled electric vehicle according to claim 1 or 5, characterized in that: The vertical distance from the center point of the tread edge of the first tread layer (1A) to the bottom is no greater than 3 / 4 of the tread thickness.

8. A low rolling resistance tire for a two-wheeled electric vehicle according to claim 1 or 5, characterized in that: The width of the second tread rubber layer (1B) is set to 10% to 45% of the tread perimeter width between the two tread edges measured along the surface of the tread (1).

9. A low rolling resistance tire for a two-wheeled electric vehicle according to any one of claims 1-5, characterized in that: The outer periphery of the tread surface (1) is provided with a concave-convex pattern, and the number of layers of the plywood layer (3) is one to three.

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