A load bearing bicycle pneumatic tire

Abstract

The application discloses a heavy-duty bicycle pneumatic tire, which comprises a tread, a carcass and a central area, a plurality of long main grooves with large span cross the whole tread, the long main grooves are arched and point to the running direction of the tire, the long main grooves have transverse grooves parallel to the axial direction of the tire at the central position of the central area, and short auxiliary grooves are arranged between the circumferentially spaced long main grooves. The application optimizes the tread pattern block and the anti-skid element, the corresponding carcass of the central area is provided with a double reinforcement structure of reinforced glue and reinforced yarn, and the safety requirements of heavy load, anti-puncture and anti-skid of the vehicle type are met.

Description

Technical Field

[0001] This invention relates to the field of pneumatic tire technology, specifically to a pneumatic tire for heavy-duty bicycles. Background Technology

[0002] Cargo bikes, as the name suggests, are cargo bicycles. Unlike ordinary bicycles or electric bicycles, cargo bikes have a greater load capacity (typically over 200kg). Their electric assist makes them convenient and safe for short-distance urban transport, and they are also commonly used for family outings and mobile vending. They have become very popular in Western countries in recent years, and many bicycle manufacturers in my country are also focusing on the production and export of this type of bicycle. Currently, cargo bikes are equipped with standard bicycle tires, which, after a period of heavy-duty use, are prone to insufficient puncture resistance and tire slippage, posing safety hazards. While the industry has strengthened the tire structure, these problems have not been completely resolved. Figure 1 This is a reinforced tire carcass structure. The 20' ply layer has been upgraded from a single-layer overlap in conventional bicycle tires to a two-layer overlap, significantly increasing the overall carcass strength and improving load-bearing capacity. However, this reinforced structure does not specifically enhance puncture and burst resistance, especially in the main contact patch area, where the puncture and burst resistance is not significant. Under heavy loads, this area remains highly susceptible to punctures. Furthermore, conventional bicycle tires, due to insufficient tread strength under heavy loads, are prone to wear or abnormal wear, resulting in insufficient edge effect and a sharp decrease in tread grip, making them prone to slippage during straight-line braking or cornering. Summary of the Invention

[0003] The purpose of this invention is to provide a pneumatic tire for heavy-duty bicycles to solve the problems mentioned in the background art.

[0004] To achieve the above objectives, the present invention provides the following technical solution: a heavy-duty bicycle pneumatic tire, comprising a tread, a carcass, and a central area, with several long main grooves spanning a large distance across the entire tread. These main grooves are arched and point towards the tire's direction of travel. At the center of the central area, each main groove has a transverse groove parallel to the tire's axial direction. Short secondary grooves are arranged between the circumferentially spaced main grooves. The main grooves and secondary grooves divide the tread into multiple tread pattern groups. Each tread pattern group includes a central tread block spanning the tread centerline CL and side tread block groups located on both sides of the tread. Shallow grooves are provided within the central area. The tire has a crisscross pattern on both sides of the center line CL of the tread, arranged in a figure-eight pattern and in the direction of tire travel. The tread blocks on the sidewalls that are in contact with the ground when turning are arranged with longitudinal and transverse patterns. The tread blocks are composed of alternating longitudinal and transverse patterns. The tire carcass in the central area corresponding to the radial inner part is equipped with a double reinforcement structure of reinforcing rubber and reinforcing yarn. The tire carcass in the central area corresponding to the radial inner part contains two layers of cord fabric bonded together. The two ends of the two layers of cord fabric overlap in the central area corresponding to the radial inner part. Reinforcing rubber is placed on the overlap of the cord layers and between the rubber materials in the central area. Reinforcing yarn is sandwiched inside the overlap of the cord layers.

[0005] Preferably, the short secondary groove includes a first short secondary groove and a second short secondary groove. The first short secondary groove is located in the central area near the center line CL of the tread, and the second short secondary groove is located outside the central area near the edge of the tread. The two short secondary grooves are inclined straight grooves, and the direction of the grooves is opposite to the tire's driving direction.

[0006] Preferably, the central zone unfolded width W2 is limited to 50%-70% of the tread unfolded width W1, and the axial width W3 of the transverse groove of the long main groove is designed to be 25%-50% of the central zone unfolded width W2.

[0007] Preferably, the central tread block is wrench-shaped and is staggered along the tire circumference. The central tread block has a lateral portion and a bent portion, with the bent portion tilting to transition into the side tread block group.

[0008] Preferably, the side tread block group consists of a first side tread block located in the central area and a second and third side tread blocks located at the edge of the tread, and the three tread blocks of the side tread block group are quadrilateral.

[0009] Preferably, the shallow groove has an end close to the tread centerline CL and a tail close to the edge of the central area, and the shallow groove extends on the surface of both the central tread block and the first side tread block within the central area.

[0010] Preferably, each longitudinal and transverse rib group consists of three convex strips as a group. The longitudinal rib group is parallel to the tire circumference, and the transverse rib group is parallel to the tire axial direction. The longitudinal and transverse ribs are not connected. The cross-section of the longitudinal and transverse ribs is defined as triangular or trapezoidal.

[0011] Preferably, the ribs in the same longitudinal or transverse rib group are at the same angle, and the center of gravity of the ribs in the same group is perpendicular to the tire tread.

[0012] Preferably, the center of gravity of the central ridge of the longitudinal or transverse ridge group is perpendicular to the tread, and the centers of gravity of the two ridges on both sides are inclined relative to the tread and are symmetrically opposite.

[0013] Preferably, the reinforcing adhesive is composed of a rubber compound with puncture resistance, and the reinforcing yarn has 1-2 layers.

[0014] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0015] This invention specifically refers to a heavy-duty bicycle tire. The width W2 of the central area of ​​the main contact patch is limited to 50%-70% of the tread width W1, and the width W3 of the lateral grooves is 25%-50% of the central area width W2. Arched long main grooves and reverse short secondary grooves are cut into wrench-shaped central tread blocks and side tread block groups. The central lateral portion ensures stable support and wear resistance under heavy loads. Shallow grooves arranged in a figure-eight pattern are added to the central area to balance rigidity and improve straight-line grip and anti-slip performance. The surface of the side tread block group is configured with alternating longitudinal and transverse treads, which are parallel to the tire's circumferential and axial directions and are spaced apart without intersecting. Raised ribs... The cross-section is triangular or trapezoidal, with a shape that is narrower at the top and wider at the bottom, providing excellent stability. Ideally, the center of gravity of the central convex strip in the same group is perpendicular to the tread, while the centers of gravity of the two side convex strips are tilted and symmetrically opposite, providing multi-directional edge effects at different angles to enhance grip and anti-skid performance. In addition, reinforcing rubber is applied on the overlapping double cord layers, and reinforcing yarn is sandwiched inside the overlapping layers. The double-material reinforcement structure can significantly improve the tire strength and puncture resistance, thereby optimizing the tread pattern blocks and anti-skid elements. The corresponding tire body in the central area is equipped with a double reinforcement structure of reinforcing rubber and reinforcing yarn to meet the vehicle's heavy load, puncture resistance, and anti-skid safety requirements. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the cross-sectional structure of an existing tire;

[0017] Figure 2 This is a schematic diagram of the cross-sectional structure of the tire of the present invention;

[0018] Figure 3 This is a schematic diagram of the first tread pattern of the tire tread of the present invention;

[0019] Figure 4 This is a schematic diagram of the second tread pattern of the tire tread of the present invention;

[0020] Figure 5 This is a schematic diagram of the longitudinal and transverse stripe structure of the present invention;

[0021] Figure 6 for Figure 5 The first schematic diagram of A-A' in the first state;

[0022] Figure 7 for Figure 5 The second schematic diagram of A-A' in the first state;

[0023] Figure 8 for Figure 5 The third schematic diagram of A-A' in the first state;

[0024] Figure 9 for Figure 5 The first schematic diagram of A-A' in the second state;

[0025] Figure 10 for Figure 5 The second schematic diagram of A-A' in the second state;

[0026] Figure 11 for Figure 5 The third schematic diagram of A-A' in the second state;

[0027] Figure 12 This is a schematic diagram of the reinforcing yarn of the present invention when it is a single layer;

[0028] Figure 13 This is a schematic diagram of the reinforcing yarn of the present invention when it is a two-layer structure.

[0029] In the diagram: 1. Tread; 2. Carcass; A1. Central area; 11. Long main groove; 11a. Transverse groove; 12. Short secondary groove; 12a. First short secondary groove; 12b. Second short secondary groove; 13. Central tread block; 14. Side tread block group; 14a. First side tread block; 14b. Second side tread block; 14c. Third side tread block; 15. Shallow groove; 16. Longitudinal and transverse ribs; 16a. Longitudinal rib group; 16b. Transverse rib group; 20. Cord layer; 30. Reinforcing rubber; 31. Reinforcing yarn. Detailed Implementation

[0030] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] In the description of this application, it should be noted that, unless otherwise explicitly specified and limited, the terms "installed," "equipped with," and "connected," etc., should be interpreted broadly. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0032] The components of this application, including tread 1, carcass 2, central zone A1, long main groove 11, transverse groove 11a, short secondary groove 12, first short secondary groove 12a, second short secondary groove 12b, center tread block 13, side tread block group 14, first side tread block 14a, second side tread block 14b, third side tread block 14c, shallow groove 15, longitudinal and transverse stripes 16, longitudinal stripe group 16a, transverse stripe group 16b, cord layer 20, reinforcing rubber 30, and reinforcing yarn 31, are all general standard parts or parts known to those skilled in the art. Their structure and principle can be learned by those skilled in the art through technical manuals or conventional experimental methods.

[0033] Please see Figures 2-13 A pneumatic tire for heavy-duty bicycles includes a tread 1 and a carcass 2. The central area A1 of the tread 1 is the main contact area of ​​the tire. Considering the actual use of heavy-duty bicycle tires, the unfolded width W2 of the central area A1 is limited to 50%-70% of the unfolded width W1 of the tread 1. Several long main grooves 11 with large spans traverse the entire tread 1. The long main grooves 11 are arched and point towards the tire's driving direction. At the center of the central area A1, each long main groove 11 has a transverse groove 11a parallel to the tire's axial direction. Short secondary grooves 12 are arranged between the circumferentially spaced long main grooves 11. The long main grooves 11 and short secondary grooves 12 divide the tread 1 into multiple tread pattern groups. Each tread pattern group includes a central tread block 13 spanning the tread centerline CL and side tread block groups 14 located on both sides of the tread 1. Shallow grooves 15 are provided within the central area A1. The tire tread is arranged in a figure-eight pattern on both sides of the center line CL and in the direction of tire travel. The tread blocks 14 that are in contact with the ground when turning are configured with longitudinal and transverse treads 16, which can improve the tire's anti-skid safety when turning. The longitudinal and transverse treads 16 are composed of alternating longitudinal tread groups 16a and transverse tread groups 16b. The tire carcass 2 corresponding to the radial inner part of the central area A1 is configured with a double reinforcement structure of reinforcing rubber 30 and reinforcing yarn 31, which can meet the requirements of heavy load, puncture resistance and anti-skid safety of the vehicle, and can improve the load-bearing capacity and explosion-proof safety of the tire tread 1 of the present invention. The tire carcass 2 corresponding to the radial inner part of the central area A1 includes a ply yarn layer 20 after two layers of cord fabric are bonded together. The two ends of the two layers of cord fabric overlap in the radial inner part of the central area A1. Reinforcing rubber 30 is set on the overlapping ply yarn layer 20 and between the rubber material in the central area A1, and reinforcing yarn 31 is sandwiched inside the overlapping ply yarn layer 20.

[0034] The short groove 12 includes a first short groove 12a and a second short groove 12b. The first short groove 12a is located in the central area A1 near the center line CL of the tread, and the second short groove 12b is located outside the central area A1 near the edge of the tread 1. Both short grooves 12 are inclined straight grooves, and the direction of the grooves is opposite to the tire travel direction.

[0035] The central zone A1 unfolded width W2 is limited to 50%-70% of the tread 1 unfolded width W1. The axial width W3 of the transverse groove 11a of the long main groove 11 is designed to be 25%-50% of the central zone A1 width W2. This can increase the lateral coefficient of the central zone A1, giving the tread 1 a wide visual appearance. If the axial width W3 of the transverse groove 11a is set too narrow, the lateral coefficient of the central zone A1 will be low, and the strength cannot be effectively improved. However, if the axial width W3 of the transverse groove 11a is set too large, the lateral coefficient of the central zone A1 will be too high, and it will be prone to abnormal wear under heavy load, which will lead to slippage problems.

[0036] The center tread block 13 is wrench-shaped and is staggered along the tire circumference, which can form a large contact area in the central area A1 of the main contact area. The center tread block 13 has a lateral part and a bent part. The lateral part of the tread block has high strength, which can ensure stable support and uniform wear of the tire after heavy load. The bent part is inclined to the side tread block group 14 to maintain rigidity balance and avoid abnormal local wear of the tread block.

[0037] The side pattern block group 14 consists of a first side pattern block 14a located in the central area A1, a second side pattern block 14b located at the edge of the tread 1, and a third side pattern block 14c. The three pattern blocks of the side pattern block group 14 are quadrilateral.

[0038] The shallow groove 15 has its end close to the center line CL of the tread and its tail close to the edge of the central area A1. The shallow groove 15 extends on the surface of the central tread block 13 and the first side tread block 14a in the central area A1. The shallow groove 15 has its end close to the center line CL of the tread and its tail close to the edge of the central area A1. This can balance the rigidity of the tread blocks in the central area A1 and increase the grip and edge effect of the central area A1 when it touches the ground, thereby improving the grip of the straight contact area and preventing slippage.

[0039] The tread block group 14, which is mainly in contact with the ground during cornering, is provided with longitudinal and transverse treads 16 to improve the tire's cornering anti-skid safety. The longitudinal and transverse treads 16 are composed of alternating longitudinal tread groups 16a and transverse tread groups 16b. Each longitudinal tread group 16a and transverse tread group 16b consists of three convex strips as a group. The longitudinal tread group 16a is parallel to the tire circumference, and the transverse tread group 16b is parallel to the tire axial direction. The longitudinal and transverse treads are not connected. The cross-section of the convex strips of the longitudinal and transverse treads 16 is limited to a triangle or trapezoid. The shape of being narrower at the top and wider at the bottom provides better stability and is not easily worn under heavy load. It can effectively and persistently perform anti-skid function. The convex strips in the same group can be at the same angle, that is, the center of gravity of the convex strips in the same group is perpendicular to the tread 1. More preferably, the center of gravity of the central convex strip in the same group is vertical, and the center of gravity of the two convex strips on both sides is inclined relative to the tread 1 and is symmetrical and opposite. Figure 6-8 The example shown is an embodiment with 16 longitudinal and transverse raised strips and a triangular cross-section: Figure 6 The center of gravity of the convex strips in the same group is perpendicular to the tread 1; Figure 7 The center of gravity of the central convex strip is vertical, while the centers of gravity of the two side convex strips are tilted outwards at equal but opposite angles. Figure 8 With the center of gravity of the central protrusion vertical, the centers of gravity of the two side protrusions are inclined inwards at equal but opposite angles. When grounded, the protrusions of the triangular cross section form intermittent line contact with the ground, generating dense shear force. Figure 9-11The example shown is an embodiment where the cross-section of the longitudinal and transverse treads 16 is trapezoidal. This embodiment is largely the same as the one described above, and the similarities will not be elaborated in detail. The differences are as follows: when grounding, the trapezoidal cross-section treads form an intermittent surface contact with the ground, providing multi-directional edge effects. With this design, the longitudinal and transverse treads 16 have good stability due to their narrow upper and wide lower shape. Each set of treads has three different grounding angles. The combination of longitudinal and transverse treads allows the side tread block group 14 to more comprehensively and sensitively respond to road conditions. Compared with the conventional coarsening treads of existing tires, the longitudinal and transverse treads 16 are not only less prone to wear, but also effectively enhance grip on dry surfaces and break through the water film on wet and slippery surfaces to prevent slippage, significantly improving turning safety.

[0040] The tire carcass 2 corresponding to the radial inner part of the central area A1 includes two layers of plywood 20 bonded together. The two ends of the two plywood overlap at the radial inner part of the central area A1. Reinforcing rubber 30 is provided on the overlap of the plywood 20 and between the rubber materials in the central area A1. The reinforcing rubber 30 is composed of rubber material with puncture resistance. Reinforcing yarn 31 is sandwiched inside the overlap of the plywood 20. The length and number of layers of reinforcing yarn 31 can be adjusted according to the vehicle's load. Figure 12 In an embodiment where the reinforcing yarn 31 is a single layer, the extension width of the reinforcing yarn 31 needs to cover the unfolded width W2 of the central area A1, and may also extend to the tire sidewall. Figure 13 In the embodiment where the reinforcing yarn 31 is a two-layer structure, the two layers of reinforcing yarn 31 need to overlap at the corresponding position in the central area A1. The width of the overlap can be adjusted according to the load. The reinforcing yarn 31 can be a high-strength fabric such as nylon, polyester, or synthetic yarn, and more preferably a fabric made of aramid such as KEVLAR. The reinforcing yarn 31 sandwiched inside the overlapping cord layer 20 has high stability and is not easily deformed and separated from the cord layer 20 due to heavy load. Furthermore, due to the high strength of the fabric structure, after the reinforcing yarn 31 and the reinforcing adhesive 30 are combined, the tire body corresponding to the central area A1 has a dual-material reinforcement structure with both inner and outer materials, which can significantly improve the tire body strength and puncture resistance, meeting the requirements of heavy-load and explosion-proof safety of vehicles.

[0041] In use, the width W2 of the central zone A1 of the main contact area is limited to 50%-70% of the tread width W1, and the width W3 of the lateral grooves 11a is 25%-50% of the width W2 of the central zone A1. The arched long main groove 11 and the reverse short secondary grooves 12 are cut into wrench-shaped central tread blocks 13 and side tread block groups 14. The central lateral portion ensures stable support and wear resistance under heavy loads. Shallow grooves 15 arranged in a figure-eight pattern are added to the central zone A1 to balance rigidity and improve straight-line grip and anti-skid performance. The surface of the side tread block group 14 is equipped with alternating longitudinal and transverse treads 16, which are parallel to the tire's circumferential and axial directions respectively and are spaced apart. The cross-section of the strip is triangular or trapezoidal, with a shape that is narrower at the top and wider at the bottom, which provides good stability. Preferably, the center of gravity of the central convex strip in the same group is perpendicular to the tread, and the centers of gravity of the two side convex strips are inclined and symmetrically opposite. Different angles provide multi-directional edge effects, enhancing grip and anti-skid performance. In addition, a reinforcing rubber 30 is provided on the overlapping double cord layers 20, and a reinforcing yarn 31 is sandwiched inside the overlapping layer. The double-material reinforcement structure can significantly improve the tire body strength and puncture resistance, thereby optimizing the tread pattern blocks and anti-skid elements. The corresponding tire body 2 in the central area A1 is equipped with a double reinforcement structure of reinforcing rubber 30 and reinforcing yarn 31 to meet the vehicle's heavy load, puncture resistance, and anti-skid safety requirements.

[0042] It should be noted that the end closer to the center line CL of the tread represents the inner end, and the end farther from the center line CL of the tread represents the outer end. Furthermore, this invention specifically refers to the specifications of heavy-duty bicycle tires that can carry a load of 120kg or more per tire.

[0043] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A pneumatic tire for heavy-duty bicycles, comprising a tread (1), a tire body (2), and a central area (A1), characterized in that: Several long main grooves (11) with large spans traverse the entire tread (1). The long main grooves (11) are arched and point in the direction of tire travel. The long main grooves (11) have transverse grooves (11a) parallel to the tire axis at the center of the central area (A1). Short secondary grooves (12) are arranged between the circumferentially spaced long main grooves (11). The long main grooves (11) and short secondary grooves (12) divide the tread (1) into multiple tread groups. Each tread group includes: a central tread block (13) that crosses the tread centerline CL and side tread block groups (14) located on both sides of the tread (1). Shallow grooves (15) are provided in the central area (A1). They are arranged in a figure-eight pattern on both sides of the tread centerline CL and are in the direction of tire travel. Longitudinal and transverse treads (16) are arranged on the surface of the side tread block group (14) that mainly touches the ground when turning. The longitudinal and transverse treads (16) are formed by the longitudinal tread group (16). a) and transverse stripe groups (16b) are alternately composed. The central area (A1) corresponding to the radial inner tire body (2) is configured with a double reinforcement structure of reinforcing rubber (30) and reinforcing yarn (31). The central area (A1) corresponding to the radial inner tire body (2) includes a ply layer (20) after two layers of ply fabric are bonded together. The two ends of the two layers of ply fabric overlap in the central area (A1) corresponding to the radial inner, and reinforcing rubber (30) is set on the overlapping ply layer (20) and between the rubber materials in the central area (A1). Reinforcing yarn (31) is sandwiched inside the overlapping ply layer (20). Each longitudinal stripe group (16a) and transverse stripe group (16b) consists of three convex strips as a group. The longitudinal stripe group (16a) is parallel to the tire circumference, and the transverse stripe group (16b) is parallel to the tire axial direction. The longitudinal and transverse stripes are not connected. The cross section of the longitudinal and transverse stripe (16) is defined as triangular or trapezoidal.

2. The pneumatic tire for heavy-duty bicycles according to claim 1, characterized in that: The short groove (12) includes a first short groove (12a) and a second short groove (12b). The first short groove (12a) is located in the central area (A1) near the center line CL of the tread. The second short groove (12b) is located outside the central area (A1) near the edge of the tread (1). Both short grooves (12) are inclined straight grooves, and the direction of the grooves is opposite to the tire driving direction.

3. The pneumatic tire for heavy-duty bicycles according to claim 1, characterized in that: The central zone (A1) unfolded width W2 is limited to 50%-70% of the tread (1) unfolded width W1, and the transverse groove (11a) axial width W3 of the long main groove (11) is designed to be 25%-50% of the central zone (A1) unfolded width W2.

4. A heavy-duty bicycle pneumatic tire according to claim 1, characterized in that: The central tread block (13) is wrench-shaped and is staggered along the tire circumference. The central tread block (13) has a lateral portion and a bent portion, with the bent portion tilting over to the side tread block group (14).

5. A pneumatic tire for heavy-duty bicycles according to claim 1, characterized in that: The side pattern block group (14) consists of a first side pattern block (14a) located in the central area (A1), a second side pattern block (14b) located at the edge of the tread (1), and a third side pattern block (14c). The three pattern blocks of the side pattern block group (14) are quadrilateral.

6. A pneumatic tire for heavy-duty bicycles according to claim 1, characterized in that: The shallow groove (15) is located near the center line CL of the tread and near the edge of the central area (A1). The shallow groove (15) extends on the surface of the central tread block (13) and the first side tread block (14a) in the central area (A1).

7. A pneumatic tire for heavy-duty bicycles according to claim 1, characterized in that: The ribs of the longitudinal rib group (16a) or transverse rib group (16b) in the same group are at the same angle, and the center of gravity of the ribs in the same group is perpendicular to the tread (1).

8. A pneumatic tire for heavy-duty bicycles according to claim 1, characterized in that: The center of gravity of the central ridge of the longitudinal ridge group (16a) or transverse ridge group (16b) in the same group is perpendicular to the tread (1), and the center of gravity of the ridges on both sides is inclined relative to the tread (1) and symmetrically opposite.

9. A pneumatic tire for heavy-duty bicycles according to claim 1, characterized in that: The reinforcing adhesive (30) is composed of a rubber material that resists punctures, and the reinforcing yarn (31) is set to have 1-2 layers.

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