Maintenance-free hollow tire of Y-shaped supporting structure and preparation method of maintenance-free hollow tire

Abstract

The invention discloses a maintenance-free hollow tire of a Y-shaped supporting structure and a preparation method of the maintenance-free hollow tire. The maintenance-free hollow tire of the Y-shaped supporting structure comprises an outer contour, inner holes, a supporting structure, an air inlet hole and a vent hole, the supporting structure is located between the inner holes, the air inlet hole is formed in the top of the hollow tire and communicated with the inner holes, and the vent hole is formed in the portion, between the inner holes, of the supporting structure. By adjusting the size and position of each part of the cavity structure in the hollow tire in the preparation process, good comfort can be kept, and high tire body strength is achieved.

Description

Technical Field

[0001] The invention relates to the field of tire production, in particular to a maintenance-free hollow tire with a Y-shaped support structure and a preparation method thereof. Background Art

[0002] Tires are ground-connected, rolling, elastic rubber products installed on various vehicles and machinery. They bear weight, cushion road impacts, maintain contact with the road, and provide driving and braking forces. Tires are subject to various deformations, loads, forces, and high and low temperature conditions during driving, so they must possess high load-bearing, traction, and cushioning properties.

[0003] In recent years, with the rise of short-distance vehicles like electric bicycles and scooters, and particularly the emergence of shared bikes and electric bikes, tire damage during use can severely impact the user experience and increase maintenance costs. To address tire maintenance issues, most shared bikes and electric bikes use non-pneumatic tires like solid or hollow tires, or use sponge tires instead of inner tubes, ensuring continuous use and maintenance-free operation. To conserve energy, shared bikes and electric bikes require lightweight vehicle components. Therefore, tires must be as lightweight as possible while still ensuring performance meets requirements.

[0004] Solid tires are not accepted by the market due to their poor comfort and heavy weight, although they are durable; the sponge foam inner tube carcass is relatively soft, so it deforms greatly and generates a lot of heat during use. The heat in the center of the inner tube carcass is not easy to dissipate, and the heat accumulation effect will exceed the temperature resistance limit of the material, causing the molecular chain to break, thereby causing tire damage.

[0005] The varying internal structures of hollow tires, including the thickness, shape, and hardness of various materials, significantly impact tire performance. For example, thinner tires offer improved comfort but reduced load-bearing capacity, while higher hardness increases load-bearing capacity but reduces comfort and increases the risk of cracking. Therefore, comprehensive evaluation of all aspects is crucial to developing a product that meets user needs. Summary of the Invention

[0006] The present invention aims to solve the above problems by providing a maintenance-free hollow tire with a Y-shaped support structure and a preparation method thereof. By adjusting the size and position of the hollow cavity inside the hollow tire, good comfort is maintained while having high carcass strength.

[0007] The present invention achieves the above-mentioned purpose through the following technical solutions:

[0008] The present invention provides a maintenance-free hollow tire with a Y-shaped support structure, which includes an outer contour, an inner hole, a support structure, an air inlet hole, and a vent hole. The support structure is located between the inner holes, the air inlet hole is arranged at the top of the hollow tire and is connected to the inner hole, and the vent hole is arranged inside the support structure between the inner holes.

[0009] As a preferred embodiment of the present invention, the hollow tire contains three inner holes, namely one inner hole one and two inner holes two. There is a certain wall thickness between the outer contour and the inner hole to play a supporting role. The support structure formed between the three inner holes inside the hollow tire is Y-shaped, so that the force exerted on the tire can be better transmitted to the rim to avoid tire damage.

[0010] As a preferred embodiment of the present invention, the air inlet is provided at only one position on the circumference; the air vents are provided at only two positions on the circumference, and are symmetrically arranged.

[0011] As a preferred embodiment of the present invention, a represents the total width of the hollow tire, b represents the total height of the cross-section of the hollow tire, and c represents the width of the position where it cooperates with the outer tire and the rim. The specific values of a, b, and c are set according to the specifications of the tire and rim, the customer's requirements for the tire size, etc. The total width a of the hollow tire of the present invention is 30-70 mm, the total height b of the cross-section of the hollow tire is 25-75 mm, and the width c of the position where the outer tire and the rim cooperate is 15-40 mm.

[0012] As a preferred embodiment of the present invention, H1 is the distance from the top of the hollow tire to the top of the inner hole one, H1=5-10%a, H2 is the thickness from the inner wall of the inner hole one to the outer contour of the hollow tire, H2=13-18%a, H3 is the distance from the bottom of the inner hole one to the bottom of the hollow tire, H3=60-70%b, H4 is the thickness from the inner hole two to the outer contour of the hollow tire, H4=10-15%a, H5 is the thickness of the support structure between the two inner holes two, H5=20-30%a, H7 is the thickness of the supporting structure between inner hole one and inner hole two, H7=20-30%a, Re is the radius of the arc connecting the arc one and the arc two in inner hole two, Re≥10mm, Rd is the radius of the arc at the bottom of inner hole two, Rd≥10mm, Rf is the radius of the arc at the top of inner hole two, Rf≥3mm, α is the angle between the arc one in inner hole two and the center line of the hollow tire section, α=5-10°, β is the angle between the arc two in inner hole two and the center line of the hollow tire section, β=30-35°.

[0013] The present invention also provides a method for preparing a maintenance-free hollow tire of a Y-shaped support structure, comprising the following steps:

[0014] Step S1, plasticizing: plasticizing the rubber particles into a fluid rubber material,

[0015] Step S2, extrusion molding: using an extruder with an inner die and an outer die to extrude a long semi-finished tire tube.

[0016] Step S3, cutting and punching: Cut the semi-finished tire tube obtained in step S2 into the set length, and make grooves on the Y-shaped support structure of the cutting surface at both ends, and form ventilation holes after the joints are connected.

[0017] Step S4, bonding: Apply special glue on the cut surface and connect the cut surfaces at both ends to form a ring-shaped semi-finished product with an inner hole.

[0018] Step S5, vulcanization: placing the annular semi-finished product into a mold cavity to obtain a hollow tire.

[0019] As a preferred embodiment of the present invention, the mold in step S5 is provided with a pin hole, and the air intake pin passes through the pin hole on the mold, pierces the sidewall of the hollow tire, and penetrates into any inner hole in the tire tube. Because the rubber material has sealing properties, the inserted pin will not cause air leakage. The pin is a hollow metal tube, which can be inserted through the pin for internal pressure vulcanization molding to obtain a hollow tire. After vulcanization is completed, the pin is removed, leaving an air intake hole on the hollow tire.

[0020] The beneficial effects of the present invention are as follows: through the design of the Y-shaped support structure inside the hollow tire, the hollow tire has the advantages of light weight, good comfort, high load capacity, high speed stability, good durability and the like. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the hollow tire structure of the present invention.

[0022] Figure 2 Schematic diagram of the hollow tire structure corresponding to various parameters of the present invention.

[0023] Figure 3-8 Schematic diagram of the hollow tire structure corresponding to the parameter changes of Examples 1-6.

[0024] Figure 9 Schematic diagram of the hollow tire structure corresponding to the parameters of Example 7.

[0025] In the figure: 1-outer contour, 2-inner hole 1, 3-inner hole 2, 31-arc 1, 32-arc 2, 4-support structure, 5-air inlet, 6-ventilation hole. DETAILED DESCRIPTION

[0026] In order to make the objectives, technical solutions and advantages of the present invention clearer, the implementation method of the present invention will be described in detail below with reference to the accompanying drawings and embodiments, so that the implementation process of how the present invention applies technical means to solve technical problems and achieve technical effects can be fully understood and implemented accordingly.

[0027] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Therefore, the scope of protection of the present invention is not limited to the specific embodiments disclosed below.

[0028] Examples 1-7

[0029] The embodiment of the present invention provides a maintenance-free hollow tire with a Y-shaped support structure, such as Figure 1 As shown, it includes an outer contour 1, an inner hole, a support structure 4, an air inlet 5, and a vent 6. The support structure 4 is located between the inner holes. The air inlet 5 is arranged at the top of the hollow tire and communicates with the inner hole. The vent 6 is arranged inside the support structure 4 between the inner holes.

[0030] As a preferred embodiment of the present invention, the hollow tire contains three inner holes, namely one inner hole 2 and two inner holes 3. There is a certain wall thickness between the outer contour and the inner hole to play a supporting role. The support structure formed between the three inner holes inside the hollow tire is Y-shaped, so that the force exerted on the tire can be better transmitted to the rim to avoid tire damage.

[0031] As a preference of this embodiment, the air inlet 5 is provided at only one position on the circumference; the air vents 6 are provided at only two positions on the circumference, and are symmetrically arranged.

[0032] As a preferred embodiment of this invention, a represents the total width of the hollow tire, b represents the total height of the hollow tire section, and c represents the width at the location where the tire and rim meet. The specific values of a, b, and c are set according to the tire and rim specifications, customer requirements for tire size, etc. In the present invention, the total width a of the hollow tire is 30-70 mm, the total height b of the hollow tire section is 25-75 mm, and the width c at the location where the tire and rim meet is 15-40 mm.

[0033] In Examples 1-7, the total width of the hollow tire a=47 mm, the total cross-sectional height of the hollow tire b=43 mm, and the width of the fitting position of the tire and the rim c=30 mm.

[0034] As attached Figure 2-8As shown, in Example 1, H1 is reduced (H1=2mm), in Example 2, H4 is reduced (H4=3.5mm), in Example 3, H5 and H7 are reduced (H5=8mm and H7=8mm), in Example 4, Re, Rd, and ∠α are reduced (Re=0, Rd=0, ∠α=0), in Example 5, ∠β is increased (∠β=75°), in Example 6, H3 is reduced (H3=23.65mm), and in Example 7, a technical solution of the present invention (H1=4mm, H2=7mm, H3=29.5mm, H4=5.2mm, H5=10mm, H7=12mm, Re=15mm, Rd=10mm, Rf=4mm, ∠α=7°, ∠β=33°). During the test verification, the tire and rim were assembled. Except for the change in the structural dimensions of the hollow tire, the rim and tire remained in the same state during the test verification. The thinning, reduction and enlargement are relative to the size range of the present invention and are not within the size range of the present invention.

[0035] Hollow tire preparation

[0036] The hollow tires of Examples 1-7 are all prepared by a method for preparing a maintenance-free hollow tire with a Y-shaped support structure of the present invention. The method for preparing a maintenance-free hollow tire with a Y-shaped support structure of the present invention comprises the following steps:

[0037] Step S1, plasticizing: plasticizing the rubber particles into a fluid rubber material,

[0038] Step S2, extrusion molding: using an extruder with an inner die and an outer die to extrude a long semi-finished tire tube.

[0039] Step S3, cutting and punching: Cut the semi-finished tire tube obtained in step S2 into the set length, and make grooves on the Y-shaped support structure 4 at both ends of the cutting surface, and form ventilation holes 6 after connecting.

[0040] Step S4, bonding: Apply special glue on the cut surface and connect the cut surfaces at both ends to form a ring-shaped semi-finished product with an inner hole.

[0041] Step S5, vulcanization: placing the annular semi-finished product into a mold cavity to obtain a hollow tire.

[0042] As a preferred embodiment of the present invention, the mold in step S5 is provided with a pin hole. The air intake pin passes through the pin hole on the mold, pierces the sidewall of the hollow tire, and penetrates into any inner hole in the tire tube. Because the rubber material has sealing properties, the inserted pin will not cause air leakage. The pin is a hollow metal tube, which can be inserted into the internal pressure vulcanization molding to obtain a hollow tire. After vulcanization is completed, the pin is removed, leaving the air intake hole 5 on the hollow tire.

[0043] Performance Testing

[0044] The challenge of this invention lies in minimizing tire weight while ensuring performance. Therefore, determining the size, shape, and relative positioning of various components is crucial, ultimately requiring compliance with relevant testing. Considering the complex operating environment of shared bikes, the test conditions were based on ISO 4210-7, Bicycles – Safety requirements for bicycles – Part 7, and stricter customer requirements. The tire must remain stable even after more than one million collisions with obstacles.

[0045] Tire loads are set based on tire specifications, for example, radial wheel load (bicycles: front / rear wheels * 64kg; e-bikes: front wheel * 75kg, rear wheel * 100kg). The test roller diameter is 760 ± 10mm. The obstacle blocks are 50mm ± 2.5mm wide and 10mm ± 0.25mm thick, with a 45-degree chamfer at mid-thickness. The distance between the centerlines of adjacent obstacle blocks along the roller circumference is approximately 400mm, not exceeding 420mm. The roller is rotated at a linear speed of 25 km / h (±10%), striking the obstacle blocks for a specified period of time to achieve one million impacts between the tire and the obstacle. No damage to the inner or outer tire is permitted after the test. The tire and wheel hub are marked with a line, ensuring that relative displacement does not exceed 50mm after the test.

[0046] The test results are shown in Table 1 below

[0047] Plan No. Changes relative to the present invention Test results Result determination Solution 1 H1 Thinning The inner and outer tires are not damaged, and the displacement is 63mm. Failed the test Option 2 H4 Thinning The inner tube cracked after the obstacle course was hit 830,000 times Failed the test Option 3 H5, H7 thinning The inner tube cracked after the obstacle block was hit 680,000 times Failed the test Option 4 Re, Rd, ∠α decrease The inner tube cracked after the obstacle block was used 550,000 times Failed the test Option 5 ∠β increases The inner tube cracked after the obstacle block was hit 760,000 times Failed the test Option 6 H3 decreases The inner tube cracked after the obstacle block was used 800,000 times Failed the test Option 7 Structure and size of the present invention The inner and outer tires remained intact after hitting the obstacle block 1 million times Pass the test

[0048] Table 1 Summary of test results of Examples 1-7

[0049] As can be seen from Table 1, when the dimensions of various components fall below the specified ranges according to the present invention, the tire's performance deteriorates, failing performance tests and, therefore, failing to meet performance requirements. When the dimensions exceed these ranges, the tire becomes heavier, and the hollow tire tends to become more solid, reducing comfort and failing to meet the original intent of the present invention. Furthermore, thinning H1 can cause relative displacement between the tire and the wheel hub. This is because the sidewall is too thin and lacks strength, resulting in a loose fit between the tire and the rim. Therefore, thinning H2 also results in a thin sidewall that is too thin and lacks strength, resulting in a loose fit between the tire and the rim, leading to relative displacement between the tire and the wheel hub.

[0050] Reducing Re and Rd reduces the curvature of the support structure transition zone. While this reduces weight, it also leads to stress concentration, which can degrade the tire's performance during testing, causing it to fail the test and therefore fail to meet performance requirements. The same problem occurs when Rf is reduced.

[0051] A decrease in H3 will result in a decrease in the strength of the hollow tire's support structure, which will cause it to fail the performance test.

[0052] Although the present invention is described herein with reference to illustrative embodiments of the present invention, the above embodiments are merely preferred embodiments of the present invention, and the embodiments of the present invention are not limited to the above embodiments. It should be understood that those skilled in the art can design many other modifications and implementations, which will fall within the scope and spirit of the principles disclosed in this application.

Claims

1. A maintenance-free hollow tire with a Y-shaped support structure, characterized by: The hollow tire comprises an outer contour (1), an inner hole, a support structure (4), an air inlet (5), and a vent (6), wherein the support structure (4) is located between the inner holes, the air inlet (5) is arranged at the top of the hollow tire and communicates with the inner hole, and the vent (6) is arranged inside the support structure (4) between the inner holes.

2. A maintenance-free hollow tire with a Y-shaped support structure according to claim 1, characterized in that: There are three inner holes, namely one inner hole one (2) and two inner holes two (3), and the support structure (4) formed between the three inner holes is Y-shaped.

3. A maintenance-free hollow tire with a Y-shaped support structure according to claim 1 or 2, characterized in that: The air inlet (5) is provided at only one location on the circumference; and the air vent (6) is provided at only two locations on the circumference.

4. A maintenance-free hollow tire with a Y-shaped support structure according to claim 3, characterized in that: The vent holes (6) are arranged symmetrically on the circumference.

5. A maintenance-free hollow tire with a Y-shaped support structure according to claim 4, characterized in that: The total width a of the hollow tire is 30-70 mm, the total section height b of the hollow tire is 25-75 mm, and the width c of the matching position of the outer tire and the rim is 15-40 mm.

6. A maintenance-free hollow tire with a Y-shaped support structure according to claim 5, characterized in that: The distance from the top of the hollow tire to the top of the inner hole (2) is H1 = 5-10% a, the thickness from the inner wall of the inner hole (2) to the outer contour of the hollow tire is H2 = 13-18% a, the distance from the bottom of the inner hole (2) to the bottom of the hollow tire is H3 = 60-70% b, the thickness from the inner hole (3) to the outer contour of the hollow tire is H4 = 10-15% a, the thickness of the support structure (4) between the two inner holes (3) is H5 = 20-30% a, the support structure (4) between the inner hole (2) and the inner hole (3) is H6 = 20-30% a. ) has a thickness H7=20-30%a, the radius of the arc between the arc 1 and the arc 2 (32) in the inner hole 2 (3) is Re≥10mm, the radius of the arc at the bottom of the inner hole 2 (3) is Rd≥10mm, the radius of the arc at the top of the inner hole 2 (3) is Rf≥3mm, the angle α between the arc 1 (31) in the inner hole 2 (3) and the center line of the hollow tire section is 5-10°, and the angle β between the arc 2 (32) in the inner hole 2 (3) and the center line of the hollow tire section is 30-35°.

7. A maintenance-free hollow tire with a Y-shaped support structure according to claim 6, characterized in that: a=47mm, b=43mm, c=30mm, H1=4mm, H2=7mm, H3=29.5mm, H4=5.2mm, H5=10mm, H7=12mm, Re=15mm, Rd=10mm, Rf=4mm, ∠α=7°, ∠β=33°.

8. A method for preparing a maintenance-free hollow tire with a Y-shaped support structure, comprising the following steps: Step S1, plasticizing: plasticizing the rubber particles into a fluid rubber material. Step S2, extrusion molding: using an extruder with an inner die and an outer die to extrude a long semi-finished tire tube. Step S3, cutting and punching: cutting the long semi-finished tire tube obtained in step S2 to a set length and processing the ventilation holes (6). Step S4, bonding: Apply special glue on the cut surface and connect the cut surfaces at both ends to form a ring-shaped semi-finished product with an inner hole. Step S5, vulcanization: placing the annular semi-finished product into a mold cavity to obtain a maintenance-free hollow tire with a Y-shaped support structure.

9. The method for preparing a maintenance-free hollow tire with a Y-shaped support structure according to claim 8, characterized in that: The step S3 of machining the vent hole (6) specifically includes machining grooves on the Y-shaped support structure (4) at both ends of the cutting surface, and then forming the vent hole (6) after connecting them.

10. The method for preparing a maintenance-free hollow tire of a Y-shaped support structure according to claim 8 or 9, characterized in that: In step S5, the mold is provided with a pin hole. The air intake pin passes through the pin hole on the mold, pierces the hollow tire wall, and penetrates into any inner hole in the tire tube. Because the rubber material has sealing properties, the inserted pin will not cause air leakage. The pin is a hollow metal tube, which can be inserted into the internal pressure vulcanization molding through the pin to obtain a hollow tire. After the vulcanization is completed, the pin is removed, and the air intake hole (5) is left on the hollow tire.

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