Agricultural radial tire structure capable of preventing shoulder separation and delamination

Abstract

The utility model provides a kind of agricultural meridian tire structure of preventing shoulder empty, delamination, it is related to agricultural tire manufacturing technical field, including carcass layer and tread, adhesive film, pad rubber, first transition adhesive film, belt member, second transition adhesive film are sequentially set on carcass layer, the lap area of pad rubber and belt member is located in the end of belt member, the section of pad rubber is trapezoidal, has E, F, G, H four end points, the horizontal distance g of inner end point E from shoulder point P is 150mm-200mm, the difference level e of inner end point E and the outermost end point A of belt member is 40-80mm, F point is located within the outermost end point A of belt layer, limit the positional relationship of pad rubber and the end of belt member, ensure that the end of belt member keeps horizontal state, eliminate the sharp stress concentration point caused by the end of belt layer "upward" or "sag", ensure that the deformation of belt layer is stable in the process of tire use, stress is more uniform, improve tire durability, solve the problem of shoulder empty, delamination.

Description

Technical Field

[0001] This utility model relates to the field of agricultural tire manufacturing technology, specifically to an agricultural radial tire structure that prevents shoulder gaps and delamination. Background Technology

[0002] China's annual tire production target for 2025 is 704 million units, with a radialization rate of 96%. Of these, 12 million will be agricultural tires, with a radialization rate of 16%. Currently, the European tractor original equipment tire market is mainly dominated by foreign manufacturers such as MICHELIN, Trelleborg, Mitas, Alliance, and BKT. The vast majority of agricultural tires produced by Chinese brands are still bias-ply tires, with a radialization rate of less than 5%.

[0003] Agricultural tires include tractor tires, combine harvester tires, agricultural truck tires, forestry tires, etc. The requirements for different types of agricultural tires vary depending on the vehicle's operating environment, as shown in the table below: The following requirements apply to tractor tires: 1. Low soil compaction under low air pressure; 2. Puncture resistance; 3. High-speed performance; 4. Low cost. Traditional tractor tires use bias-ply tires, resulting in severe homogenization and copying, and numerous issues such as shoulder gaps and delamination. These tires fail to meet customer needs and product development has reached a bottleneck. Agricultural Meridian products, which address these issues, represent the future direction of development. Utility Model Content

[0004] The technical problem to be solved by this utility model is that existing tractor agricultural tires are prone to shoulder gaps and delamination. In order to solve the above problems, an agricultural radial tire belt layer structure is provided.

[0005] This utility model is achieved in the following manner: An agricultural radial tire structure for preventing shoulder gaps and delamination includes a carcass layer at the bottom and a tread layer at the top. The carcass layer is sequentially provided with an adhesive film, a gasket, a first transition film, a belt layer component, and a second transition film. The overlap area between the gasket and the belt layer component is located at the end of the belt layer component. The gasket has a trapezoidal cross-section, forming four endpoints: E, F, G, and H. The horizontal distance g between the inner endpoint E of the gasket and the shoulder point P is 150mm-200mm. The difference e between the inner endpoint E of the gasket and the outermost endpoint A of the belt layer component is 40-80mm, and the gasket's F point is located inside the outermost endpoint A of the belt layer.

[0006] Preferably, the padding is a thin-edged film with one side, and the horizontal distance between points EF is greater than the horizontal distance between points GH.

[0007] Preferably, the difference between the endpoint C of the first transition film and the outermost endpoint A of the belt layer component is 15~20mm, the difference between the endpoint D of the second transition film and the outermost endpoint A of the belt layer component is 30~50mm, the adhesive film is symmetrically arranged on both sides along the center line of the belt layer width direction, and the adhesive film is located below the padding adhesive.

[0008] Preferably, the rubber pad is provided separately or the rubber pad and the tire sidewall rubber form an integral structure.

[0009] Preferably, the thickness of the first transition film and the second transition film is 2-3 mm.

[0010] Preferably, the thickness of the adhesive film is 1.2~1.8mm.

[0011] Preferably, the belt layer component is composed of a first belt layer, a second belt layer, a third belt layer, a fourth belt layer, a fifth belt layer, and a sixth belt layer stacked from bottom to top. Odd-numbered belt layers are wide belt layers, and even-numbered belt layers are narrow belt layers. The difference 'a' between the same-side endpoints of adjacent belt layers is 20-25 mm. The cord angle between the first and second belt layers is 60°-63°, the cord angle between the third and fourth belt layers is 64°-66°, and the cord angle between the fifth and sixth belt layers is 68°-70°. The cord angles of the odd-numbered and even-numbered belt layers are opposite in direction.

[0012] Preferably, the first belt layer and the second belt layer have the same cord angle, the third belt layer and the fourth belt layer have the same cord angle, and the fifth belt layer and the sixth belt layer have the same cord angle.

[0013] Preferably, the cords in the belt layer are polyester cords.

[0014] Compared to existing technologies, this invention provides a gasket between the belt layer component and the tire carcass, which limits the positional relationship between the gasket and the end of the belt layer component. This ensures that the end of the belt layer component remains horizontal, eliminates sharp stress concentration points caused by the "upward" or "downward" tilt of the belt layer end, ensures stable deformation of the belt layer during tire use, more uniform stress distribution, improves tire durability, and solves the problems of shoulder gaps and delamination. Attached Figure Description

[0015] Figure 1 This is a structural schematic diagram of one embodiment of the present invention.

[0016] Figure 2 This is a schematic diagram of the tire cross-section in one embodiment of the present invention.

[0017] Figure 3 This is a schematic diagram of another embodiment of the present invention.

[0018] Figure 4 This is a schematic diagram of the ground contact mark of the tire of this utility model.

[0019] Among them, 1 is the adhesive film; 2 is the gasket; 3 is the first transition film; 4 is the first belt layer; 5 is the second belt layer; 6 is the third belt layer; 7 is the fourth belt layer; 8 is the fifth belt layer; 9 is the sixth belt layer; 10 is the second transition film; 11 is the tread; 12 is the sidewall rubber; 13 is the bead protector; and 14 is the bead wrap. Detailed Implementation

[0020] The present invention will be further described below with reference to specific embodiments, and the advantages and features of the present invention will become clearer with the description. However, unless otherwise specified, the specific experimental methods involved in the following embodiments are conventional methods or implemented according to the conditions recommended in the manufacturer's instructions.

[0021] See Figures 1-4 ,in Figures 1-3 All are part of a symmetrical diagram, with the other side symmetrical to it. An agricultural radial tire structure for preventing shoulder gaps and delamination includes a carcass layer at the bottom and a tread layer at the top. The carcass layer is sequentially arranged with an adhesive sheet 1, a gasket 2, a first transition sheet 3, a belt layer component, and a second transition sheet 10. The tread 11 is positioned above the second transition sheet 10. If the ends of the belt layer tilt upwards or downwards, it will cause the belt layer edges to become unraveled, resulting in uneven distribution and varying density of the cords. This can lead to separation between cords and between cords and the rubber compound, generating heat during operation and causing shoulder gaps. To prevent shoulder gaps, a gasket 2 is placed below the first transition sheet 3 to ensure the ends of the belt layer component are horizontal. The overlap area between the gasket 2 and the belt layer component is located at the end of the belt layer component, i.e., the tire shoulder area. The cross-section of the gasket 2 is trapezoidal, forming four sections: E, F, G, and H. The endpoints are defined as follows: EH is the lower base of the trapezoid, FG is the upper base of the trapezoid, and EF and HG are the two sides of the trapezoid. The horizontal distance g between the inner endpoint E of the pad 2 and the tire shoulder point P is 150mm-200mm. The tire shoulder point P is the intersection of the running surface arc and the sidewall arc on the tire cross-section. The difference e between the inner endpoint E of the pad 2 and the outermost endpoint A of the belt layer is 40-80mm. The F point of the pad 2 is located inside the outermost endpoint A of the belt layer. At the same time, the horizontal distance between the two points EF is greater than the horizontal distance between the two points GH, forming a single-sided thin-edge rubber sheet. That is, the cross-section of the pad 2 is an isosceles trapezoid. In the formed agricultural radial tire, the plane between the EF of the pad is bonded to the first transition rubber sheet 3, and the plane between the EH of the pad is bonded to the tire body through the adhesive sheet. The pad 2 is set between the first transition rubber sheet 3 and the tire body, so that the endpoints of the belt layer are set horizontally.

[0022] The gasket 2 needs to be matched with the belt layer component. Its thickness, width, and position can be adjusted as needed to suit tires of different sizes. The gasket 2 has different thickness requirements in different series: 85 series can be 16mm, 25mm, or 35mm; 65 series can be 20mm or 30mm; and 70 series can be 28mm or 40mm. The thickness of the gasket 2 refers to the vertical distance between the endpoints EF.

[0023] The centerline of the first transition film 3 in the width direction coincides with the circumferential center plane of the tire. The difference c between the endpoint C of the first transition film 3 and the endpoint A on the same side of the second belt layer 5 is 15~20mm, that is, the horizontal distance c between the endpoint C of the first transition film 3 and the endpoint A of the second belt layer 5 is . The first transition film 3 is located between the gasket and the belt layer components, and is used to bond and fix the gasket and the belt layer components to prevent delamination. The first transition film 3 also plays a role in isolation, preventing the gasket from seeping into the belt layer components and damaging the bonding force between the belt layer overlay and the polyester cord, making the structure of the belt layer less susceptible to damage and preventing cracking at the endpoints of the belt layer during long-term tire use. The first transition film uses a low-heat-generating rubber compound to improve tire durability.

[0024] The centerline of the second transition film 10 in the width direction coincides with the circumferential center plane of the tire. The difference d between the end point D of the second transition film 10 and the end point A on the same side of the second belt layer 5 is 30~50mm, that is, the horizontal distance between the end point D of the second transition film 10 and the end point A of the second belt layer 5 is d. The second transition film 10 is located between the belt layer component and the tread and is used to bond and fix the belt layer component and the tread to avoid delamination.

[0025] The adhesive film 1 is symmetrically arranged along the centerline of the belt layer width direction. The adhesive film 1 is located below the padding rubber. The difference f between the outer end point K of the adhesive film 1 and the end point B of the first belt layer 4 is 20mm-40mm. The adhesive film firmly bonds the padding rubber to the tire carcass, preventing shoulder gaps. In addition, the adhesive film is located at the end of the belt layer, which also serves to fill the gaps. Combined with the end difference of the belt layer, it helps to relieve end stress.

[0026] Furthermore, the pad 2 can be configured in two ways: one is that the pad 2 and the sidewall rubber 12 form an integral structure, and the other is that the pad 2 is configured separately; for example... Figures 1-2 As shown, the padding adhesive 2 and the sidewall adhesive 12 form an integrated structure to create a crown-covering side structure, resulting in high molding efficiency and simple operation. The difference b between the outer end point K of the adhesive film 1 and the end point C of the first transition film 3 is 15~20mm.

[0027] like Figure 3As shown, the pad 2 is set separately from the sidewall rubber 12, forming a sidewall crown structure, which can improve the sidewall flexibility; the sidewall width can be reduced by 8-10mm, improving tire uniformity; the semi-finished product is fuller, and the dynamic balance performance is better; the molding complexity is reduced; the pad flexural deformation at the tire shoulder area is reduced, and heat generation is reduced. The outer end point of the adhesive sheet 1 is located outside the end point C of the first transition sheet 3.

[0028] The lower end point I of the sidewall rubber 12 is located at the rim lug, which is the contact area between the rim flange and the bead protector.

[0029] Furthermore, the thickness of both the first transition film 3 and the second transition film 10 is 2~3mm, preferably 2.5mm. The second transition film 10 is wider than the first transition film 3, and the difference between their endpoints is 10~20mm.

[0030] In one embodiment, depending on the tire size, the width of the second transition film 10 is 550 mm or 750 mm, and correspondingly, the width of the first transition film is 530 mm or 730 mm.

[0031] Furthermore, the thickness of the adhesive film 1 is 1.2~1.8mm, preferably 1.5mm, and the width of the adhesive film 1 is 150mm, 250mm or 350mm depending on the size of the tire.

[0032] The belt layer component is composed of, from bottom to top, a first belt layer 4, a second belt layer 5, a third belt layer 6, a fourth belt layer 7, a fifth belt layer 8, and a sixth belt layer 9 stacked together. Odd-numbered belt layers are wide belt layers, and even-numbered belt layers are narrow belt layers. The difference 'a' between the endpoints on the same side of adjacent belt layers is 20-25 mm. Specifically, the belt layer component is composed of alternating narrow and wide belt layers. The centerline of each belt layer in the width direction coincides with the circumferential center plane of the tire. The belt layers in odd-numbered layers have equal widths, and the belt layers in even-numbered layers have equal widths. Furthermore, the belt layers in odd-numbered layers are all wider than those in even-numbered layers. The first belt layer 4, the third belt layer 6... The fifth belt layer 8 is a wide belt layer, with its endpoint on the same side being point A. The second belt layer 5, the fourth belt layer 7, and the sixth belt layer 9 are narrow belt layers, with their endpoints on the same side being point B. The horizontal distance between the endpoints A and B of adjacent wide and narrow belt layers on the same side is the difference 'a' between the endpoints on the same side of adjacent belt layers, which is 20~25mm. The difference between belt layers can disperse end stress, prevent cord breakage, reduce interlayer shear stress, and prevent delamination. The wide belt layer covers the end of the narrow belt layer, forming a physical barrier, inhibiting crack propagation, and reducing the risk of delamination in the tire shoulder area. The alternating arrangement of wide and narrow belt layers reduces pressure fluctuations in the grounding area and avoids uneven grounding pressure distribution, which can cause localized wear. The cord angle between the first belt layer 4 and the second belt layer 5 is 60°-63°, the cord angle between the third belt layer 6 and the fourth belt layer 7 is 64°-66°, and the cord angle between the fifth belt layer 8 and the sixth belt layer 9 is 68°-70°. The cord angles of the odd-numbered and even-numbered belt layers are opposite. The cord angle refers to the angle between the cord in each polyester ply and the circumferential line of the crown. The cords of adjacent belt layers extend in opposite directions: specifically, the cords of the first belt layer 4, the third belt layer 6, and the fifth belt layer 8 extend to the right, while the cords of the second belt layer 5, the fourth belt layer 7, and the sixth belt layer 9 extend to the left. The cord extension direction of the belt layers must follow the direction of the tire carcass cords. The setting of the belt layer cord angles ensures that the tire's contact patch is elliptical (close to rectangular), improving the continuity of the tread pattern and reducing soil compaction. Figure 4 As shown, a finite element analysis was performed on a tire with the belt layer structure of this utility model. Under the conditions of air pressure of 160 kPa and load of 1950 kg, the tire's ground contact mark is elliptical with clear edges.

[0033] Furthermore, the first belt layer 4 and the second belt layer 5 have the same cord angle, the third belt layer 6 and the fourth belt layer 7 have the same cord angle, and the fifth belt layer 8 and the sixth belt layer 9 have the same cord angle. Specifically, the cord angles of the first belt layer 4 and the second belt layer 5 are 60°, 61°, 62°, or 63°; the cord angles of the third belt layer 6 and the fourth belt layer 7 are 64°, 65°, or 66°; and the cord angles of the fifth belt layer 8 and the sixth belt layer 9 are 68°, 69°, or 70°. The symmetrical and consistent angles of the belt layers ensure a uniform stress distribution and good durability, further guaranteeing that the tire contact patch is elliptical (close to rectangular).

[0034] A first transition film is used to transition the gasket and belt layer components at the overall junction area to improve adhesion.

[0035] In this invention, the first belt layer to the sixth belt layer are all made of polyester cord calendering and coating; the adhesive film, the first transition film 3, and the second transition film 10 are all calendered by a composite extruder; and the padding adhesive 2 is extruded by an extrusion extruder.

[0036] This utility model of agricultural radial tire uses a 6-layer polyester cord belt layer, which, compared to the traditional nylon buffer layer, can ensure greater load capacity and enhance the load-bearing capacity of agricultural tires. The belt layer uses polyester, with a suitable cutting angle and elongation coefficient, which minimizes cross-sectional width expansion while ensuring the outer diameter of the product, thus improving the thermal shrinkage of the agricultural tire cord. The 6-layer cross-belt layer structure ensures that the product imprint is rectangular, improving the continuity of the product pattern and reducing soil compaction. Low heat-generating rubber is added between the tire body and the belt layer. Adhesive sheets are added to the belt layer and the tread to improve adhesion and increase the service life of agricultural tires.

[0037] Therefore, this invention employs a suitable gasket placed between the belt layer and the tire carcass to reduce the curvature of the belt layer component, ensuring that the ends of the belt layer neither curl upwards nor sag downwards. This guarantees the parallelism of the belt layer component ends, eliminating sharp stress concentration points caused by "curving upwards" or "sags," ensuring stable deformation of the belt layer during tire use, more uniform stress distribution, and improved tire durability. Furthermore, the gasket uses a low-heat-generating material to reduce heat generation.

[0038] The above description is only a preferred embodiment of the present utility model. It should be noted that those skilled in the art can make several changes and improvements without departing from the overall concept of the present utility model, and these should also be considered within the protection scope of the present utility model.

Claims

1. An agricultural radial tire structure for preventing shoulder gaps and delamination, comprising a lowermost carcass layer and an uppermost tread layer, characterized in that, The carcass layer is sequentially provided with an adhesive film (1), a pad (2), a first transition film (3), a belt layer component, and a second transition film (10). The overlap area between the pad (2) and the belt layer component is located at the end of the belt layer component. The cross section of the pad (2) is trapezoidal, forming four endpoints: E, F, G, and H. The horizontal distance g between the inner endpoint E of the pad (2) and the shoulder point P is 150mm-200mm. The difference e between the inner endpoint E of the pad (2) and the outermost endpoint A of the belt layer component is 40-80mm. The F point of the pad (2) is located inside the outermost endpoint A of the belt layer.

2. The agricultural radial tire structure for preventing shoulder gaps and delamination according to claim 1, characterized in that, The padding adhesive (2) is a thin-edged film on one side, and the horizontal distance between points EF is greater than the horizontal distance between points GH.

3. The agricultural radial tire structure for preventing shoulder gaps and delamination according to claim 2, characterized in that, The difference between the end point C of the first transition film (3) and the outermost end point A of the belt layer component is 15~20mm, and the difference between the end point D of the second transition film (10) and the outermost end point A of the belt layer component is 30~50mm. The adhesive film (1) is symmetrically arranged on the left and right sides along the center line of the belt layer width direction. The adhesive film (1) is located below the padding adhesive (2).

4. The agricultural radial tire structure for preventing shoulder gaps and delamination according to claim 3, characterized in that, The padding rubber (2) is set separately or the padding rubber (2) and the sidewall rubber (12) form an integral structure.

5. The agricultural radial tire structure for preventing shoulder gaps and delamination according to claim 4, characterized in that, The thickness of the first transition film (3) and the second transition film (10) is 2~3mm.

6. The agricultural radial tire structure for preventing shoulder gaps and delamination according to claim 5, characterized in that, The thickness of the adhesive film (1) is 1.2~1.8mm.

7. The agricultural radial tire structure for preventing shoulder gaps and delamination according to claim 6, characterized in that, The belt layer component is composed of a first belt layer (4), a second belt layer (5), a third belt layer (6), a fourth belt layer (7), a fifth belt layer (8), and a sixth belt layer (9) stacked from bottom to top. Among them, the odd-numbered belt layers are wide belt layers, and the even-numbered belt layers are narrow belt layers. The difference 'a' between the same-side endpoints of adjacent belt layers is 20~25mm. The cord angle between the first belt layer (4) and the second belt layer (5) is 60°-63°, the cord angle between the third belt layer (6) and the fourth belt layer (7) is 64°-66°, and the cord angle between the fifth belt layer (8) and the sixth belt layer (9) is 68°-70°. The cord angles of the odd-numbered belt layers and the even-numbered belt layers are opposite in direction.

8. The agricultural radial tire structure for preventing shoulder gaps and delamination according to claim 7, characterized in that, The first belt layer (4) and the second belt layer (5) have the same cord angle, the third belt layer (6) and the fourth belt layer (7) have the same cord angle, and the fifth belt layer (8) and the sixth belt layer (9) have the same cord angle.

9. The agricultural radial tire structure for preventing shoulder gaps and delamination according to claim 8, characterized in that, The cords in the belt layer are polyester cords.

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