A heavy-duty radial tire with a jointless braided multi-layer wound belt structure

Abstract

This application belongs to the field of heavy-duty and low-profile tires, and particularly relates to a heavy-duty radial tire with a jointless braided multi-layer winding belt structure. The tire includes a tread, a belt layer, a carcass, a sidewall, and a bead. The belt layer includes a No. 1 belt layer, a C-shaped belt layer, a No. 2 belt layer, and a No. 3 belt layer. The C-shaped belt layer is arranged above the No. 1 belt layer, and the No. 2 belt layer is attached to the C-shaped belt layer. The C-shaped belt layer uses a single cord fabric strip to start from the middle of the tread and wind towards one end point of the belt layer. After reaching the end point, it turns and winds to the other end point, and thus performs reciprocating multi-layer winding at each turning point of the winding layer. After the winding is completed, it returns to the starting position. This application ensures the strength of the tire, so that in the case of heavy loads, this structure can also effectively suppress the circumferential deformation of the tire. At the same time, the durability, high-speed performance, load capacity, and handling performance of the tire are improved.

Description

Technical Field

[0001] This application belongs to the field of heavy-duty and low-profile tires, and particularly relates to a heavy-duty radial tire with a jointless braided multi-layer winding belt structure. Background Art

[0002] With the development of the automotive industry, urban roads, and highways, the operating environment has put forward higher requirements for tire performance. Especially for heavy-duty and low-profile all-steel radial tires, the operating environment they face is more severe. It is also precisely with the introduction of policies in the automotive field and the change of vehicle models that the development of low-profile load tires has become faster and has gradually become the mainstream of the market.

[0003] The structure of all-steel radial load tires is generally a four-layer belt structure or a zero-degree belt structure. The belt layers are radially arranged between the carcass and the tread and are the main load-bearing components of the tire. The belt layers are in a cross structure and form a certain angle with the center of the tread. When the tire of this structure is inflated and under load during driving, the hoop effect of the belt layer in the shoulder area on the tire is less than that in the middle area of the tread. Therefore, during tire driving, the radial expansion amount in the shoulder area of the tire is larger than that in the middle area of the tire. Especially in the structure of heavy-duty and low-profile tires, due to the relatively wide tread of the tire during driving, the radial expansion of the shoulder part is relatively larger, resulting in a relatively larger circumferential deformation of the shoulder part of the tire during driving, causing higher heat generation at the shoulder position and prone to problems such as delamination or cracking between the belt layer and the tread rubber.

[0004] In order to suppress the circumferential deformation of the tire during use, Chinese Patent CN206733966U discloses a structure that combines zigzag winding and parallel spiral winding. The belt structure of this tire is successively laminated with a first belt layer and a second belt layer on the carcass, and then a zigzag winding is performed on the second belt layer, and a spiral winding is performed on the zigzag winding layer. This structure can effectively restrain the radial expansion of the wheel during use. However, due to the excessive variety of steel wire materials, the heat generation at the crown of the tire is relatively large, and the weight of the tire increases significantly, increasing the cost.

[0005] Chinese Patent CN208698373U discloses a folded multi-layer winding belt structure. The belt structure of this tire is successively laminated with a first belt layer and a second belt layer on the carcass, and a folded multi-layer winding is performed on the second belt layer, especially with four layers of winding on the shoulder. Then, a third belt layer is laminated on the wound belt layer. This structure can effectively solve the problem of large deformation in the shoulder area of the tire. However, due to a large amount of steel wire material at the shoulder position, the heat generation in the shoulder area of the tire is relatively large, ultimately resulting in premature damage to the shoulder position of the tire due to excessive heat generation.

[0006] Chinese Patent CN108407551A discloses a structure using a single steel wire or multiple steel wires wound side by side. In this tire belt layer structure, a first belt layer, a zero-degree side-by-side winding layer, and a second belt layer are sequentially laminated on the carcass. This structure can inhibit the circumferential deformation of the tire and improve the shape of the tire's ground contact patch. However, since the steel wire material in this structure is equivalent to only three belt layers, the structure is not very strong and can only be limited to tires with relatively low loads. If it is used for low-profile tires with high loads, this structure cannot effectively inhibit the circumferential deformation of the tire. Summary of the Invention

[0007] In view of the above problems, the present application provides a heavy-duty radial tire with a jointless braided multi-layer wound belt layer structure. Its belt layer structure consists of traditional strip-shaped Belt Layers 1#, 2#, 3# and a jointless braided multi-layer wound belt layer, namely the "C-shaped structure" belt layer. This structure can effectively restrain the circumferential deformation of the tire during use, optimize the stress distribution of the belt layer, make the tire force more evenly distributed, and inhibit the deformation of the tire shoulder after being stressed. The more uniform force distribution of the tire can reduce the heat generation in the crown area and reduce the probability of delamination and tearing. The belt layer structure includes Belt Layers 1#, 2#, 3# and a wound belt layer, ensuring the strength of the tire, so that in the case of heavy loads, this structure can still effectively inhibit the circumferential deformation of the tire. At the same time, the durability, high-speed performance, load capacity, and handling performance of the tire are improved.

[0008] To achieve the above objectives, the present application adopts the following technical solutions:

[0009] A heavy-duty radial tire with a jointless braided multi-layer wound belt layer structure. The tire includes a tread, a belt layer, a carcass, a sidewall, and a bead. The belt layer includes Belt Layer 1#, Belt Layer 2#, and Belt Layer 3#. Belt Layer 1# is laminated on the carcass and is the innermost radially. Belt Layer 3# is laminated on top of Belt Layer 2#, and the belt layer also includes a C-shaped structure belt layer. The C-shaped structure belt layer is arranged on top of Belt Layer 1#, and Belt Layer 2# is laminated on top of the C-shaped structure belt layer. The C-shaped structure belt layer uses a single cord fabric strip to start from the middle of the tread and wind towards one end point of the belt layer. After reaching the end point, it turns and winds to the other end point, and thus performs reciprocating multi-layer winding at each turning point position of the winding layer. After the winding is completed, it returns to the starting position.

[0010] As a further improvement, the width of the C-shaped structure belt layer in the present application is wider than the width of Belt Layer 1# and narrower than the width of Belt Layer 2#. Belt Layer 3# is narrower than the width of Belt Layer 2#. Specifically, the width of the C-shaped structure belt layer is 10-20 mm wider than the width of Belt Layer 1# and 20-30 mm narrower than the width of Belt Layer 2#. Belt Layer 3# is 30-70 mm narrower than the width of Belt Layer 2#.

[0011] As a further improvement, the cord angle of the 1# belt layer is 10-60° with respect to the circumferential direction; the cord angle of the 2# belt layer is 10-60° with respect to the circumferential direction, and the direction is opposite to that of the 1# belt layer; the cord angle of the 3# belt layer is 10-60° with respect to the circumferential direction, and the direction is the same as that of the 2# belt layer.

[0012] As a further improvement, the number of layers of the C-shaped belt layer is 2W layers, where W is a non-zero natural number. Every 2 layers form a group, and the total number of layers is 2 or a multiple of 2.

[0013] As a further improvement, the starting point of the braiding and winding of the C-shaped belt layer is preferably the center of the tread, and the end point returns to the starting position. The designed width of the C-shaped belt layer is B. On the circumferences on both sides of B / 2 and -B / 2 positioned on the belt forming drum, a plurality of turning points are respectively arranged. The winding circumference of the C-shaped belt layer in this application is designed overall considering the load of the tire, the shoulder tension, the width of the C-shaped belt layer, and the stretching performance of other belt layers.

[0014] As a further improvement, the number of layers of the 1# belt layer, 2# belt layer, and 3# belt layer can be increased or decreased by 1 to 2 layers.

[0015] As a further improvement, the designed width of the C-shaped belt layer is B, and the single-turn winding width is T.

[0016] T = cord strip width t + winding gap (including winding angle);

[0017] The number of spiral turns required for the cord strip to travel the width B of the C-shaped belt layer from one turning point to the next turning point is n, where n ∈ 1, 2, 3, 4, 5, 6… Then the number of single-layer winding turns of the cord strip N = B / T, the number of turning points on one side a = N / n, and the turning points on both sides should be evenly staggered.

[0018] As a further improvement, the designed width B of the C-shaped belt layer is 240 mm, the single-turn winding width T is 10 mm, and the number of single-layer winding turns of the cord strip N = B / T = 24; the number of spiral turns n required for the cord strip to travel the width B of the C-shaped belt layer is 4, and the number of turning points a on each side = N / n = 24 / 4 = 6. The turning points on both sides are evenly staggered in terms of angle; the winding method is that a single cord strip starts from the center point O of the tread (positioned at 0), winds through 4*49 / 48*360° to reach a turning point A on one side (positioned at: 120) and then turns; when it winds through 2*4*49 / 48*360°, it reaches the turning point C on the other side (positioned at: -120); it winds back and forth in multiple layers between the two shoulders in the same way, and returns to the center point O after the winding ends.

[0019] As a further improvement, the cord fabric strip of the C-shaped belt layer is made by calendering or extrusion of several steel cord plies. The width and thickness of the cord fabric strip can be determined according to actual design requirements, and the surface is coated with rubber. The width, density, number of cord plies and thickness of the cord fabric strip are determined according to the design requirements. As a further improvement, the number of cord plies of the cord fabric strip of the C-shaped belt layer is preferably 3 to 9, and the width is preferably 5 to 20 mm. If the number of cord plies is too small and the cord fabric strip is narrow, the total number of winding turns is large, which affects the production efficiency; if the number of cord plies is large, the cord fabric strip is wide and the length of the cord fabric strip is short. When the width reaches a certain value t = B, it will affect the performance of the tire and cannot achieve the expected performance.

[0020] Due to the adoption of the above technical solution in this application, the C-shaped belt layer structure increases the circumferential tightening effect of the belt layer on the tire, restricts the circumferential deformation of the tire shoulder part during load driving, and also increases the overall strength of the tire, making the force on the tire crown area more uniform, reducing the heat generation in the tire crown area, greatly reducing the probability of delamination or cracking between the belt layer and the tread rubber, and at the same time improving the load-bearing capacity of the tire. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 Schematic cross-section of a heavy-duty low-profile radial tire with a "C-shaped structure", that is, a jointless braided multi-layer winding belt layer structure, shown in the embodiment of this application.

[0022] Figure 2 Partial enlarged view of the belt layer.

[0023] Figure 3 Schematic diagram of the braided multi-layer winding path.

[0024] Figure 4 Schematic diagram of the braided multi-layer winding belt layer structure. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0025] The following provides a detailed description of the specific embodiments of this application with reference to the accompanying drawings.

[0026] The cross-section of the embodiment is as Figure 1 shown, including a tread 1, a carcass 6, a sidewall 7, a bead 8, and a belt layer structure Figure 2 bonded to the carcass. The belt layer structure is composed of a No. 1 belt layer 5, a C-shaped belt layer 4, a No. 2 belt layer 3, and a No. 3 belt layer 2.

[0027] First, the No. 1 belt layer 5 is bonded to the carcass. The belt layer cord fabric is a steel cord coated with rubber and calendered cord fabric, and the angle between the belt layer and the tire crown circumferential direction is 10 - 60°.

[0028] The C-shaped belt layer is wound on the 1# belt layer, using a ply strip extruded from four steel cord plies. The designed width B of the C-shaped belt layer is 240 mm, the single-layer winding width T is 10 mm, and the number of single-layer winding turns N of the ply strip is N = B / T = 24. The number of spiral turns n required for the width B of the C-shaped belt layer to travel once is 4, and the number of turning points a on each side is a = N / n = 24 / 4 = 6, and the turning point angles on both sides are evenly staggered. The winding method is as Figure 3 shown. Starting from the positioning 0 of the center point O of the tread, a single ply strip is wound through 4*49 / 48*360° to the turning point A on one side for positioning: 120, and then it turns. When it winds through 2*4*49 / 48*360°, it reaches the turning point C on the other side for positioning: -120. The reciprocating multi-layer winding is carried out between the two shoulders in the same way, and after the winding is completed, it returns to the center point O. The width of the C-shaped belt layer is 10 - 20 mm wider than that of the 1# belt layer and 20 - 30 mm narrower than that of the 2# belt layer.

[0029] The 2# belt layer and the 3# belt layer are bonded to the C-shaped belt layer. The angle of the 2# belt layer is 10 - 60°, and the direction is opposite to that of the 1# belt layer. The angle of the 3# is 10 - 60°, the direction is the same as that of the 2# belt layer, and it is 30 - 70 mm narrower than the width of the 2# belt layer.

[0030] Durability data comparison

[0031] Taking a certain pattern all-steel radial tire of 60 series and 22.5 inches as an example, with a standard air pressure of 900 KPa and a standard load of 3750 kg, according to the ECE R54 and GB / T4501 standards, the durability test comparison is carried out between the same batch of tires with the zigzag winding and parallel spiral winding shared structure disclosed in Patent CN206733966U and the above experimental example tires.

[0032] The durability test conditions and test procedures are as follows:

[0033] Drum diameter: 1700 mm, rotational speed: 65 km / h,

[0034]

[0035] The comparison of machine tool data is as follows:

[0036] Group A Group B Control tire 82h21min 80h46min This design 93h53min 92h44min

[0037] It can be found through the comparison of the machine tool durability data that the braided winding belt structure can significantly improve the durability performance and load capacity of the tire.

[0038] The foregoing is a description of embodiments of the present application. Through the above description of the disclosed embodiments, those skilled in the art can implement or use the present application. Various modifications to these embodiments will be obvious to those skilled in the art. The general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but rather to the broadest scope consistent with the principles and novel features disclosed herein.

Claims

1. A heavy-duty radial tire with a jointless braided multi-layer wound belt structure, the tire comprising a tread, a belt layer, a carcass, a sidewall and a bead, the belt layer comprising a 1# belt layer, a 2# belt layer and a 3# belt layer, the 1# belt layer being attached to the carcass and being the innermost radially, the 3# belt layer being disposed on top of the 2# belt layer, characterized in that, The belt layer further includes a C-shaped belt layer. The C-shaped belt layer is disposed above the 1# belt layer, and the 2# belt layer is adhesively disposed above the C-shaped belt layer. The C-shaped belt layer is formed by winding a single cord strip starting from the middle of the tread and winding towards one end point of the belt layer. After reaching the end point, it turns and winds to the other end point, and thus performs reciprocating multi-layer winding at each turning point position of the winding layer. After the winding is completed, it returns to the starting position. The width of the C-shaped belt layer is 10 - 20 mm wider than the width of the 1# belt layer and 20 - 30 mm narrower than the width of the 2# belt layer. The 3# belt layer is 30 - 70 mm narrower than the width of the 2# belt layer. The number of layers of the C-shaped belt layer is 2W layers, where W is a non-zero natural number. Every 2 layers form a group, and the total number of layers is 2 or a multiple of 2. The starting point of the weaving and winding of the C-shaped belt layer is the center of the tread, and the end point returns to the starting position. The designed width of the C-shaped belt layer is B. A plurality of turning points are respectively arranged on the circumferences at both sides of B / 2 and -B / 2 on the belt forming drum. The designed width of the C-shaped belt layer is B, and the single-turn winding width is T, where T = the width t of the cord strip + the winding gap. The number of spiral turns n required for the cord strip to travel the width B of the C-shaped belt layer from one turning point to the next turning point (i.e., to walk once) is n ∈ {1, 2, 3, 4, 5, 6...}. Then the number of single-layer winding turns N of the cord strip = B / T, and the number of turning points a on one side = N / n. The turning points on both sides are evenly staggered.

2. The heavy-duty radial tire with a jointless braided multi-layer wound belt structure according to claim 1, wherein, The cord angle of the 1# belt layer forms an angle of 10 - 60° with the circumferential direction; the cord angle of the 2# belt layer forms an angle of 10 - 60° with the circumferential direction, and the direction is opposite to that of the 1# belt layer; the cord angle of the 3# belt layer forms an angle of 10 - 60° with the circumferential direction, and the direction is the same as that of the 2# belt layer.

3. A heavy-duty radial tire having a jointless braided multi-layer wound belt structure according to claim 1, characterized in that, The designed width B of the C-shaped belt layer = 240 mm, the single-turn winding width T = 10 mm, and the number of single-layer winding turns N of the cord strip = B / T = 24. The number of spiral turns n required for the cord strip to travel the width B of the C-shaped belt layer once is 4, and the number of turning points a on each side = N / n = 24 / 4 = 6. The turning points on both sides are evenly staggered in terms of angle. The winding method is to start from the center point O of the tread. The center point O is positioned at 0, wind through 2×49 / 48×360° to reach one turning point A on one side and then turn. The positioning of the turning point A is:

120. When winding through 4×49 / 48×360°, it reaches the turning point C on the other side. The positioning of the turning point C is: -120. Perform reciprocating multi-layer winding between the two shoulders in the same way, and return to the center point O after the winding is completed.

4. The heavy-duty radial tire with a jointless braided multi-layer wound belt structure according to claim 1, characterized in that, The cord strip of the C-shaped belt layer is formed by calendering or extruding several steel cord wires, and the width and thickness of the cord strip can be determined according to actual design requirements, and the surface is covered with rubber.

5. A heavy-duty radial tire having a jointless braided multi-layer wound belt structure according to claim 1, characterized in that, The number of cord wires in the cord strip of the C-shaped belt layer is 3 - 9, and the width is 5 - 20 mm.

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