Non-pneumatic tire with tire bead steel wire framework tread

Abstract

The invention provides a non-pneumatic tire containing a tire bead steel wire framework tread, and belongs to the technical field of non-pneumatic tires. A tread framework layer composed of at least two tire bead steel wire layers continuously arranged in the circumferential direction of the tire is embedded in the tread part of the non-pneumatic tire; the tire bead steel wire layers are arranged in the tire body, the shearing rubber layers are filled between the adjacent tire bead steel wire layers to form a shearing belt structure, and the bending rigidity characteristic of the tire bead steel wire is superior to that of a plurality of cord steel wires; the shearing belt structure has a shearing constraint effect on the middle shearing rubber layer through the two tire bead steel wire layers; according to the non-pneumatic tire, the deformation resistance of the tread part is enhanced, and the overall stiffness and rigidity are improved, so that the phenomenon of local collapse when the tread part bears radial loads is avoided, the bearing capacity of the non-pneumatic tire is guaranteed, and the technical problem that the bearing capacity is limited due to insufficient rigidity of the tread part of the non-pneumatic tire in the prior art is solved.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of non-pneumatic tires, and in particular relates to a non-pneumatic tire containing a bead wire framework tread. BACKGROUND

[0002] As a new type of tire structure, the non-pneumatic tire realizes load transmission through flexible spokes supporting the tread part and can be normally used without inflation, and has a wide application prospect in the fields of military equipment, engineering machinery and special vehicles. The tread part of the traditional non-pneumatic tire usually adopts a plurality of cord steel wires as a framework reinforcing material, and the plurality of cord steel wires are arranged along the tire circumference and embedded in the rubber layer to form a tread framework layer, so as to improve the anti-deformation ability of the tread part. However, the plurality of cord steel wires have low bending stiffness due to the weaving structure characteristics, and are prone to excessive bending deformation when bearing radial load, so that the tread part appears local collapse phenomenon at the joint area, thereby limiting the load-carrying capacity of the non-pneumatic tire. In the prior art, due to the insufficient bending stiffness of the plurality of cord steel wires and the lack of effective shear constraint mechanism of the tread framework layer, the overall stiffness of the tread part is poor, and when the non-pneumatic tire bears a large radial load, the tread deformation at the joint area is too large, which affects the stability and service life of the tire. That is to say, the prior art has the technical problem of limited load-carrying capacity caused by insufficient stiffness of the tread part of the non-pneumatic tire. SUMMARY

[0003] Therefore, the present application provides a non-pneumatic tire containing a bead wire framework tread, which can solve the technical problem of limited load-carrying capacity caused by insufficient stiffness of the tread part of the non-pneumatic tire in the prior art.

[0004] The present application is implemented as follows: the present application provides a non-pneumatic tire containing a bead wire framework tire tread, including a tread portion, a flexible spoke portion, and a rim portion, the tread portion is located at the outermost layer of the entire tire structure, the flexible spoke portion is located inside the tread portion, the rim portion is located inside the flexible spoke portion, the tread portion realizes load transmission and structural connection with the rim portion through the flexible spoke portion; the inner part of the tread portion is embedded with a tread framework layer, the tread framework layer contains at least two layers of bead wire layers arranged continuously along the tire circumference, the bead wire layers are filled with shear rubber layers to form a shear band structure, the shear band structure forms a shear constraint effect on the intermediate shear rubber layer through the two layers of bead wire layers, thereby improving the stiffness and overall stiffness of the tread portion, and at the same time, the bending stiffness characteristics of the bead wire itself are superior to those of the multi-strand cord wire, which enhances the anti-deformation ability of the tread portion and guarantees the load capacity of the non-pneumatic tire; the tread portion includes an outer tread rubber, a tread framework layer, and an inner transition rubber, the outer tread rubber is located at the outermost side of the tread portion and directly contacts the ground, and the inner transition rubber is located inside the tread framework layer and connected with the flexible spoke portion; the flexible spoke portion includes a plurality of flexible spoke units, which are uniformly distributed between the inner side of the tread portion and the outer side of the rim portion along the tire circumference; the rim portion includes a rim body, a rim inner ring, and a rim outer ring, the outer surface of the rim outer ring is fixedly connected with the inner end of the flexible spoke unit.

[0005] Among them, the tread framework layer includes a first bead wire layer, a second bead wire layer, and a first shear rubber layer located between the first bead wire layer and the second bead wire layer, the first bead wire layer is formed by a plurality of first bead wires arranged in parallel along the tire circumference, the second bead wire layer is formed by a plurality of second bead wires arranged in parallel along the tire circumference, the arrangement direction of the first bead wire and the second bead wire is consistent and extends along the tire circumference, and the first shear rubber layer is filled in the space between the first bead wire layer and the second bead wire layer and forms chemical adhesion with the surface plating layer of the first bead wire and the surface plating layer of the second bead wire through the vulcanization process.

[0006] Among them, the diameter of the first bead wire ranges from 1.0mm to 3.0mm, the base material of the first bead wire is high-carbon steel, the tensile strength of the first bead wire ranges from 1800MPa to 2800MPa, the bending stiffness of the first bead wire ranges from 180N·mm² to 350N·mm², the surface of the first bead wire is plated with a metal plating layer, the metal plating layer is selected from brass plating layer, red copper plating layer or bronze plating layer, and the thickness of the metal plating layer ranges from 0.08μm to 0.2μm; the material properties, diameter specifications, tensile strength, bending stiffness and surface plating layer properties of the second bead wire are consistent with those of the first bead wire.

[0007] The interval between the first bead wire layer and the second bead wire layer in the tire radial direction is defined as a first shear band thickness, the value of the first shear band thickness ranges from 3mm to 15mm, and the thickness of the first shear rubber layer is equal to the value of the first shear band thickness; the center interval between two adjacent first bead wires in the tire circumferential direction in the first bead wire layer is defined as a first circumferential interval, the value of the first circumferential interval ranges from 10mm to 20mm, and the center interval between two adjacent second bead wires in the tire circumferential direction in the second bead wire layer is defined as a second circumferential interval, the value of the second circumferential interval ranges from 10mm to 20mm.

[0008] The two ends of the first bead wire extend out of the width boundary of the tread portion in the tire axial direction, the extension length ranges from 8mm to 12mm, the extended end of the first bead wire is bent downward to form a hook-shaped fixing structure, the hook-shaped fixing structure is embedded in the sidewall rubber layer on the side of the tread portion, the bending angle of the hook-shaped fixing structure ranges from 90 degrees to 180 degrees, and the bending radius of the hook-shaped fixing structure ranges from 2mm to 8mm.

[0009] The tread skeleton layer further comprises a third bead wire layer, a fourth bead wire layer, a second shear rubber layer and a third shear rubber layer, the third bead wire layer is located on the inner side of the second bead wire layer, the second shear rubber layer is filled between the second bead wire layer and the third bead wire layer, the fourth bead wire layer is located on the inner side of the third bead wire layer, and the third shear rubber layer is filled between the third bead wire layer and the fourth bead wire layer; the thickness of the second shear rubber layer ranges from 3mm to 15mm, and the thickness of the third shear rubber layer ranges from 3mm to 15mm; the total number of bead wire layers in the tread skeleton layer ranges from 2 to 10 layers, and the proportion of the tread skeleton layer in the total thickness of the tread portion ranges from 50% to 90%.

[0010] The size ratio value between the first shear band thickness and the diameter of the first bead wire ranges from 2.0 to 8.0, when the size ratio value is less than 2.0, the thickness of the shear rubber layer is too thin, which leads to too large shear strain and easy tearing failure of the rubber layer, and when the size ratio value is greater than 8.0, the thickness of the shear rubber layer is too thick, which leads to weakening of the shear constraint effect and inability to effectively improve the tread stiffness; the size ratio value between the first circumferential interval and the diameter of the first bead wire ranges from 5.0 to 12.0, when the size ratio value is less than 5.0, the interval between adjacent bead wires is too small, which leads to too high bead wire density and increases the weight of the tread, and when the size ratio value is greater than 12.0, the interval between adjacent bead wires is too large, which leads to insufficient local stiffness of the tread and easy local depression under load.

[0011] wherein, there is a thickness proportion relationship between the total thickness of the tread skeleton layer and the total thickness of the tread portion, the total thickness of the tread skeleton layer is equal to the thickness proportion coefficient multiplied by the total thickness of the tread portion, the numerical range of the thickness proportion coefficient is 0.50 to 0.90, when the thickness proportion coefficient is 0.50, it means that the tread skeleton layer accounts for 50% of the tread thickness, so that there is a relatively thick outer tread rubber for providing good grip performance, when the thickness proportion coefficient is 0.90, it means that the tread skeleton layer accounts for 90% of the tread thickness, so that the tread stiffness is maximized but the outer tread rubber is too thin to shorten the wear life.

[0012] wherein, there is a stiffness matching relationship between the radial stiffness of the flexible spoke unit and the bending stiffness of the tread skeleton layer, the radial stiffness of the flexible spoke unit is equal to the stiffness matching coefficient multiplied by the bending stiffness of the tread skeleton layer and the number of flexible spoke units divided by 100, the numerical range of the stiffness matching coefficient is 0.3 to 1.2, when the stiffness matching coefficient is small, the radial stiffness of the flexible spoke unit is relatively low, so as to provide better cushioning performance but the carrying capacity is limited, when the stiffness matching coefficient is large, the radial stiffness of the flexible spoke unit is relatively high, so as to improve the carrying capacity but the cushioning performance decreases.

[0013] wherein, there is an angle deformation relationship between the initial inclination angle of the flexible spoke unit and the radial deformation amount of the non-pneumatic tire, the radial deformation amount of the non-pneumatic tire is equal to the difference between the radial length of the flexible spoke unit and the cosine value of the initial inclination angle, plus the deformation correction coefficient multiplied by the design load divided by the radial stiffness of the flexible spoke unit, the numerical range of the deformation correction coefficient is 0.8 to 1.2, when the initial inclination angle is large, the geometric deformation contribution increases, resulting in an increase in the radial deformation amount, when the radial stiffness of the flexible spoke unit is small, the elastic deformation under the same load increases, resulting in an increase in the radial deformation amount.

[0014] Optionally, there is a thickness embedding depth relationship between the thickness of the outer tread rubber and the embedding depth of the outermost bead wire layer of the tread skeleton layer, the thickness embedding depth proportion value ranges from 1.5 to 4.0, when the thickness embedding depth proportion value is less than 1.5, the outer tread rubber is too thin, resulting in the bead wire layer being too close to the tread surface and being easily exposed after wear, when the thickness embedding depth proportion value is greater than 4.0, the outer tread rubber is too thick, resulting in the bead wire layer being embedded too deeply and failing to fully play a supporting role.

[0015] Optionally, the outer surface of the rim flange is uniformly provided with a plurality of connecting grooves in the tire circumferential direction, the number of the connecting grooves is consistent with the number of the flexible spoke units, the slot of each connecting groove faces the outside of the tire, the inner end of each flexible spoke unit is accommodated in the connecting groove, and the inner end of the flexible spoke unit is inserted into the connecting groove and fixedly connected by vulcanization adhesive or mechanical locking structure; the groove depth of the connecting groove ranges from 3mm to 15mm, and the groove width of the connecting groove ranges from 4mm to 25mm.

[0016] Optionally, there is a groove depth height relationship between the groove depth of the connecting groove and the cross-sectional height of the flexible spoke unit, and the groove depth height ratio ranges from 0.6 to 1.2. When the groove depth height ratio is less than 0.6, the insufficient depth of the connecting groove results in insufficient insertion depth of the inner end of the flexible spoke unit, and the connection strength is reduced. When the groove depth height ratio is greater than 1.2, the excessive depth of the connecting groove results in excessive insertion of the inner end of the flexible spoke unit, and stress concentration damage may occur.

[0017] Optionally, the flexible spoke unit is made of thermoplastic polyurethane elastomer material or thermoplastic polyester elastomer material or natural rubber material, the Shore hardness of the flexible spoke unit ranges from 75A to 95A, the cross-sectional shape of the flexible spoke unit is selected from rectangular cross-section, trapezoidal cross-section, I-shaped cross-section or honeycomb cross-section, the cross-sectional width of the flexible spoke unit ranges from 3mm to 20mm, the cross-sectional height of the flexible spoke unit ranges from 2mm to 15mm, and the radial length of the flexible spoke unit ranges from 30mm to 200mm; the number of the flexible spoke unit ranges from 20 to 120, and the flexible spoke unit presents an initial inclined shape in the non-load state, and the initial inclination angle between the flexible spoke unit and the radial direction of the tire ranges from 5 degrees to 25 degrees.

[0018] Optionally, the first shear rubber layer, the second shear rubber layer and the third shear rubber layer are made of a blend of natural rubber and butadiene rubber, the Shore hardness of the shear rubber layer ranges from 55HA to 85HA, the tensile strength of the shear rubber layer ranges from 15MPa to 30MPa, and the elongation at break of the shear rubber layer ranges from 300% to 600%; the shear rubber layer undergoes a chemical adhesion reaction with the metal plating layer on the surface of the bead wire during vulcanization, and the adhesion strength between the shear rubber layer and the bead wire ranges from 15MPa to 40MPa.

[0019] Optionally, the shear modulus of the shear rubber layer ranges from 0.5 MPa to 3.0 MPa, and the shear strain value of the shear rubber layer in a maximum shear strain state ranges from 20% to 80%; the shear deformation of the shear rubber layer absorbs part of the deformation energy and converts the deformation energy into heat energy dissipation through viscoelastic damping effect, thereby reducing the vibration amplitude of the non-pneumatic tire during rolling and improving the riding comfort; the bending stiffness value of the bead wire is significantly higher than that of the multi-strand cord wire with the same diameter, and the radial deformation amount of the tread portion using the bead wire skeleton is 30% to 50% lower than that of the tread portion using the cord wire skeleton under the same radial load condition.

[0020] The present application enhances the deformation resistance of the tread portion by embedding a tread skeleton layer composed of at least two layers of bead wires inside the tread portion and filling a shear rubber layer between adjacent bead wire layers to form a shear band structure. The bead wire, as a single solid wire, has a bending stiffness significantly higher than that of a multi-strand cord wire with the same diameter, which can effectively resist bending deformation caused by radial load. At the same time, the shear band structure forms a shear constraint effect on the intermediate shear rubber layer through the two layers of bead wires, and when the tread portion is subjected to radial load, the shear rubber layer between adjacent bead wire layers is subjected to shear strain, which limits the excessive bending deformation of the bead wire layer through the shear constraint mechanism, thereby maintaining the overall stiffness of the tread portion and avoiding local collapse, and improving the load capacity of the non-pneumatic tire. In summary, the present application solves the technical problem of limited load capacity caused by insufficient stiffness of the tread portion of the non-pneumatic tire mentioned in the background art. BRIEF DESCRIPTION OF DRAWINGS

[0021] Fig. 1 It is a schematic diagram of the overall structure of the non-pneumatic tire.

[0022] Fig. 2 It is a schematic diagram of the cross-sectional structure of the tread portion.

[0023] Fig. 3 It is a schematic diagram of the shear band structure of the tread skeleton layer.

[0024] Fig. 4 It is a schematic diagram of the connection structure of the rim portion and the flexible spoke.

[0025] The reference signs in the drawings are explained in detail as follows: 01, tread portion, 02, flexible spoke portion, 03, rim portion, 11, outer tread rubber, 12, tread skeleton layer, 13, inner transition rubber, 121, first bead wire layer, 122, second bead wire layer, 123, third bead wire layer, 124, fourth bead wire layer, 21, flexible spoke unit, 31, rim body, 32, rim inner ring, 33, rim outer ring. DETAILED DESCRIPTION

[0026] In order to make the purposes, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application are clearly and completely described below.

[0027] As shown in Figs. 1 to 4 Fig. 1 is a schematic diagram of the overall structure of a non-pneumatic tire provided by the present application, which includes a tread portion 01, a flexible spoke portion 02 and a rim portion 03. The tread portion is located at the outermost layer of the overall tire structure, the flexible spoke portion is located at the inner side of the tread portion, and the rim portion is located at the inner side of the flexible spoke portion. The tread portion is connected to the rim portion through the flexible spoke portion to realize load transmission and structural connection. A tread skeleton layer is embedded in the interior of the tread portion, which includes at least two layers of bead wire layers arranged continuously along the tire circumferential direction. The bead wire layers are filled with shear rubber layers to form a shear band structure. The shear band structure forms shear constraint on the intermediate shear rubber layer through the two layers of bead wire layers, thereby improving the stiffness and overall stiffness of the tread portion. Meanwhile, the anti-deformation ability of the tread portion is enhanced and the load-bearing capacity of the non-pneumatic tire is ensured by utilizing the bending stiffness characteristics of the bead wire which are superior to those of the multi-strand cord wire.

[0028] The tread portion includes an outer tread rubber 11, the tread skeleton layer 12 and an inner transition rubber 13. The outer tread rubber is located at the outermost side of the tread portion and directly contacts the ground. The inner side surface of the outer tread rubber is fixedly connected to the outer side surface of the tread skeleton layer in a vulcanization adhesion manner. The inner transition rubber is located at the inner side of the tread skeleton layer and is fixedly connected to the inner side surface of the tread skeleton layer in a vulcanization adhesion manner. The inner side surface of the inner transition rubber is fixedly connected to the outer side end portion of the flexible spoke portion in a vulcanization adhesion manner or a mechanical locking manner. The outer tread rubber is made of a blend of natural rubber and styrene-butadiene rubber. The Shore hardness of the outer tread rubber ranges from 60HA to 95HA. The thickness of the outer tread rubber ranges from 3mm to 40mm. The outer surface of the outer tread rubber is uniformly distributed with a plurality of pattern grooves along the tire circumferential direction. The depth of the pattern grooves ranges from 2mm to 15mm. The width of the pattern grooves ranges from 3mm to 20mm. The spacing of the pattern grooves along the tire circumferential direction ranges from 8mm to 50mm.

[0029] The first bead wire layer is formed by a plurality of first bead wires arranged in parallel along the tire circumferential direction, the second bead wire layer is formed by a plurality of second bead wires arranged in parallel along the tire circumferential direction, the arrangement directions of the first bead wires and the second bead wires are consistent and both extend along the tire circumferential direction, and the first shear rubber layer is filled in the space between the first bead wire layer and the second bead wire layer and forms chemical bonding with the surface plated layers of the first bead wires and the second bead wires through a vulcanization process. The diameter of the first bead wire ranges from 1.0 mm to 3.0 mm, the base material of the first bead wire is high-carbon steel, the tensile strength of the first bead wire ranges from 1800 MPa to 2800 MPa, the bending stiffness of the first bead wire ranges from 180 N / mm2 to 350 N / mm2, the surface of the first bead wire is plated with a metal plating layer, the metal plating layer is selected from a brass plating layer, a red copper plating layer or a bronze plating layer, and the thickness of the metal plating layer ranges from 0.08 μm to 0.2 μm. The material properties, diameter specifications, tensile strength, bending stiffness and surface plating layer properties of the second bead wire are consistent with those of the first bead wire.

[0030] The distance between the first bead wire layer and the second bead wire layer in the tire radial direction is defined as the first shear band thickness, the numerical value of the first shear band thickness ranges from 3 mm to 15 mm, the thickness value of the first shear rubber layer is equal to the first shear band thickness, the center distance between two adjacent first bead wires in the first bead wire layer along the tire circumferential direction is defined as the first circumferential distance, the numerical value of the first circumferential distance ranges from 10 mm to 20 mm, the center distance between two adjacent second bead wires in the second bead wire layer along the tire circumferential direction is defined as the second circumferential distance, and the numerical value of the second circumferential distance ranges from 10 mm to 20 mm. The two ends of the first bead wire extend out of the width boundary of the tread portion along the tire axial direction, the extension length ranges from 8 mm to 12 mm, the extended end of the first bead wire is bent downward to form a hook-shaped fixing structure, the hook-shaped fixing structure is embedded in the sidewall rubber layer inside the side portion of the tread portion, the bending angle of the hook-shaped fixing structure ranges from 90 degrees to 180 degrees, and the bending radius of the hook-shaped fixing structure ranges from 2 mm to 8 mm.

[0031] The tire tread skeleton layer also includes a third bead wire layer 123, a fourth bead wire layer 124, a second shear rubber layer, and a third shear rubber layer. The third bead wire layer is located inside the second bead wire layer, the second shear rubber layer is filled between the second bead wire layer and the third bead wire layer, the fourth bead wire layer is located inside the third bead wire layer, and the third shear rubber layer is filled between the third bead wire layer and the fourth bead wire layer. The third bead wire layer is formed by a plurality of third bead wires arranged in parallel along the tire circumferential direction, and the fourth bead wire layer is formed by a plurality of fourth bead wires arranged in parallel along the tire circumferential direction. The material specifications, diameter sizes, mechanical properties, and surface coating characteristics of the third bead wires and the fourth bead wires are consistent with those of the first bead wires. The thickness of the second shear rubber layer ranges from 3 mm to 15 mm, the thickness of the third shear rubber layer ranges from 3 mm to 15 mm, the net spacing between the second bead wire layer and the third bead wire layer in the tire radial direction ranges from 2 mm to 10 mm, and the net spacing between the third bead wire layer and the fourth bead wire layer in the tire radial direction ranges from 2 mm to 10 mm.

[0032] The total number of bead wire layers in the tire tread skeleton layer ranges from 2 to 10. When the total number of bead wire layers is 2, one group of shear band structures is formed. When the total number of bead wire layers is 3, two groups of shear band structures are formed. When the total number of bead wire layers is 4, three groups of shear band structures are formed. And so on, until when the total number of bead wire layers is 10, nine groups of shear band structures are formed. The position of the tire tread skeleton layer along the tire tread thickness direction ranges from one-third to two-thirds of the total thickness of the tire tread. The total thickness of the tire tread portion ranges from 8 mm to 100 mm, and the proportion of the tire tread skeleton layer to the total thickness of the tire tread portion ranges from 50% to 90%.

[0033] The flexible spoke portion comprises a plurality of flexible spoke units 21, which are uniformly distributed between the inner side of the tread portion and the outer side of the rim portion along the tire circumferential direction, the outer end of each flexible spoke unit is fixedly connected with the inner side of the tread portion by vulcanization adhesion or mechanical connection, and the inner end of each flexible spoke unit is fixedly connected with the outer side of the rim portion by vulcanization adhesion or bolt connection or buckle connection. The flexible spoke unit is made of thermoplastic polyurethane elastomer material or thermoplastic polyester elastomer material or natural rubber material, the Shore hardness of the flexible spoke unit ranges from 75A to 95A, the cross-sectional shape of the flexible spoke unit is selected from rectangular cross-section, trapezoidal cross-section, I-shaped cross-section and honeycomb cross-section, the cross-sectional width of the flexible spoke unit ranges from 3mm to 20mm, the cross-sectional height of the flexible spoke unit ranges from 2mm to 15mm, and the radial length of the flexible spoke unit ranges from 30mm to 200mm.

[0034] The number of flexible spoke units ranges from 20 to 120, the distribution interval of the flexible spoke units along the tire circumferential direction is determined according to the number of flexible spoke units and the circumference size of the tire, and the circumferential included angle between two adjacent flexible spoke units ranges from 3 degrees to 18 degrees. The flexible spoke unit presents an initial outwardly inclined state in the non-load bearing state, the initial inclination angle between the flexible spoke unit and the tire radial direction ranges from 5 degrees to 25 degrees, the flexible spoke unit is bent and deformed when the non-pneumatic tire bears radial load, the flexible spoke unit located in the contact area bears compression load and bends inwardly, and the flexible spoke unit located in the non-contact area bears tensile load and remains in the outwardly inclined state or slightly bends outwardly.

[0035] The rim portion comprises a rim body 31, a rim inner ring 32 and a rim outer ring 33, the rim body is in the form of a circular ring structure, the geometric center axis of the rim body coincides with the rotation axis of the tire, the rim inner ring is located at the inner side of the rim body and is fixedly connected with the wheel bearing seat by bolt connection, the rim outer ring is located at the outer side of the rim body, and the outer surface of the rim outer ring is fixedly connected with the inner end of the flexible spoke unit by vulcanization adhesion or mechanical connection. The rim body is made of aluminum alloy material or steel material or magnesium alloy material, the radial thickness of the rim body ranges from 5mm to 30mm, the axial width of the rim body ranges from 50mm to 300mm, and the outer diameter of the rim outer ring ranges from 200mm to 800mm. The outer surface of the rim outer ring is uniformly distributed with a plurality of connecting grooves along the tire circumference, the number of the connecting grooves is consistent with the number of the flexible spoke units, the slot opening of each connecting groove faces the outer side of the tire, and the inner end of each flexible spoke unit is accommodated in each connecting groove, and the inner end of the flexible spoke unit is inserted into the connecting groove and fixedly connected by vulcanization adhesive or mechanical locking structure. The groove depth of the connecting groove ranges from 3mm to 15mm, the groove width of the connecting groove ranges from 4mm to 25mm, and the bottom shape of the connecting groove is selected from plane, arc surface or wedge shape.

[0036] The first shear rubber layer, the second shear rubber layer and the third shear rubber layer are all made of a blend of natural rubber and butadiene rubber, the Shore hardness of the shear rubber layer ranges from 55HA to 85HA, the tensile strength of the shear rubber layer ranges from 15MPa to 30MPa, and the elongation at break of the shear rubber layer ranges from 300% to 600%. The shear rubber layer and the metal plating layer on the surface of the bead wire have a chemical adhesion reaction during vulcanization, and the chemical adhesion reaction depends on the action of vulcanization accelerators and vulcanization crosslinking agents. The adhesion strength between the shear rubber layer and the bead wire ranges from 15MPa to 40MPa.

[0037] The two sidewall positions of the tread portion are respectively provided with a sidewall reinforcing layer, the sidewall reinforcing layer is made of polyester cord or nylon cord, and the sidewall reinforcing layer is fixedly connected with the sidewall rubber layer of the tread portion by vulcanization adhesion, the thickness of the sidewall reinforcing layer ranges from 1mm to 5mm, and the width of the sidewall reinforcing layer along the tire axial direction ranges from 10mm to 50mm. The sidewall rubber layer is made of a blend of natural rubber and butyl rubber, the Shore hardness of the sidewall rubber layer ranges from 50HA to 75HA, and the thickness of the sidewall rubber layer ranges from 2mm to 20mm.

[0038] A transition connecting layer is arranged between the inner side of the tread portion and the outer end of the flexible spoke portion, the transition connecting layer is made of rubber material with hardness gradient change, the Shore hardness of the side close to the tread portion ranges from 65HA to 90HA, the Shore hardness of the side close to the flexible spoke portion ranges from 70A to 90A, and the thickness of the transition connecting layer ranges from 3mm to 20mm. A plurality of transition reinforcing cords are uniformly embedded inside the transition connecting layer along the tire circumferential direction, the transition reinforcing cords are made of polyester fiber or nylon fiber or aramid fiber, the diameter of the transition reinforcing cords ranges from 0.5mm to 2.5mm, and the circumferential spacing between adjacent two transition reinforcing cords ranges from 3mm to 15mm.

[0039] The first bead wire in the first bead wire layer forms a closed ring structure in the tire circumferential direction, the circumferential length of the first bead wire is equal to the circumference size of the tire, and the two ends of the first bead wire are connected by butt welding, pressure sleeve or twisting. The butt welding adopts resistance welding process or laser welding process, and the strength of the butt welding position is not less than 85% of the strength of the first bead wire body. The bead wires in the second bead wire layer, the third bead wire layer and the fourth bead wire layer all adopt the same circumferential connection mode to form a closed ring structure.

[0040] The width of the tread skeleton layer in the tire width direction ranges from 60% to 95% of the total width of the tread portion, and the distance between the two side edges of the tread skeleton layer and the side wall edges of the tread portion ranges from 5mm to 50mm. The width of the outer tread rubber in the tire width direction is equal to the total width of the tread portion, and the outer tread rubber completely covers the outer surface of the tread skeleton layer and extends to the two side wall positions of the tread portion.

[0041] The inner ring part of the rim body is provided with a plurality of mounting holes, which are uniformly distributed along the tire circumferential direction, and the number of mounting holes ranges from 4 to 12. Each mounting hole penetrates the thickness direction of the rim body, and each mounting hole accommodates a bolt rod inside. The bolt rod penetrates the mounting hole and is screw connected with the threaded hole on the wheel bearing seat. The hole diameter of the mounting hole ranges from 8mm to 25mm, and the circumferential included angle between adjacent two mounting holes ranges from 30 degrees to 90 degrees.

[0042] The stiffness characteristic of the flexible spoke unit in the tire radial direction is jointly determined by the material characteristic, cross-sectional shape, and radial length of the flexible spoke unit, the radial stiffness of the flexible spoke unit ranges from 50 N / mm to 500 N / mm, and the radial deformation amount of the tread portion in the ground contact region when the non-pneumatic tire bears a 300 kg radial load ranges from 0.8 mm to 2.5 mm. The stiffness of the flexible spoke unit in the tire circumferential direction is significantly higher than the stiffness of the flexible spoke unit in the tire radial direction, and the ratio of the circumferential stiffness of the flexible spoke unit to the radial stiffness ranges from 1.5 to 5.0.

[0043] The multi-layer bead wire layer in the tread skeleton layer realizes synergistic load bearing through the shear deformation mechanism of the shear rubber layer, the bead wire layer located in the ground contact region bends inwardly and deforms when the tread portion bears a radial load, the shear rubber layer between the adjacent two layers of bead wire layers bears shear strain, the shear modulus of the shear rubber layer ranges from 0.5 MPa to 3.0 MPa, and the shear strain value of the shear rubber layer in the maximum shear strain state ranges from 20% to 80%. The shear deformation of the shear rubber layer absorbs part of the deformation energy and converts the deformation energy into heat energy dissipation through viscoelastic damping effect, thereby reducing the vibration amplitude of the non-pneumatic tire during rolling and improving the ride comfort.

[0044] The bending stiffness value of the bead wire is significantly higher than the bending stiffness value of the multi-strand cord wire with the same diameter, the bending stiffness of the bead wire is about 250 N2mm and the bending stiffness of the multi-strand cord wire is about 170 N2mm when the diameters are both 1.6 mm, and the bending stiffness advantage ratio of the bead wire is about 47%. The high bending stiffness characteristic of the bead wire directly improves the ability of the tread portion to resist radial deformation, and the radial deformation amount of the tread portion with a bead wire skeleton is reduced by 30% to 50% compared with the radial deformation amount of the tread portion with a cord wire skeleton under the same radial load condition.

[0045] The non-pneumatic tire is first arranged with the first bead wire at a predetermined circumferential interval on the surface of a forming drum to form the first bead wire layer during the manufacturing process, then a first layer of unvulcanized rubber is coated on the surface of the first bead wire layer to form the first shear rubber layer, then the second bead wire is arranged on the surface of the first shear rubber layer at a predetermined circumferential interval to form the second bead wire layer, and the alternating stacking of multiple bead wire layers and multiple shear rubber layers is sequentially completed to form the blank body of the tread skeleton layer, the unvulcanized rubber compound of the outer layer tread rubber is attached to the outer surface of the blank body of the tread skeleton layer, and the unvulcanized rubber compound of the inner layer transition rubber is attached to the inner surface of the blank body of the tread skeleton layer. The blank body of the entire tread portion is subjected to a heating and pressurizing process inside a vulcanization mold to achieve vulcanization forming, the vulcanization temperature ranges from 150°C to 180°C, the vulcanization time ranges from 20 minutes to 60 minutes, and the vulcanization pressure ranges from 1.0 MPa to 2.5 MPa.

[0046] The flexible spoke portion is manufactured by an injection molding process or a casting molding process or a compression molding process, the outer end of the flexible spoke unit is reserved with a connecting boss structure during the molding process, the shape of the connecting boss structure is selected as a cylindrical or rectangular columnar or T-shaped boss, the connecting boss structure is inserted into the reserved connecting groove inside the inner side of the tread portion and is fixedly connected through a vulcanization adhesive. The inner end of the flexible spoke unit is reserved with a connecting embedding part during the molding process, the connecting embedding part is inserted into the connecting groove inside the rim outer ring and is fixedly connected through a vulcanization adhesive or a mechanical locking structure.

[0047] The rim portion is manufactured by a casting process or a forging process or a machining process, the connecting groove of the rim outer ring is formed by mechanical milling processing or electric spark processing or laser cutting processing, the groove wall surface of the connecting groove is subjected to sand blasting treatment or chemical roughening treatment to enhance the adhesion strength with the inner end of the flexible spoke unit. The mounting hole of the rim body is formed by drilling or punching, and the inner wall surface of the mounting hole is subjected to thread processing or smooth surface.

[0048] The deformation mode of the overall structure of the non-pneumatic tire under radial load is that the tread portion locally compresses radially at the contact area, the flexible spoke unit below the contact area bears the compression load and bends inwardly, the multiple bead wire layers in the tread skeleton layer bend cooperatively at the contact area, and the shear rubber layer between adjacent bead wire layers bears shear strain and limits the excessive bending deformation of the bead wire layer through the shear constraint mechanism, thereby maintaining the overall stiffness of the tread portion and avoiding local collapse. The contact area of the non-pneumatic tire continuously migrates along the tire circumference during rolling, the flexible spoke unit bears compression load and bends inwardly when entering the contact area, and releases the compression load and restores the initial inclined state after leaving the contact area, the periodic bending deformation and recovery process of the flexible spoke unit is accompanied by energy dissipation effect, and the energy dissipation effect mainly comes from the viscoelastic damping of the flexible spoke unit material and the shear damping of the shear rubber layer.

[0049] Further, the first shear band thickness and the diameter of the first bead wire have a size ratio relationship, and the size ratio relationship satisfies the following inequality constraint condition:

[0050] ;

[0051] When the size ratio is less than 2.0, the thickness of the shear rubber layer is too thin to cause excessive shear strain, which is easy to cause rubber layer tearing failure, and when the size ratio is greater than 8.0, the thickness of the shear rubber layer is too thick to weaken the shear constraint effect and cannot effectively improve the tread stiffness, so the size ratio is limited to the range of 2.0 to 8.0 to ensure the reliability and effectiveness of the shear band structure.

[0052] Further, the first circumferential spacing and the diameter of the first bead wire have a size ratio relationship, and the size ratio relationship satisfies the following inequality constraint condition:

[0053] ;

[0054] When the size ratio is less than 5.0, the spacing between adjacent bead wires is too small to cause the bead wire density to be too high, which increases the tread weight and has limited improvement, and when the size ratio The spacing between adjacent bead wires is too large when greater than 12.0, which results in insufficient local stiffness of the tread and easy local indentation under load, so the dimension ratio is limited in the range of 5.0 to 12.0 to balance the tread weight and stiffness performance.

[0055] Further, the total thickness of the tread skeleton layer is in a thickness ratio relationship with the total thickness of the tread portion , which is expressed by the following equation:

[0056] ;

[0057] wherein, is a thickness ratio coefficient and the numerical range of is 0.50 to 0.90, the equation is used to determine the proportion of the tread skeleton layer in the thickness direction of the tread, the input includes the total thickness of the tread portion and the thickness ratio coefficient , and the output is the total thickness of the tread skeleton layer , when is 0.50, it means that the tread skeleton layer accounts for 50% of the tread thickness, so that there is a relatively thick outer tread rubber to provide good grip performance, when is 0.90, it means that the tread skeleton layer accounts for 90% of the tread thickness, so that the tread stiffness is maximized, but the outer tread rubber is thin, resulting in a shortened wear life.

[0058] Further, the radial stiffness of the flexible spoke unit is in a stiffness matching relationship with the bending stiffness of the tread skeleton layer , which is expressed by the following equation:

[0059] ;

[0060] wherein, is a stiffness matching coefficient and the numerical range of is 0.3 to 1.2, is the number of the flexible spoke unit, the equation is used to ensure that the radial stiffness of the flexible spoke portion is coordinated with the bending stiffness of the tread skeleton layer, so as to avoid stress concentration caused by structural stiffness mismatch, the input includes the bending stiffness of the tread skeleton layer , the number of the flexible spoke unit and the stiffness matching coefficient , and the output is the radial stiffness of the flexible spoke unit , when The radial stiffness of the flexible spoke unit is relatively low when the value is small, thereby providing better cushioning performance but limited load-carrying capacity, and the radial stiffness of the flexible spoke unit is relatively high when the value is large, thereby improving the load-carrying capacity but reducing the cushioning performance.

[0061] Further, the initial inclination angle of the flexible spoke unit and the radial deformation amount of the non-pneumatic tire have an angle deformation relationship, and the angle deformation relationship is expressed by the following equation:

[0062] ;

[0063] wherein, is the radial length of the flexible spoke unit, is a deformation correction coefficient, and the value of the deformation correction coefficient is in the range of 0.8 to 1.2, the equation is used to predict the radial deformation amount of the non-pneumatic tire under the load state, the inputs include the radial length of the flexible spoke unit , the initial inclination angle of the flexible spoke unit , the design load , the radial stiffness of the flexible spoke unit , and the deformation correction coefficient , and the output is the radial deformation amount of the non-pneumatic tire , when the initial inclination angle is large, the geometric deformation contribution increases, resulting in an increase in the radial deformation amount, and when the radial stiffness of the flexible spoke unit is small, the elastic deformation under the same load increases, resulting in an increase in the radial deformation amount.

[0064] Further, the thickness of the outer tread rubber and the embedding depth of the outermost bead wire layer of the tread skeleton layer have a thickness embedding relationship, and the thickness embedding relationship satisfies the following inequality constraint condition:

[0065] ;

[0066] wherein, when the thickness ratio is less than 1.5, the outer tread rubber is too thin, causing the bead wire layer to be too close to the tread surface and easily exposed after wear, and when the thickness ratio is greater than 4.0, the outer tread rubber is too thick, causing the bead wire layer to be embedded too deeply and unable to fully play a supporting role, therefore, the thickness ratio is limited to the range of 1.5 to 4.0 for balancing the wear life and supporting performance.

[0067] Further, the groove depth of the connecting groove ​a groove depth height relationship between the cross-sectional height of the flexible spoke unit and the cross-sectional height of the connecting groove, the groove depth height relationship satisfying the following inequality constraint:

[0068] ;

[0069] wherein, when the groove depth ratio is less than 0.6, the connecting groove depth is insufficient to cause the inner end of the flexible spoke unit to be inserted deep enough to reduce the connecting strength, and when the groove depth ratio is greater than 1.2, the connecting groove depth is too large to cause the inner end of the flexible spoke unit to be inserted too deep to possibly cause stress concentration damage, therefore the groove depth ratio is limited to the range of 0.6 to 1.2 to ensure the connecting reliability and structural durability.

[0070] Optionally, when the total number of the bead wire layers increases, the total thickness of the tread skeleton layer needs to be increased accordingly, and the amount of increase is equal to the sum of the newly added number of layers and the thickness of a single layer, i.e. Meanwhile, the thickness of the outer layer of the tread rubber or the thickness of the inner layer of the transition rubber needs to be reduced accordingly to keep the total thickness of the tread portion substantially unchanged or only slightly adjusted, this constraint is used to control the total thickness of the tread while increasing the number of bead wire layers to improve the load capacity, so as to avoid excessive weight increase.

[0071] Optionally, when the width of the tread portion increases, the circumferential length of the bead wire needs to remain unchanged but the arrangement number or arrangement density of the bead wire in the tire width direction needs to be increased accordingly, and the amount of increase of the arrangement density satisfies the relationship: wherein is the areal density of the bead wire, with the unit of root per square mm, is the tread width, is a density adjustment coefficient, and the numerical range of is 0.3 to 0.8, this constraint is used to ensure that the wide tread has sufficient stiffness support.

[0072] ​It should be noted that the present application also solves the technical problem that the non-pneumatic tire in the prior art has a large vibration amplitude during rolling, resulting in poor driving comfort. The present application achieves energy dissipation through the viscoelastic damping effect of the shear rubber layer. When the tread portion deforms in the contact area, the shear rubber layer between the adjacent bead wire layers bears shear strain. During the shear deformation process, the shear rubber layer converts part of the deformation energy into heat energy dissipation, reducing the vibration amplitude during tire rolling. At the same time, the flexible spoke unit undergoes periodic bending deformation and recovery when entering and leaving the contact area. The viscoelastic damping of the flexible spoke unit material further absorbs vibration energy. The double damping mechanism cooperates to effectively reduce the vibration transmission of the non-pneumatic tire, improving the driving comfort of the vehicle. In addition, the present application also solves the technical problem that the stiffness matching between the tread skeleton layer and the flexible spoke portion is improper, resulting in stress concentration. By establishing the stiffness matching relationship between the radial stiffness of the flexible spoke unit and the bending stiffness of the tread skeleton layer, the deformation coordination of the two during loading is ensured, avoiding the local stress concentration phenomenon caused by stiffness mismatch, prolonging the service life of the non-pneumatic tire.

[0073] Specifically, the principle of the present application is that the present application uses bead wire instead of traditional multi-strand cord steel wire as the reinforcing material of the tread skeleton layer. The bead wire is a single solid steel wire structure, and its cross section is a complete circle without gaps between the strands inside, so the entire cross section can uniformly participate in bending resistance when bearing bending load, making the bending stiffness increase by about 47% compared to multi-strand cord steel wire. When the non-pneumatic tire bears radial load, the bead wire layer in the contact area will deform inwardly. Due to the high bending stiffness of the bead wire, it can effectively resist bending deformation and reduce the radial compression of the tread portion. At the same time, the shear rubber layer filled between the multiple bead wire layers forms a shear band structure. When the adjacent bead wire layers displace relative to each other, the shear rubber layer bears shear strain. The shear rubber layer generates shear restraint force through its shear modulus, limiting the relative sliding between the adjacent bead wire layers, so that the multiple bead wire layers bear cooperatively rather than individually deform. This cooperative bearing mechanism further improves the overall stiffness of the tread portion, ensuring that the non-pneumatic tire can maintain sufficient bearing capacity without local collapse when bearing large radial load.

[0074] A specific embodiment 1 of the present application is provided below, which provides a non-pneumatic tire applied to a light passenger vehicle, the total thickness of the tire tread portion is 25 mm, the width of the tire tread portion is 180 mm, and the outer diameter size of the rim is 400 mm. The tire tread portion includes three main components, i.e., an outer tread rubber, a tread skeleton layer, and an inner transition rubber. The outer tread rubber is made of natural rubber and styrene-butadiene rubber blended at a mass ratio of 70:30, the Shore hardness is 70HA, and the thickness is 8 mm. The outer surface is uniformly distributed with longitudinal pattern grooves along the tire circumferential direction. The depth of the pattern grooves is 6 mm, the width is 8 mm, and the circumferential distance between adjacent pattern grooves is 25 mm. The pattern grooves are designed to provide good drainage performance and enhance the grip between the tire and the ground. The tread skeleton layer is located inside the outer tread rubber. The skeleton layer includes two layers of bead wire layers and a shear rubber layer filled between the two layers of bead wire layers. The first bead wire layer is formed by 46 first bead wires arranged in parallel along the tire circumferential direction. The diameter of each first bead wire is 1.6 mm, the material is high-carbon steel, the tensile strength is 2200 MPa, the bending stiffness is 240 N· The surface is coated with a 0.12-micron-thick brass plating. The circumferential spacing between two adjacent first bead wires is 12 mm. The structural parameters of the second bead wire layer are exactly the same as those of the first bead wire layer. The radial spacing between the two bead wire layers, i.e., the shear band thickness, is 8 mm. The shear rubber layer is made of natural rubber and butadiene rubber blended at a mass ratio of 60:40, with a Shore hardness of 68 HA, a tensile strength of 20 MPa, an elongation at break of 450%, and a shear modulus of 1.5 MPa. During vulcanization, the shear rubber layer undergoes a chemical bonding reaction with the brass plating on the surface of the bead wires, achieving an adhesion strength of 25 MPa. The total thickness of the tread carcass layer is 16.2 mm, accounting for approximately 65% ​​of the total tread thickness. The width of the tread carcass layer in the tire width direction is 140 mm, accounting for approximately 78% of the total tread width. The distance between the edges of the carcass layer and the edges of the tread sidewalls is 20 mm. The inner transition rubber is located on the inner side of the tread skeleton layer, with a thickness of 0.8 mm. It is made of natural rubber with a Shore hardness of 75HA. The transition rubber is fixedly connected to the inner surface of the tread skeleton layer by vulcanization bonding. The flexible spoke section comprises 60 flexible spoke units, which are evenly distributed along the tire circumference. The circumferential angle between any two adjacent spoke units is 6 degrees. Each flexible spoke unit is manufactured using thermoplastic polyurethane elastomer material through injection molding, with a Shore hardness of 85A. The cross-sectional shape is rectangular, with a width of 8mm, a height of 6mm, and a radial length of 80mm. Under non-load conditions, the spoke unit initially tilts outward at a 15-degree angle. The outer end of the spoke unit has a pre-reserved cylindrical connecting boss structure with a diameter of 10mm and a length of 5mm. This boss is inserted into a pre-reserved connecting groove on the inner side of the tread portion and fixedly connected by vulcanizing adhesive. The inner end of the spoke unit is inserted into a connecting groove on the outer ring of the rim. The groove has a depth of 8mm, a width of 10mm, and a flat bottom. The inner end of the spoke is fixedly connected to the groove by vulcanizing adhesive. The rim body is made of aluminum alloy through casting process, with a radial thickness of 12mm and an axial width of 150mm. The inner ring of the rim body has 5 mounting holes, which are evenly distributed circumferentially. The circumferential angle between two adjacent mounting holes is 72 degrees. The diameter of each mounting hole is 12mm. The inner wall of the mounting hole is threaded for threaded connection with the bolt rod.The non-pneumatic tire is first manufactured by arranging the first bead wire layer on the surface of the forming drum with a circumferential spacing of 12 mm to form a first bead wire layer, then coating an 8 mm thick unvulcanized shear rubber on the surface of the first bead wire layer, then arranging a second bead wire layer, and then coating an unvulcanized rubber compound on the outer surface of the tire tread skeleton layer blank body and an unvulcanized rubber compound on the inner surface of the tire tread skeleton layer blank body after the tire tread skeleton layer blank body is manufactured. The entire tire tread portion blank body is molded by a vulcanization process in a vulcanization mold at a temperature of 165°C, a pressure of 1.8 MPa, and a time of 35 minutes. The flexible spoke portion is manufactured by an injection molding process, and the connection between the spoke unit and the tire tread portion and the rim portion is achieved by a vulcanization adhesive, and the adhesive is cured at a temperature of 120°C for 20 minutes to achieve the final strength. When the non-pneumatic tire bears a radial load of 300 kg, the radial deformation of the tire tread portion at the joint area is 1.5 mm, the flexible spoke unit below the joint area bears a compression load and bends and deforms inwardly by about 18 degrees, the two bead wire layers in the tire tread skeleton layer bend and deform cooperatively at the joint area, the shear rubber layer between the adjacent bead wire layers bears a shear strain of about 35%, and the shear rubber layer limits the excessive bending of the bead wire layer through a shear constraint mechanism to maintain the overall stiffness of the tire tread portion and avoid local collapse. The tire is suitable for urban road driving conditions, the design speed is 80 km / h, and the design load is 400 kg.

[0075] The following provides Embodiment 2 of the present application: This embodiment is improved on the basis of Embodiment 1, and the main upgrade is to increase the number of tire tread skeleton layers to improve the carrying capacity. The total thickness of the tire tread portion of the non-pneumatic tire is increased to 32 mm, and the tire tread skeleton layer is upgraded from the original two bead wire layers to four bead wire layers to form three shear band structures. The first bead wire layer, the second bead wire layer, the third bead wire layer, and the fourth bead wire layer are all made of bead wires with a diameter of 1.8 mm, a tensile strength of 2400 MPa, and a bending stiffness of 280 N· The surface is coated with a 0.15-micron thick copper plating. The first shear band between the first and second bead wire layers is 10 mm thick, the second shear band between the second and third bead wire layers is 9 mm thick, and the third shear band between the third and fourth bead wire layers is 9 mm thick. All three shear rubber layers are made of a blend of natural rubber and butadiene rubber with a Shore hardness of 72 HA and a shear modulus of 1.8 MPa. The total thickness of the tread skeleton layer is increased to 28.4 mm, accounting for 89% of the total tread thickness, while the thickness of the outer tread rubber layer is reduced to 3.6 mm to maintain a reasonable range for the total tread thickness. The number of spoke units in the flexible spoke section has increased to 80, the circumferential angle between adjacent spoke units has been reduced to 4.5 degrees, the cross-sectional width of each spoke unit has increased to 10 mm, the cross-sectional height has increased to 8 mm, while the radial length remains unchanged at 80 mm. The Shore hardness of the spoke units has been increased to 90A to match the higher tread stiffness, and the radial stiffness of the spoke units has been correspondingly increased to 280 N / mm. The radial thickness of the rim body has been increased to 15 mm to withstand greater load transmission, and the number of connecting grooves on the outer rim has increased to 80 to match the number of spokes. This improved non-pneumatic tire has a radial deformation of less than 1.8 mm in the tread portion when subjected to a radial load of 450 kg. The four-layer bead steel wire layer achieves stronger synergistic load-bearing capacity through three sets of shear band structures. The strain value of the shear rubber layer under the maximum shear strain state is about 40%. The energy dissipation effect of the multi-layer shear band structure is more significant, thereby effectively reducing the vibration amplitude of the tire during rolling. This tire is suitable for light freight vehicles or passenger cars that require higher load-bearing capacity. The design speed is 100 km / h and the design load is 550 kg.

[0076] The following is Embodiment 3 of the present invention: This embodiment is an improvement in another direction based on Embodiment 1, mainly optimized by enhancing the cushioning performance of the flexible spoke portion to improve driving comfort. The total thickness of the tread portion of this non-pneumatic tire remains unchanged at 25mm, and the tread carcass layer still adopts a two-layer bead wire structure, but the diameter of the bead wire is reduced to 1.4mm, the tensile strength is 2000MPa, and the bending stiffness is 210N·m. The shear band thickness was adjusted to 7mm, the Shore hardness of the shear rubber layer was reduced to 62HA, and the shear modulus was reduced to 1.2MPa to provide better shear deformation energy absorption capacity. The number of spoke units in the flexible spoke section remained unchanged at 60, but the material of each spoke unit was changed to thermoplastic polyester elastomer, the Shore hardness was reduced to 78A, and the cross-sectional shape was changed to an I-shaped section to provide better bending flexibility while maintaining sufficient radial stiffness. The web width of the I-shaped section was 4mm, the web height was 6mm, the width of the upper and lower flanges was 8mm, and the thickness of the flanges was 2mm. The radial length of the spoke unit was increased to 95mm, the initial tilt angle was increased to 18 degrees, and the radial stiffness of the spoke unit was reduced to 120N / mm. A transition layer is added between the inner side of the tread portion and the outer end of the flexible spoke portion. This transition layer is made of a rubber material with a gradient hardness; the Shore hardness is 75HA on the side closer to the tread portion and 80A on the side closer to the flexible spoke portion. The thickness of the transition layer is 8mm. Forty transition reinforcing cords, made of polyester fiber with a diameter of 1.2mm, are embedded within the transition layer along the tire circumference. The circumferential spacing between adjacent cords is 8mm. This transition layer is used to mitigate the abrupt change in stiffness between the tread portion and the flexible spoke portion and to improve stress distribution. Sidewall reinforcement layers are provided at the two sidewall locations of the tread portion. These reinforcement layers are made of nylon cord fabric with a thickness of 2.5mm and a width of 30mm along the tire axial direction. The sidewall rubber layer is made of a 50:50 blend of natural rubber and butyl rubber, with a Shore hardness of 60HA and a thickness of 8mm. This improved non-pneumatic tire exhibits increased radial deformation of the tread portion to 2.2 mm under a 300 kg radial load. The increased bending deformation of the flexible spoke units provides better cushioning and energy absorption. The shear strain of the shear rubber layer is approximately 30%, and the lower shear modulus makes the viscoelastic damping effect of the shear rubber layer more pronounced during deformation. This tire is suitable for passenger cars with high requirements for driving comfort or special vehicles requiring good shock absorption performance. The design speed is 70 km / h, and the design load is 350 kg.

[0077] It should be noted that the variables involved in this invention are explained in detail in Table 1.

[0078] Table 1. Variable Explanation Table

[0079]

[0080] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A non-pneumatic tire with a bead wire skeleton tread, characterized in that, The tire structure comprises the tread, flexible spokes, and rim. The tread is the outermost layer of the entire tire structure, the flexible spokes are located inside the tread, and the rim is located inside the flexible spokes. The tread and rim are connected through the flexible spokes for load transfer and structural connection. An embedded tread skeleton layer contains at least two layers of bead wires arranged continuously along the tire circumference. Shear rubber layers are filled between the bead wire layers to form a shear band structure. This shear band structure provides shear constraint to the intermediate shear rubber layer through the two bead wire layers, thereby improving the stiffness and overall rigidity of the tread. Simultaneously, it utilizes the tire… The superior bending stiffness of the coil wire compared to multi-strand cord wire enhances the tread's resistance to deformation and ensures the load-bearing capacity of the non-pneumatic tire. The tread consists of an outer tread compound, a tread carcass layer, and an inner transition compound. The outer tread compound is located on the outermost side of the tread and is in direct contact with the ground, while the inner transition compound is located on the inner side of the tread carcass layer and is connected to the flexible spokes. The flexible spokes consist of multiple flexible spoke units, which are evenly distributed along the tire circumference between the inner surface of the tread and the outer surface of the rim. The rim consists of a rim body, an inner rim ring, and an outer rim ring. The outer surface of the outer rim ring is fixedly connected to the inner end of the flexible spoke units.

2. The non-pneumatic tire with a bead-wire skeleton tread according to claim 1, characterized in that, The tread carcass layer includes a first bead wire layer, a second bead wire layer, and a first shear rubber layer located between the first bead wire layer and the second bead wire layer. The first bead wire layer is composed of multiple first bead wires arranged in parallel along the tire circumference, and the second bead wire layer is composed of multiple second bead wires arranged in parallel along the tire circumference. The arrangement direction of the first bead wires and the second bead wires is consistent and they both extend along the tire circumference. The first shear rubber layer fills the space between the first bead wire layer and the second bead wire layer and forms a chemical bond with the surface coatings of the first bead wires and the second bead wires through a vulcanization process.

3. The non-pneumatic tire with a bead-wire skeleton tread according to claim 2, characterized in that, The diameter of the first bead wire ranges from 1.0 mm to 3.0 mm. The base material of the first bead wire is high carbon steel. The tensile strength of the first bead wire ranges from 1800 MPa to 2800 MPa. The bending stiffness of the first bead wire ranges from 180 N·mm² to 350 N·mm². The surface of the first bead wire is coated with a metal layer, which is selected from brass, copper, or bronze, and the thickness of the metal layer ranges from 0.08 μm to 0.2 μm. The material characteristics, diameter specifications, tensile strength, bending stiffness, and surface coating characteristics of the second bead wire are consistent with those of the first bead wire.

4. The non-pneumatic tire with bead wire skeleton tread according to claim 3, characterized in that, The radial spacing between the first and second bead wire layers is defined as the first shear band thickness, which ranges from 3 mm to 15 mm. The thickness of the first shear rubber layer is equal to the first shear band thickness. The center-to-center distance between two adjacent first bead wires within the first bead wire layer is defined as the first circumferential spacing, which ranges from 10 mm to 20 mm. The center-to-center distance between two adjacent second bead wires within the second bead wire layer is defined as the second circumferential spacing, which also ranges from 10 mm to 20 mm.

5. The non-pneumatic tire with a bead-wire skeleton tread according to claim 4, characterized in that, The two ends of the first bead wire extend along the tire axis beyond the width boundary of the tread portion, with an extension length ranging from 8mm to 12mm. The extended ends of the first bead wire are bent downward to form a hook-shaped fixing structure. The hook-shaped fixing structure is embedded inside the sidewall rubber layer of the tread portion. The bending angle of the hook-shaped fixing structure ranges from 90 degrees to 180 degrees, and the bending radius of the hook-shaped fixing structure ranges from 2mm to 8mm.

6. The non-pneumatic tire with a bead-wire skeleton tread according to claim 5, characterized in that, The tread carcass layer also includes a third bead wire layer, a fourth bead wire layer, a second shear rubber layer, and a third shear rubber layer. The third bead wire layer is located inside the second bead wire layer, and the second shear rubber layer fills the space between the second and third bead wire layers. The fourth bead wire layer is located inside the third bead wire layer, and the third shear rubber layer fills the space between the third and fourth bead wire layers. The thickness of the second shear rubber layer ranges from 3 mm to 15 mm, and the thickness of the third shear rubber layer also ranges from 3 mm to 15 mm. The total number of bead wire layers in the tread carcass layer ranges from 2 to 10, and the proportion of the tread carcass layer to the total thickness of the tread portion ranges from 50% to 90%.

7. The non-pneumatic tire with a bead-wire skeleton tread according to claim 6, characterized in that, There is a dimensional ratio between the thickness of the first shear band and the diameter of the first bead wire, with a ratio ranging from 2.0 to 8.

0. When the ratio is less than 2.0, the thickness of the shear rubber layer is too thin, resulting in excessive shear strain and easy tearing failure of the rubber layer. When the ratio is greater than 8.0, the thickness of the shear rubber layer is too thick, resulting in weakened shear constraint and inability to effectively improve tread stiffness. There is also a dimensional ratio between the first circumferential spacing and the diameter of the first bead wire, with a ratio ranging from 5.0 to 12.

0. When the ratio is less than 5.0, the spacing between adjacent bead wires is too small, resulting in excessive bead wire density and increased tread weight. When the ratio is greater than 12.0, the spacing between adjacent bead wires is too large, resulting in insufficient local tread stiffness and easy local indentation under load.

8. The non-pneumatic tire with a bead-wire skeleton tread according to claim 7, characterized in that, There is a thickness ratio between the total thickness of the tread carcass layer and the total thickness of the tread portion. The total thickness of the tread carcass layer is equal to the product of the thickness ratio coefficient and the total thickness of the tread portion. The thickness ratio coefficient ranges from 0.50 to 0.

90. When the thickness ratio coefficient is 0.50, it means that the tread carcass layer accounts for 50% of the tread thickness, thus leaving a thicker outer tread rubber layer to provide good grip performance. When the thickness ratio coefficient is 0.90, it means that the tread carcass layer accounts for 90% of the tread thickness, thus maximizing tread stiffness, but the outer tread rubber layer is thinner, resulting in a shorter wear life.

9. The non-pneumatic tire with a bead-wire skeleton tread according to claim 8, characterized in that, There is a stiffness matching relationship between the radial stiffness of the flexible spoke unit and the bending stiffness of the tread carcass layer. The radial stiffness of the flexible spoke unit is equal to the product of the stiffness matching coefficient and the bending stiffness of the tread carcass layer divided by the number of flexible spoke units by 100. The value of the stiffness matching coefficient ranges from 0.3 to 1.

2. When the stiffness matching coefficient is small, the radial stiffness of the flexible spoke unit is relatively low, thus providing better cushioning performance but limiting the load-bearing capacity. When the stiffness matching coefficient is large, the radial stiffness of the flexible spoke unit is relatively high, thus improving the load-bearing capacity but reducing the cushioning performance.

10. The non-pneumatic tire with a bead wire skeleton tread according to claim 9, characterized in that, There is an angular deformation relationship between the initial tilt angle of the flexible spoke unit and the radial deformation of the non-pneumatic tire. The radial deformation of the non-pneumatic tire is equal to the difference between the radial length of the flexible spoke unit and the cosine of the initial tilt angle, plus the product of the deformation correction factor and the design load divided by the radial stiffness of the flexible spoke unit. The value range of the deformation correction factor is 0.8 to 1.

2. When the initial tilt angle is large, the contribution of geometric deformation increases, resulting in a larger radial deformation. When the radial stiffness of the flexible spoke unit is small, the elastic deformation under the same load increases, resulting in a larger radial deformation.

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