CN114228403A

CN114228403A - Polyurethane spoke for non-pneumatic tire and preparation method thereof

Info

Publication number: CN114228403A
Application number: CN202111365641.3A
Authority: CN
Inventors: 黄亚南; 杨小牛; 赵晓礼
Original assignee: Huangpu Institute of Materials
Current assignee: Huangpu Institute of Materials
Priority date: 2021-11-17
Filing date: 2021-11-17
Publication date: 2022-03-25
Anticipated expiration: 2041-11-17
Also published as: CN114228403B

Abstract

The invention belongs to the technical field of non-pneumatic tires, and discloses a polyurethane spoke for a non-pneumatic tire and a preparation method thereof. The polyurethane spoke for a non-pneumatic tire of the present invention includes a polyurethane elastomer and a reinforcing material; the reinforcing material comprises a resin fiber composite sheet; the resin fiber composite sheet comprises a thermosetting resin and fibers; the resin fiber sheet has a fiber density in the radial direction that is greater than the fiber density in the vertical direction. The polyurethane spoke can be integrally formed by mould pressing or pouring, the forming method is simple and easy to implement, and the comprehensive performance of the spoke can be comprehensively balanced and coordinated.

Description

Polyurethane spoke for non-pneumatic tire and preparation method thereof

Technical Field

The invention relates to the technical field of non-pneumatic tire spokes, in particular to a polyurethane spoke for a non-pneumatic tire and a preparation method thereof.

Background

In recent years, with the increase in vehicle speed, the expansion of driving environment, and the increase in safety requirements of people, limitations of conventional pneumatic tires have been gradually developed, such as the need to maintain proper internal air pressure for regular maintenance; the manufacturing process is complex; the tire is easy to burst, and a series of fatal accidents can be caused after the tire bursts. Accordingly, as non-pneumatic tires are produced, the research on non-pneumatic tires by companies such as michelin, pulison and goospecific has entered the experimental testing stage, and gradually shifted from the bottom bearing mode of compression deformation of the elastic filling material to the top bearing mode of extension deformation depending on the elastic structure of the support, while the domestic generation of mechanical elastic rings (chinese patent document CN 206589557U), V-shaped support structures of negative poisson's ratio structure (chinese patent document CN 106739828B), thermoplastic polyurethane materials of regular hexagon 3D printing, and elastic metal mesh, etc., has replaced the air in pneumatic tires, resulting in a series of non-pneumatic tires.

The load bearing of a conventional pneumatic tire is mainly dependent on the tire internal air and the carcass itself, which as a whole exhibits a stretched structure. The non-pneumatic tire is a structural load-bearing tire, and in addition to the requirements of rigidity and strength for the tread to be in contact with the ground, the spokes (support structures) connecting the tread and the hub transmit the load to the tread and the hub on the one hand and also need to bear a part of the load by themselves, and on the other hand, need to ensure operability and riding comfort similar to the internal air pressure of the pneumatic tire, and have appropriate radial rigidity.

The structure, performance and preparation process of the spoke are important in a non-pneumatic tire, the spoke materials such as rubber (Chinese patent document CN 104302488B), polyurethane elastomer (Chinese patent documents CN 108081872A, CN 110770038A and CN 111051079A, CN 111989226A) and engineering plastics (CN 102582365A) exist at present, the spoke materials adopt rubber as a base material, the different parts of the spoke can be made of rubber with different properties, the rubber with different property formulas is firstly semi-vulcanized into various parts, then different parts are assembled and uniformly activated, the material can flexibly change the performance of different parts of the spoke, the reinforced rubber is made of rubber with different properties according to the stress characteristics of different parts, the reinforced material can be placed at a required part according to the stress characteristics, the state of the reinforced material is not limited, and the reinforced rubber can be reinforced filler, reinforced cord fabric material and the like. However, the whole preparation process is distributed molding, assembly vulcanization and relatively complicated. The spoke made of the polyurethane elastomer and the engineering plastic material serving as the spoke base material can be integrally formed, the preparation process is simple and easy to implement, most of the reinforcing material of the spoke is chopped fibers or powder, and granular filler is uniformly dispersed in the base material and then integrally formed. However, the performance of each part of the spoke is the same, and the added reinforcing material cannot meet the performance of the whole spoke and cannot individually reinforce the part of the spoke which needs to be reinforced specifically. If the strength of the part of the spoke which bears the load is high, the load is required to be transmitted to the tread and the hub while bearing the load, and the requirements of the part which does not bear the load on the base material are high rebound resilience, fatigue resistance and tear resistance, and the rebound resilience, the fatigue resistance and the tear resistance are reduced along with the increase of the added reinforcing material.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provide a polyurethane spoke for a non-pneumatic tire and a preparation method thereof so as to overcome the technical problems that the casting molding of spoke materials is complicated and the performances of all aspects cannot be comprehensively balanced and coordinated in the prior art.

In order to achieve the purpose, the technical scheme adopted by the invention is as follows:

in a first aspect, the present invention provides a polyurethane spoke for a non-pneumatic tire, comprising a polyurethane elastomer and a reinforcing material;

the reinforcing material comprises a resin fiber composite sheet;

the resin fiber composite sheet comprises a thermosetting resin and fibers;

the resin fiber sheet has a fiber density in the radial direction that is greater than the fiber density in the vertical direction.

As a preferable embodiment of the polyurethane spoke for the non-pneumatic tire, the Shore D hardness of the polyurethane spoke is 20-50, the compression modulus is 12-55, and the glass transition temperature is lower than 50 ℃.

Furthermore, the Shore D hardness of the polyurethane spoke is 33-43, the compression modulus is 19-39, and the glass transition temperature is-42-35 ℃.

As a preferable embodiment of the polyurethane spoke for non-pneumatic tires of the present invention, the raw materials of the polyurethane elastomer include:

soft segments with the molecular weight of 650-4000, hard segments, a chain extender and a cross-linking agent;

the molar ratio of the soft segment to the hard segment is 1: 2-3;

the molar ratio of the chain extender to the cross-linking agent is 95-98: 2-5;

the R value of the raw material system is 1-1.05.

Preferably, the molecular weight of the soft segment is 1000-2000.

Preferably, the soft segment is at least one of polyether polyol, polyester polyol, polyolefin polyol, vegetable oil polyol and amine-terminated polyether.

As a preferable embodiment of the polyurethane spoke for a non-pneumatic tire of the present invention, the thermosetting resin is at least one of epoxy resin, polyester, and polyurethane.

As a preferable embodiment of the polyurethane spoke for non-pneumatic tires of the present invention, the glass transition temperature of the thermosetting resin is more than 110 ℃. Preferably from 150 ℃ to 123 ℃.

In a preferred embodiment of the polyurethane spoke for a non-pneumatic tire according to the present invention, the fiber is at least one of carbon fiber, glass fiber, aramid fiber, and polyester fiber.

As a preferable embodiment of the polyurethane spoke for a non-pneumatic tire of the present invention, the content of the fiber in the resin fiber composite sheet is 50% to 70%.

As a preferable embodiment of the polyurethane spoke for non-pneumatic tires of the present invention, the reinforcing material further includes a hank plane structure.

Preferably, the skein plane structure includes at least one of a two-dimensional woven fabric, a non-woven fabric, and a knitted fabric.

More preferably, the two-dimensional woven fabric is at least one of nylon fabric and polyester fabric.

In a second aspect, the present invention provides a method for producing the above-described polyurethane spoke for non-pneumatic tires:

and (3) placing the reinforced material in a preheated forming die, injecting the polyurethane elastomer at the temperature of 100-110 ℃, and casting or pressing for forming.

Compared with the prior art, the invention has the beneficial effects that:

according to the polyurethane spoke, the integral molding of the spoke can be integrally molded through mould pressing or pouring, the molding method is simple and easy to implement, the preparation process is rapid, and the polyurethane spoke is suitable for large-scale production; secondly, reinforcing materials with specific performance can be added at specific positions needing to be reinforced, for example, specific reinforcing can be carried out at specific positions bearing load in the spoke without influencing the performance of other parts, namely, the comprehensive performance of the spoke can be comprehensively balanced and coordinated; and thirdly, the filler is not only limited to granular or split charging, but also whether the reinforcing filler is uniformly mixed in the polyurethane matrix and is compatible with the polyurethane matrix is not required to be considered.

Drawings

Fig. 1 is a front view schematically showing the structure of a spoke mold for a non-pneumatic tire according to example 2;

fig. 2 is a left side structural view of the spoke mold for a non-pneumatic tire of example 2;

fig. 3 is a schematic top structural view of a spoke mold for a non-pneumatic tire according to example 2;

fig. 4 is one of schematic perspective views of a spoke mold for a non-pneumatic tire according to example 2;

fig. 5 is a second perspective view of the spoke mold for a non-pneumatic tire according to example 2;

fig. 6 is an exploded view of the structure of a spoke mold for a non-pneumatic tire according to example 2;

FIG. 7 is a schematic structural view of a spoke mold for a non-pneumatic tire according to example 2, with the pressure plate, the left projecting strip, and the right projecting strip removed;

FIG. 8 is a schematic structural view of the spoke mold for a non-pneumatic tire of example 2 with the pressure plate, the left projecting clip strip, the right projecting clip strip, and the right side plate removed;

in FIGS. 1 to 8, 1 is a pressing plate; 2. the device comprises a base, 21, a left strip, 211, a left convex clamping strip, 212, a left gasket, 213, a left concave clamping strip, 22, a right strip, 221, a right convex clamping strip, 222, a right gasket, 223, a right concave clamping strip, 23, a front limiting strip, 231, a front fixing block, 24, a rear limiting strip, 241 and a rear fixing block; 3. a left side plate; 4. a right side plate; 5. a bolt; 6. a handle.

FIG. 9 is a schematic spoke construction of the polyurethane spoke of example 3;

FIG. 10 is a schematic representation of the polyurethane spoke construction of example 3;

FIG. 11 is a compression cycle curve for a polyurethane spoke according to example 3;

in fig. 11, #1 to #5 represent five compression cycles in the test.

FIG. 12 is a schematic spoke construction of the polyurethane spoke of example 4;

FIG. 13 is a compression cycle curve for the polyurethane spoke of example 4;

FIG. 14 is one of the spoke construction schematics of the polyurethane spoke of example 5;

FIG. 15 is a second schematic spoke construction for the polyurethane spoke of example 5;

in fig. 9, 10, 12, 14, 15, 7, a resin fiber sheet; 8. a polyurethane elastomer; 9. polyester fabric; 10. a ply.

Detailed Description

To better illustrate the objects, aspects and advantages of the present invention, the present invention will be further described with reference to specific examples. It will be understood by those skilled in the art that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

The test methods used in the examples are all conventional methods unless otherwise specified; the materials, reagents and the like used are commercially available unless otherwise specified.

Example 1: polyurethane spoke for non-pneumatic tire

The polyurethane spoke for a non-pneumatic tire is made of a composite sheet of a polyurethane elastomer and a resin fiber.

The polyurethane elastomer is a thermosetting polyurethane elastomer material, the soft segment of the polyurethane elastomer can be selected from polyether polyol, polyester polyol, polyolefin polyol, vegetable oil polyol, amine-terminated polyether and the like, wherein the molecular weight of the soft segment polyol is 650-4000; the Shore D hardness of the polyurethane spoke is 20-50, the compressive modulus is 12-55 (the compressive modulus is obtained by calculation within the range of 1% -5% of strain), the glass transition temperature is lower than 50 ℃, and the preferred temperature is lower than 25 ℃.

The resin fiber composite sheet is a reinforcing material in the polyurethane spoke, bears load, transmits the load to the spoke and the tire tread, and is distributed at a specific position of the polyurethane spoke. The fiber can be selected from carbon fiber, glass fiber, aramid fiber and polyester fiber, and carbon fiber and glass fiber are preferred; the direction of the fiber in the plate can be unidirectional distribution or bidirectional distribution, and the fiber layers can be simply stacked or interwoven.

The force state of the polyurethane spoke in the tire is analyzed, the spoke is mainly subjected to tensile or compressive force during the running process of the tire, the whole body is subjected to a torsional force during cornering, which requires the resin fiber composite sheet in the polyurethane spoke to have certain strength in both directions, but the forces in the two directions are different, the force of stretching or compressing during running determines the radial rigidity of the spoke and further determines the bearing capacity of the tire, the force of torsion determines the lateral rigidity, the proper lateral rigidity provides better maneuverability of the tire, and the polyurethane elastomer has certain strength, therefore, the fiber density of the resin fiber sheet in the polyurethane spoke along the radial direction is greater than that of the resin fiber sheet perpendicular to the radial direction, and the resin fiber sheet can be used for adapting to the motion stress state of the spoke.

The resin is thermosetting resin, the thermosetting resin can be epoxy resin, polyester, polyurethane and the like, and the epoxy resin is preferred; the epoxy resin with the glass transition temperature of more than 110 ℃ after crosslinking is preferred, because the temperature used in the casting molding or compression molding of the polyurethane is 100-110 ℃, and the glass transition temperature ensures that the composite sheet material cannot become soft and cause macroscopic damage when being subsequently compounded with the polyurethane.

The thermosetting resin and the fibers of the resin fiber composite sheet are bonded together by means of lamination or pultrusion.

Example 2: spoke mould for non-pneumatic tire

(1) The spoke mold for the non-pneumatic tire is shown in figures 1-8 and comprises a pressing plate 1, a base 2, a left side plate 3 and a right side plate 4;

the left edge strip 21 is detachably arranged at the left end of the base 2, and the left edge strip 21 sequentially comprises a left convex clamping strip 211, a left gasket 212 and a left concave clamping strip 213 from top to bottom; the shapes of the joint surfaces among the left convex clamping strip 211, the left gasket 212 and the left concave clamping strip 213 are matched; the left concave clamping strip 213 is fixed on the base 2 through a bolt 5;

the right side strip 22 is detachably arranged at the right end of the base 2, and the right side strip 22 sequentially comprises a right convex clamping strip 221, a right gasket 222 and a right concave clamping strip 223 from top to bottom; the shapes of the connection surfaces among the right convex clamping strip 221, the right gasket 222 and the right concave clamping strip 223 are matched; the right concave clamping strip 223 is fixed on the base 2 through a bolt 5;

the upper front part of the base 2 is detachably provided with a front limiting strip 23, and the left end and the right end of the front limiting strip 23 are respectively detachably provided with a front fixing block 231; the front fixing block 231 is fixed on the base 2 through a bolt 5;

a rear limiting strip 24 is detachably arranged at the upper rear part of the base 2, and rear fixing blocks 241 are respectively detachably arranged at the left end and the right end of the rear limiting strip 24; the rear fixing block 241 is fixed on the base 2 through a bolt 5;

the pressure plate 1 is fixed on the front limit strip 23 and the rear limit strip 24 through bolts 5; the shapes of the connecting surfaces among the pressure plate 1, the front limit strip 23, the rear limit strip 24 and the base 2 are matched;

the left side plate 3 and the right side plate 4 are respectively fixed on the left edge strip 21 and the right edge strip 22 through bolts 5;

and handles 6 are fixedly arranged on the pressing plate 1, the left side plate 3, the right side plate 4, the front limit strip 23 and the rear limit strip 24.

(2) The use method of the spoke mold for the non-pneumatic tire comprises the following steps:

1) assembling the base 2, the left concave clamping strip 213 and the right concave clamping strip 223;

2) the left pad 212 and the right pad 222 are respectively placed at the corresponding positions of the left concave clamping strip 213 and the right concave clamping strip 223;

placing the resin fiber sheet on the left gasket 212 and the right gasket 222, respectively placing the left convex clamping strip 211 and the right convex clamping strip 221 on the resin fiber sheet, and assembling the front limiting strip 23 and the rear limiting strip 24; clamping the resin fiber sheet in the front fixing block 231, the rear fixing block 241, the left gasket 212 and the right gasket 222, assembling the pressing plate 1, and fixing the pressing plate with the bolts 5; fixing the resin fiber sheet;

the heights of the left concave clamping strip 213 and the right concave clamping strip 223 are higher than that of the base 2, and the heights can be adjusted according to the positions of the resin fiber sheets in the polyurethane elastomer;

4) assembling a left side plate 3 and a right side plate 4, and preheating the mold in a vulcanizing machine at 100-110 ℃ for about 30 minutes;

5) opening the pressing plate 1, pouring the polyurethane elastomer into the mold, closing the pressing plate 1 after the polyurethane elastomer is initially cured, and pressurizing (10MPa) for 1 hour;

6) releasing pressure, namely unscrewing and taking down screws of the left side plate 3 and the right side plate 4 after the die is taken down, prying the die by using a crowbar, prying the pressing plate 1, and taking down the cured polyurethane spoke; the length of the resin fiber sheet of the polyurethane spoke at this time is longer than that of the polyurethane spoke, and the resin fiber sheet is cut to a desired length.

The space formed by the pressure plate 1, the front limit strip 23, the rear limit strip 24, the left strip 21, the right strip 22 and the base 2 of the spoke mold for the non-pneumatic tire is the main body part of the polyurethane spoke.

The left edge strip 21 and the right edge strip 22 are used for limiting or fixing the position of the reinforcing material (resin fiber sheet) in the main body part, so that the resin fiber sheet is positioned in the middle of the polyurethane elastomer of a specific part after the resin fiber sheet is poured by the polyurethane elastomer, and the resin fiber sheet is completely covered and wrapped by the polyurethane elastomer in the polyurethane spoke.

The resin fiber sheet is clamped in the front fixing block 231, the rear fixing block 241, the left gasket 212 and the right gasket 222, and after the resin fiber sheet is placed, a space formed by the resin fiber sheet, the left gasket 212, the right gasket 222, the left concave clamping strip 213, the right concave clamping strip 223 and the base 2 can be used as a place for placing a reinforcing material at the middle part of the polyurethane spoke, for example, a reinforced woven material such as nylon cloth or polyester cloth, and the two-dimensional woven material can be suspended and positioned in the polyurethane spoke.

When the widths of the two resin fiber sheets in the spoke are not uniform, the left pad 212 and the right pad 222 are asymmetric. The position of the resin fiber sheet in the polyurethane elastomer is limited and fixed by the front fixing block 231, the rear fixing block 241, the left gasket 212 and the right gasket 222, and if the position of the resin fiber sheet needs to be changed, the size or the thickness of the front fixing block 231, the rear fixing block 241, the left gasket 212 and the right gasket 222 can be easily changed.

This spoke mould for non-pneumatic tire can realize placing resin fiber sheet in the specific position of polyurethane spoke and not influence the performance of polyurethane elastomer itself, through the method of location reinforcing material, has realized that resin fiber composite sheet or other reinforcing material are unsettled and have been placed specific position in the polyurethane spoke, and the position can not change in compression molding or casting forming process.

Example 3: polyurethane spoke for non-pneumatic tire

The preparation method of the polyurethane spoke for the non-pneumatic tire comprises the following steps:

(1) reinforcing materials: glass fiber-epoxy resin composite board

The plate is prepared by laminating reticular glass fiber cloth (warp density is 110 and weft density is 60) and epoxy resin, wherein the content of the glass fiber is 70 wt%, the glass transition temperature of the epoxy resin is 123 ℃, the sizes of the two plates are 200 x 42mm and 200 x 46mm, the resin fiber sheet is polished, cleaned, brushed with an adhesive, then the solvent is removed at 80 ℃, and the plate is dried for later use.

The thickness of the resin fiber sheet is 1.0mm, the total thickness of the designed polyurethane spoke is 2.26mm, as shown in fig. 9, the resin fiber sheet is positioned in the middle of the spoke, the upper part and the lower part of the spoke are wrapped by polyurethane elastic bodies, and the height of the left concave clamping strip 213 and the height of the right concave clamping strip 223 of the mold are 0.5mm higher than that of the base 2.

The reinforcing material was placed on the left pad 212 and the right pad 222 in the spoke mold for a non-pneumatic tire of example 2, the mold was assembled after being limited by the left side band 21 and the right side band 22, and the resultant was placed on a vulcanizer at 110 ℃ to be preheated and insulated.

(2) Polyurethane elastomer

PTMEG (polytetrahydrofuran glycol) with the molecular weight of 2000 is used as a soft segment, MDI (diphenylmethane diisocyanate) is used as a hard segment, and the molar ratio of PTMEG/MDI is 1/3; BDO (1, 4-butanediol) is used as a chain extender, glycerol is used as a cross-linking agent, the mole ratio of BDO/glycerol is 98/2, and the R value of the whole system is 1.01.

And (2) carrying out vacuum-pumping drying on PTMEG at 120 ℃ for 2 hours to remove water, then cooling to 60 ℃, adding MDI (diphenyl-methane-diisocyanate) and PTMEG to react for 3 hours at 85 ℃ to obtain a polyurethane prepolymer, then adding BDO (diethylene glycol succinate) and glycerol to mix for 1 minute, pouring the mixture into a combined preheating mould after mixing uniformly, carrying out compression molding by using a vulcanizing machine after about 6 minutes, and carrying out pressure maintaining for about 60 minutes to obtain the polyurethane spoke.

The properties of the resulting polyurethane spokes were examined as follows:

the measurement of the glass transition temperature is obtained by DMA test, the measurement temperature range is-70-100 ℃, the temperature change rate is 5 ℃/min, the frequency is 1Hz, and the glass transition temperature is the temperature corresponding to the peak value of the loss factor Tan delta; the hardness is obtained by Shore hardness meter test according to the Shore hardness test method of GB 2411-1980 (1989); the compressive modulus was tested according to GB/T1041-.

The glass transition temperature of the polyurethane spoke is-42 ℃, the Shore D hardness is 33, and the compression modulus is 19 MPa.

(2) Based on a tire of specification 215/45N17, 64 such polyurethane spokes were prepared as shown in fig. 10. The angle of the prepared polyurethane spoke is 130 degrees, the angle of the spoke in the tire is 112 degrees, the sinking displacement of the pneumatic tire in the running process is 20mm, therefore, the total compression path of the spoke is 20mm, the compression and stretching speed is 25mm/min, the initial position is the angle of the spoke is 120 degrees, each sample is subjected to five compression cycles, the relation between the compression force and the displacement is measured, the sinking of the spoke is 20mm, the supporting force is about 530N, as can be seen from the compression cycle curve in fig. 11, the energy loss of the whole polyurethane spoke in the compression and recovery processes is less, the curves of multiple cycles are basically consistent, the hysteresis performance is excellent, the parts except for the resin fiber sheet in the polyurethane spoke have no filler, the low-hysteresis spoke is beneficial to transmitting the load, and the service life of the tire is prolonged.

Example 4: polyurethane spoke for non-pneumatic tire

(1) Reinforcing materials: carbon fiber-epoxy resin composite board

The plate is prepared by laminating reticular carbon fiber cloth (with the warp density of 90 and the weft density of 30) and epoxy resin. Wherein, the content of the carbon fiber is 50 wt%, the glass transition temperature of the epoxy resin is 150 ℃, the sizes of the two plates are 200X 32mm and 200X 36mm, the resin fiber sheet is polished, cleaned, brushed with an adhesive, then the solvent is removed at 80 ℃, and dried for standby.

The resin fiber sheet had a thickness of 1.0mm, and the designed polyurethane spoke had a total thickness of 2.26mm here. As shown in fig. 12, the reinforcing material resin fiber sheet was placed in the center of the spoke and wrapped with the urethane elastomer on the upper and lower sides, and the reinforcing material was placed on the left pad 212 and the right pad 222 in the spoke mold for a non-pneumatic tire of example 2, and was retained by the left edge band 21 and the right edge band 22.

(2) Reinforcing materials: two-dimensional knitted polyester fabric

The dimension of the two-dimensional woven terylene cloth is 200 multiplied by 45mm, wherein the density of warp threads in the terylene cloth is 25 plus or minus 1 threads/inch, the density of weft threads is 14 plus or minus 1 threads/inch, the thickness is 0.5mm, and the terylene cloth is used for reinforcing the middle part of a polyurethane spoke, is cut and is cleaned for standby.

As shown in fig. 12, the dacron cloth is placed outside the middle portion of the polyurethane spoke, the reinforcing material is placed on the left concave snap strip 213 and the right concave snap strip 223, the left pad 212 and the right pad 222 are pressed, the dacron cloth is fixed to be suspended and tightened, the resin fiber sheet is placed on the left pad 212 and the right pad 222, the reinforcing material is placed in a space formed by the resin fiber sheet, the left pad 212, the right pad 222, the left concave snap strip 213, the right concave snap strip 223 and the base 2, the assembling die is placed on a vulcanizing machine at 110 ℃ for preheating and heat preservation.

After the mold is assembled, the right convex clamping strip 221 or the left convex clamping strip 211, the resin fiber sheet, the left gasket 212 or the right gasket 222, the polyester fabric, the left concave clamping strip 213 or the right concave clamping strip 223 from top to bottom are seamlessly fitted.

(3) Polyurethane elastomer

PTMEG (polytetrahydrofuran glycol) with the molecular weight of 1000 is used as a soft segment, MDI (diphenylmethane diisocyanate) is used as a hard segment, the molar ratio of PTMEG/MDI is 1/2.7, BDO (1, 4-butanediol) is used as a chain extender, glycerol is used as a cross-linking agent, the molar ratio of BDO/glycerol is 95/5, and the R value of the whole system is 1.05.

And (2) carrying out vacuum-pumping drying on the PTMEG at 120 ℃ for 2 hours to remove water, then cooling to 60 ℃, reacting MDI (methylene diphenyl diisocyanate) and PTMEG at 80 ℃ for 2 hours to obtain a polyurethane prepolymer, then adding BDO (diethylene glycol succinate) and glycerol, mixing for 1 minute, pouring the mixture into a combined preheating mould after uniform mixing, carrying out compression molding by using a vulcanizing machine after about 6 minutes, and carrying out pressure maintaining for about 60 minutes to obtain the polyurethane spoke.

The properties of the resulting polyurethane spokes were examined as follows:

The glass transition temperature of the polyurethane spoke is 35 ℃, the Shore D hardness is 43, and the compression modulus is 39 MPa.

(4) Based on a tire of specification 215/45N17, 64 sheets of the polyurethane spokes were prepared, the angle of the spokes in the tire was 100 ℃, the angle of the spokes in the tire was 112 ℃, and the relationship between the compressive force and the displacement was measured, and it was found that the spokes were sunk by 20mm, and as can be seen from the compression cycle curve in fig. 13, the support force was 1589N. Under the same conditions, a polyurethane spoke without reinforcing material was prepared with a support force of 1375N.

The energy loss of the whole polyurethane spoke in the compression and recovery processes is less, the curves of multiple cycles are basically consistent, the hysteresis performance is excellent, the parts except the resin fiber sheet material in the polyurethane spoke are not filled with the filler, the low-hysteresis spoke is beneficial to transmitting load, and the service life of the tire is prolonged.

Example 5: polyurethane spoke for non-pneumatic tire

The difference from the embodiment 3 is that:

as shown in fig. 14, when the polyurethane spoke has a complicated shape, the mold is designed as a casting mold, and after fixing the reinforcing material, the reinforcing material is directly cast by a casting machine.

As shown in fig. 15, when the polyurethane spoke has an irregular shape, the mold is designed as a casting mold, and after the reinforcing material and the ply are fixed, casting molding is directly performed by using a casting machine.

And (3) adopting a polyurethane prepolymer during casting, taking the chain extender and the cross-linking agent as a material B, taking the prepolymer as a material A, mixing the material A and the material B (lasting for 2 minutes) by using a casting machine, adding the mixture into a mold, and after the casting is finished, keeping the mixture in the forming mold at 80 ℃ for 2 hours and then taking out the mixture to obtain the polyurethane/polyurethane composite material.

Finally, it should be noted that the above embodiments are only used for illustrating the technical solutions of the present invention and not for limiting the protection scope of the present invention, and although the present invention is described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that modifications or equivalent substitutions can be made on the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A polyurethane spoke for a non-pneumatic tire, characterized by comprising a polyurethane elastomer and a reinforcing material;

the reinforcing material comprises a resin fiber composite sheet;

the resin fiber composite sheet comprises a thermosetting resin and fibers;

2. A polyurethane spoke according to claim 1 for a non-pneumatic tire having a Shore D hardness of 20 to 50, a compressive modulus of 12 to 55, and a glass transition temperature of less than 50 ℃.

3. The polyurethane spoke according to claim 2, wherein the polyurethane spoke has a Shore D hardness of 33 to 43, a compressive modulus of 19 to 39, and a glass transition temperature of-42 ℃ to 35 ℃.

4. The polyurethane spoke according to claim 1, wherein the polyurethane elastomer is prepared from the following raw materials:

the molar ratio of the soft segment to the hard segment is 1: 2-3;

the molar ratio of the chain extender to the cross-linking agent is 95-98: 2-5;

the R value of the raw material system is 1-1.05.

5. The polyurethane spoke according to claim 4, wherein the soft segment is at least one of polyether polyol, polyester polyol, polyolefin polyol, vegetable oil polyol, and amine-terminated polyether.

6. The polyurethane spoke according to claim 1, wherein the thermosetting resin is at least one of epoxy resin, polyester, and polyurethane.

7. The polyurethane spoke according to claim 1, wherein the thermosetting resin has a glass transition temperature of more than 110 ℃.

8. The polyurethane spoke according to claim 1, wherein the fiber is at least one of carbon fiber, glass fiber, aramid fiber, and polyester fiber.

9. The polyurethane spoke according to claim 1, wherein the resin fiber composite sheet has a fiber content of 50% to 70%.

10. The polyurethane spoke according to claim 1, wherein the reinforcement material further includes a twisted yarn planar form.

11. The polyurethane spoke according to claim 10, wherein the skein fabric includes at least one of a two-dimensional woven fabric, a non-woven fabric, and a knitted fabric.

12. The polyurethane spoke according to claim 1, wherein the two-dimensional woven fabric is at least one of nylon fabric and polyester fabric.

13. The method for preparing a polyurethane spoke for a non-pneumatic tire as claimed in any one of claims 1 to 12, wherein the reinforcement material is placed in a preheated forming mold, injected into a polyurethane elastomer at a temperature of 100 ℃ to 110 ℃, and cast or pressed to form the polyurethane spoke.