High-durability tire

Abstract

The invention relates to the technical field of tires, and discloses a high-durability tire which is characterized in that a tire body turn-up end part and a chafer end part are respectively provided with a covering piece for covering the corresponding tire body turn-up end part and the chafer end part, and the outer sides of the tire body turn-up end part and the chafer end part are respectively provided with a rubber supporting layer. According to the covering part, the bonding force between the tire body turn-up end and the adjacent rubber layer and between the tire chafer end and the adjacent rubber layer can be increased, separation is restrained, the durability of the tire is improved, the service life of the tire is prolonged, heat accumulated at the tire body rolling end can be rapidly dissipated, and damage to the tire body rolling end due to heat generation is reduced; the arranged rubber supporting layer can be further matched with the covering part to transmit heat to the outside of the tire bead, the heat dissipation performance of the tire bead is further improved, fatigue damage of the tire bead is reduced, and the service life of the tire bead is prolonged; compared with the prior art, the design is more reasonable, and the actual use requirement can be better met.

Description

Technical Field

[0001] The invention relates to the technical field of tires, and in particular to a high-durability tire. Background Art

[0002] In the bead of a pneumatic tire, the separation of the carcass turn-up end of the carcass layer is an important problem that may lead to bead failure. During high-speed driving of the tire, the bead may generate a lot of heat, and the deformation of the carcass turn-up end and other reasons can also lead to failure of the carcass turn-up end. The carcass turn-up end is a key part of the tire structure. It connects the carcass and the bead, and plays an important role in the overall strength and stability of the tire. When this part separates, it may cause the tire to leak, delaminate, bulge or even blow out during use, which seriously affects driving safety.

[0003] In order to improve the durability of the tire bead, the technicians in this field have made a lot of efforts. For example, in the prior art, the invention patent with the announcement number CN105539019B discloses a pneumatic tire and a manufacturing method thereof. The patent discloses that a rubber sheet dispersed with carbon black is arranged between the end of the tire bead and the folded part of the carcass cord layer to effectively suppress the damage of the end of the tire bead due to local strain fatigue. Although the prior art and other methods that have been used to a certain extent alleviate the problem of damage caused by strain fatigue at the end, there are still other problems. First, although the rubber sheet dispersed with carbon black can suppress local fatigue damage, there is still room for improvement in suppressing end separation and improving heat dissipation performance. Secondly, the prior art mainly focuses on improving the durability of the tire, but cannot take into account the improvement of the heat dissipation performance of the tire. Therefore, how to improve the heat dissipation performance of the tire and reduce the fatigue damage of the tire is a problem that needs to be solved urgently. Summary of the invention

[0004] Based on the above problems, the present invention provides a high-durability tire. The present invention utilizes a highly thermally conductive thermoplastic resin sheet as a covering member, which can not only increase the adhesion between the carcass turn-up end and the tire chafer end and the adjacent rubber layer to achieve the effect of inhibiting separation, but also quickly dissipate the heat accumulated at the carcass rolled-up end, thereby reducing the damage caused by heat generation at the carcass rolled-up end, thereby improving the durability and service life of the tire.

[0005] In order to solve the above technical problems, the present invention provides a high-durability tire, including a bead, wherein the bead is provided with a bead core buried in the bead, a filled bead filler is provided around the bead core, a folded and stuck carcass layer is provided on the outside of the bead filler, the folded part of the carcass layer is provided with a carcass turn-up end, a bead wrapper is provided on the outside of the carcass layer, the folded part of the bead wrapper is provided with a bead wrapper end, the carcass turn-up end and the bead wrapper end are located on the same side, the bead is also provided with a sidewall rubber layer connected to the outside of the bead, The carcass turn-up end and the chafer end are both provided with covering parts covering the corresponding carcass turn-up end and chafer end, and the outer sides of the carcass turn-up end and the chafer end are provided with rubber supporting layers, and the rubber supporting layer covers the outer sides of the covering parts. When the covering parts are prepared by using a mixing process, the following components in mass fractions are added: 10-50% of thermoplastic resin, 30-80% of rubber matrix, and 30-50% of magnesium oxide; when the rubber supporting layer is prepared by using a traditional rubber mixing process, 10%-50% of thermal conductive material is added.

[0006] Furthermore, the thermoplastic resin may be one or more of polyamide resin, polyethylene resin, and polyester resin.

[0007] Furthermore, the rubber matrix includes one or more of natural rubber, styrene-butadiene rubber, butadiene rubber, isoprene rubber, and butyl rubber.

[0008] Furthermore, the magnesium oxide is magnesium oxide particles, and the particle size of the magnesium oxide particles is 20-60 μm.

[0009] Furthermore, the covering thickness of the covering member is 0.5-5 mm.

[0010] Furthermore, the thermally conductive material is a graphene sheet or magnesium oxide.

[0011] Furthermore, the thermal diffusion coefficient of the cover in the horizontal direction or the vertical direction is 0.1-0.25 cm 2 / s.

[0012] Furthermore, the preparation method of the cover is as follows: S1: adding magnesium oxide and a compounding agent to a thermoplastic resin and a rubber matrix, mixing and adding the mixture into a twin-screw compounding extruder for melt compounding, wherein the compounding agent does not contain a vulcanizing agent, and the elastomer component is dispersed in the thermoplastic resin forming a continuous phase by compounding to obtain a blended product, and the shear rate during compounding is 2500-7500 / s; S2: Add a vulcanizing agent to the blended product during mixing to dynamically vulcanize the elastomer. The vulcanization time after adding the vulcanizing agent is 15s-5min. S3: After the mixing is completed, the mixture is extruded or calendered into a film.

[0013] Furthermore, the entire mixing time is 30s-10min.

[0014] Furthermore, in step S3, the temperature during extrusion is controlled at 180-220° C., and the pressure is controlled at 10-30 MPa.

[0015] Compared with the prior art, the present invention has the following beneficial effects: the present invention uses a highly thermally conductive thermoplastic resin sheet as a cover for the carcass turn-up end and the chafer end, which can increase the adhesion between the carcass turn-up end and the chafer end and the adjacent rubber layer, inhibit separation, and improve the durability and service life of the tire, and can quickly dissipate the heat accumulated at the carcass roll-up end, reducing the damage caused by heat generation at the carcass roll-up end; the thermal diffusion coefficient of the cover in the horizontal or vertical direction of the present invention can reach 0.1-0.25cm 2 / s; The rubber support layer arranged near the end of the tire body turnup and the end of the tire chafer has high thermal conductivity. The high thermal conductivity rubber support layer can further cooperate with the covering part to transfer heat to the outside of the tire bead, further improve the heat dissipation performance of the tire bead, reduce fatigue damage of the tire bead, and increase the service life of the tire bead. Compared with the prior art, the design of the present invention is more reasonable and can better meet the needs of actual use. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a cross-sectional view of a bead of the tire of the present invention.

[0017] Among them: 1. Bead; 2. Sidewall rubber layer; 3. Carcass layer; 4. Bead core; 5. Bead filler; 6. Carcass turn-up end; 7. Bead chafer; 8. Cover; 9. Rubber support layer; 10. Bead chafer end. DETAILED DESCRIPTION

[0018] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with embodiments and drawings. The exemplary embodiments of the present invention and their description are only used to explain the present invention and are not intended to limit the present invention.

[0019] See attached Figure 1The tire of this embodiment includes a bead 1, which is provided with a bead core 4 buried in the bead 1, a filled bead filler 5 is provided around the bead core 4, a folded and stuck carcass layer 3 is provided on the outside of the bead filler 5, a carcass turn-up end 6 is provided on the folded portion of the carcass layer 3, a bead wrapper 7 is provided on the outside of the carcass layer 3, a bead wrapper end 10 is provided on the folded portion of the bead wrapper 7, the carcass turn-up end 6 and the bead wrapper end 10 are located on the same side, and the bead 1 is also provided with a sidewall rubber layer 2 connected to the outside of the bead 1.

[0020] The carcass turn-up end 6 and the chafer end 10 are both provided with a cover 8 covering the corresponding carcass turn-up end 6 and the chafer end 10, and the cover 8 can prevent the carcass turn-up end 6 and the chafer end 10 from being separated. The outer side of the carcass turn-up end 6 and the chafer end 10 is provided with a rubber support layer 9, and the rubber support layer 9 covers the outer side of the cover 8.

[0021] The bonding method and filling method between the various components of the tire bead 1 mentioned above in this embodiment are the same as those in the prior art.

[0022] The cover 8 of this embodiment is a high thermal conductivity thermoplastic resin sheet, which contains 10% to 50% by weight of thermoplastic resin, 30-80% by weight of rubber matrix, 30% to 50% of magnesium oxide, and the particle size of magnesium oxide particles is 20-60μm. The thickness of the high thermal conductivity thermoplastic resin sheet as the cover 8 of the tire body turn-up end 6 and the tire chafer end 10 can be 0.5mm-5mm. The above composition of the cover 8 can increase the adhesion of the tire body turn-up end 6 and the tire chafer end 10 to other rubber matrices and reduce separation, and on the other hand, it has high thermal conductivity, which can increase local heat dissipation and reduce fatigue damage.

[0023] In order to further transfer heat to the outside of the tire bead 1, the present embodiment is designed with a rubber support layer 9, which covers the tire body turn-up end 6 and the tire chafer end 10 covered with the cover 8. Since 10%-50% of a thermally conductive substance (the thermally conductive substance may be a graphene sheet or magnesium oxide) is added to the rubber support layer 9 of the present invention, the tire bead 1 can further cooperate with the thermoplastic resin sheet (cover 8) to transfer heat to the outside of the tire bead 1 without affecting its function, thereby further reducing fatigue damage of the tire bead 1.

[0024] The rubber matrix in this embodiment includes one or more of natural rubber, styrene-butadiene rubber (SBR), butadiene rubber (BR), isoprene rubber (IR), butyl rubber (IIR), etc. The raw rubber may be appropriately mixed with a vulcanizing agent, a vulcanization accelerator, a plasticizer, an antioxidant, etc. The thermoplastic resin in this embodiment may be one or more of a polyamide resin, a polyethylene resin, and a polyester resin.

[0025] The preparation method of the thermoplastic resin sheet of this embodiment is as follows: S1: adding magnesium oxide and a compounding agent to a thermoplastic resin and a rubber matrix, mixing and adding the mixture to a twin-screw compounding extruder for melt compounding, wherein the compounding agent does not contain a vulcanizing agent, and the compounding agent may contain a plasticizer, an antioxidant, a filler, etc. commonly added in the prior art, and the elastomer component is dispersed in the thermoplastic resin forming a continuous phase by compounding to obtain a blended product, and the shear rate during compounding is 2500-7500 / s; S2: Add a vulcanizing agent to the blended product during mixing to dynamically vulcanize the elastomer; the vulcanization time after adding the vulcanizing agent is 15s-5min, and the entire mixing time is 30s-10min; S3: After the mixing is completed, the film is formed by extrusion or calendaring. The temperature of the extruder in this embodiment is controlled at 180-220° C. and the pressure is controlled at 10-30 MPa.

[0026] Except for the parameters and ingredients specified in this embodiment, the other preparation processes of the above preparation method are the same as those in the prior art and will not be described in detail in this embodiment.

[0027] The thermal diffusion coefficient of the cover 8 prepared in this embodiment in the horizontal direction or the vertical direction is 0.1-0.25cm 2 / s.

[0028] The rubber support layer 9 of this embodiment can be prepared by a conventional rubber mixing process. The difference is that the rubber support layer 9 uses high thermal conductivity materials such as graphene and magnesium oxide to replace part of the carbon black, and the content of the high thermal conductivity material is 10%-50%.

[0029] This embodiment tests the performance of a tire equipped with the bead 1 of this embodiment. The tire used for the test has a size of 205 / 60R16 and is mounted on a rim having a rim size specified by JATMA.

[0030] This embodiment conducted five groups of experiments, among which Experiment 1 was Figure 1 The pneumatic tire shown has a thermoplastic resin sheet containing 0% by weight of magnesium oxide, and the thickness of the thermoplastic resin sheet (covering member 8) is 2.5 mm. Figure 1The pneumatic tire shown has a thermoplastic resin sheet containing 30% by weight of magnesium oxide, and the thickness of the thermoplastic resin sheet is 2.5 mm. Figure 1 The pneumatic tire shown has a thermoplastic resin sheet containing 30% by weight of magnesium oxide, and the thickness of the thermoplastic resin sheet is 2.5 mm. The difference between Experiment 3 and Experiment 2 is that the rubber supporting layer 9 of Experiment 3 contains 20% by weight of magnesium oxide.

[0031] Comparative Example 1 is Figure 1 The pneumatic tire shown in FIG. 1 has a rubber sheet as a cover 8 of the carcass turn-up end 6, and the thickness of the rubber sheet is 2.5 mm. Figure 1 The tire shown does not have the carcass turn-up end 6 cover 8, but is otherwise the same as the above-mentioned embodiment.

[0032] In this embodiment, the tire is subjected to the following test to test heat dissipation: the temperature changes near the carcass turn-up end 6 and the chafer end 10 of the tire bead 1 are measured by a temperature sensor. The results are shown in Table 1, where the larger the value, the higher the heat accumulated in the area.

[0033] Test tire bead 1 fatigue durability: After 14 days of thermal degradation (70°C), the test tire is driven on a drum while spraying ozone (air pressure: 180 kPa, load: 88% of the standard load) until fatigue damage occurs on bead 1, including separation of the carcass turnup end 6 or the bead chafer end 10 or a large crack with a depth of 1 or more appears on bead 1. The running distance and crack state are indexed, and the larger the number, the better the groove crack resistance.

[0034] Table 1 Effect verification

[0035] As can be seen from Table 1, the high thermal conductivity thermoplastic resin sheet can improve the heat dissipation and durability of the tire bead 1, because the high thermal conductivity plastic sheet has good viscosity and can well prevent the end of the tire from separating. At the same time, since the sheet has high thermal conductivity, it can effectively reduce the heat accumulation of the tire, thereby reducing the fatigue damage of the tire. In addition, the nearby rubber support layer has a certain thermal conductivity, which can further improve the heat dissipation and durability of the tire.

[0036] The above is an embodiment of the present invention. The above embodiments and the specific parameters in the embodiments are only for the purpose of clearly describing the invention verification process, and are not intended to limit the patent protection scope of the present invention. The patent protection scope of the present invention is still subject to its claims. Any equivalent structural changes made by using the contents of the description and drawings of the present invention should be included in the protection scope of the present invention.

Claims

1. A high-durability tire, comprising a bead (1), wherein the bead (1) is provided with a bead core (4) buried in the bead (1), a filled bead filler (5) is provided around the bead core (4), a folded and stuck carcass layer (3) is provided on the outside of the bead filler (5), a carcass turn-up end (6) is provided on the folded-back portion of the carcass layer (3), a bead wrapper (7) is provided on the outside of the carcass layer (3), a bead wrapper end (10) is provided on the folded-back portion of the bead wrapper (7), the carcass turn-up end (6) and the bead wrapper end (10) are located on the same side, the bead (1) is further provided with a sidewall rubber layer (2) connected to the outside of the bead (1), characterized in that The carcass turn-up end (6) and the chafer end (10) are both provided with a covering member (8) covering the corresponding carcass turn-up end (6) and the chafer end (10); the outer sides of the carcass turn-up end (6) and the chafer end (10) are provided with a rubber support layer (9); the rubber support layer (9) covers the outer side of the covering member (8); when the covering member (8) is prepared using a mixing process, the following components in mass fraction are added: 10%-50% of thermoplastic resin, 30%-80% of rubber matrix, and 30%-50% of magnesium oxide; when the rubber support layer (9) is prepared using a conventional rubber mixing process, 10%-50% of a thermal conductive material is added.

2. A high-durability tire according to claim 1, characterized in that: The thermoplastic resin may be one or more of polyamide resin, polyethylene resin, and polyester resin.

3. A high-durability tire according to claim 1, characterized in that: The rubber matrix includes one or more of natural rubber, styrene-butadiene rubber, butadiene rubber, isoprene rubber, and butyl rubber.

4. A high-durability tire according to claim 1, characterized in that: The magnesium oxide is magnesium oxide particles, and the particle size of the magnesium oxide particles is 20-60 μm.

5. The high-durability tire according to claim 1, characterized in that: The covering thickness of the covering member is 0.5-5 mm.

6. The high-durability tire according to claim 1, characterized in that: The thermally conductive material is a graphene sheet or magnesium oxide.

7. The high-durability tire according to claim 1, characterized in that: The thermal diffusion coefficient of the cover in the horizontal or vertical direction is 0.1-0.25cm 2 / s.

8. The high-durability tire according to claim 1, characterized in that: The preparation method of the cover is as follows: S1: adding magnesium oxide and a compounding agent to a thermoplastic resin and a rubber matrix, mixing and adding the mixture into a twin-screw compounding extruder for melt compounding, wherein the compounding agent does not contain a vulcanizing agent, and the elastomer component is dispersed in the thermoplastic resin forming a continuous phase by compounding to obtain a blended product, and the shear rate during compounding is 2500-7500 / s; S2: Add a vulcanizing agent to the blended product during mixing to dynamically vulcanize the elastomer. The vulcanization time after adding the vulcanizing agent is 15s-5min. S3: After the mixing is completed, the mixture is extruded or calendered into a film.

9. A high-durability tire according to claim 8, characterized in that: The entire mixing time is 30s-10min.

10. The high-durability tire according to claim 8, characterized in that: In step S3, the temperature during extrusion is controlled at 180-220° C., and the pressure is controlled at 10-30 MPa.

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