Asymmetric tire tread and mouth-shaped plate for tread extrusion

Abstract

The invention relates to an asymmetric tire tread and a mouth-shaped plate for tread extrusion, and belongs to the field of tire design, the asymmetric tire tread comprises a tread bottom area, a first tire crown area and a second tire crown area which are arranged above the tread bottom area in parallel, and tire shoulder areas which are symmetrically arranged on two sides of the tread; wherein the tire tread bottom area, the first tire crown area, the second tire crown area and the tire shoulder area adopt different rubber material formulas. According to the prepared asymmetric tire, the inner side provided with multiple pattern grooves has excellent wetland drainage performance, and the outer side provided with large pattern blocks has good ground gripping control performance; the technical problem that the existing tread design cannot meet different functional requirements of inner and outer treads on the two sides of the center line of the asymmetric pattern tire tread is solved.

Description

Technical Field

[0001] The invention belongs to the technical field of tire design, and in particular relates to an asymmetric tire tread and a die plate for tread extrusion. Background Art

[0002] The outer tire is a major component of the wheel, and it consists of three major parts: the tread, the carcass, and the bead. The tread is produced by a rubber extruder extrusion process, and includes the crown, shoulder, and sidewall. The crown is the part of the tire that is in direct contact with the ground, and can withstand friction and all loads, reduce the impact on the cord layer, and protect the cord layer and the inner tube from mechanical damage. It has the functions of wear resistance and buffering; the shoulder is the transition part between the crown and the sidewall, which is used to fill the difference in curvature between the tread and the carcass. It is often made into a pattern to dissipate heat and improve grip. It has the functions of connecting the sidewall, filling the curvature, and extreme control; the bottom of the tread is used to connect the crown and the carcass, buffer the impact and vibration on the carcass, reduce the impact of the tire over bumps, and improve ride comfort.

[0003] Because the functions of different parts of the tire tread are different, the rubber performance requirements of different parts of the same tread are also different during tire design. Based on this, the current tread design generally adopts the following forms: Figure 1 As shown in FIG. 1 , the entire tread is made of one formula rubber material, that is, the crown, shoulder and bottom of the tread are made of the same rubber material after extrusion and pressing, which is convenient to manufacture and the obtained tread structure is simple. However, if the comprehensive performance requirements of the crown, shoulder and bottom of the tread are to be met at the same time, the rubber material cost will increase, and the performance of each part of the tread is not as good as that of the tire tread obtained by using multiple formula rubber materials; refer to the attached Figure 2 As shown, the tread is obtained by extruding and pressing two kinds of rubber compounds, that is, the tread bottom area 1 and the crown area 2 of the tread are made of two different rubber compounds and are pressed into two parts; refer to the attached Figure 3 As shown, the tread is obtained by extruding and pressing three kinds of rubber compounds, that is, the tread bottom area 1, the crown area 2, and the shoulder area 3 of the tread are each made of rubber compounds with different formulas and are divided into four parts for pressing, among which the two shoulders are symmetrically distributed on both sides of the crown.

[0004] However, in the above tread design, the crown part uses the same rubber formula and is a part of the tread. For asymmetric pattern tires with inconsistent or irregular patterns on the inner and outer sides of the tread centerline, the existing tread design cannot simultaneously meet the different functional requirements of the inner and outer treads of the asymmetric pattern tire. Therefore, those skilled in the art need to provide a tread structure suitable for asymmetric tires. Summary of the invention

[0005] In view of the technical problem in the related art that the tread design cannot meet the different functional requirements of the inner and outer treads on both sides of the center line of the tread of an asymmetric pattern tire, the present invention provides an asymmetric tire tread and a die plate for tread extrusion. By dividing the tire tread into multiple areas and adopting different rubber formulations, an asymmetric tire is prepared, so that the inner side with more pattern grooves has excellent wetland drainage performance, and the outer side with larger pattern blocks has good grip and control performance, thereby meeting the different functional requirements of the inner and outer treads of the asymmetric pattern tire.

[0006] The present invention provides an asymmetric tire tread, comprising a tread bottom area, a first tread crown area and a second tread crown area arranged in parallel above the tread bottom area, and shoulder areas symmetrically arranged on both sides of the tread; wherein the rubber compound formulas used in the tread bottom area, the first tread crown area, the second tread crown area, and the shoulder area are different. This technical solution can realize different functional requirements of different areas of the same tread, and can also be compatible with the functional requirements of symmetrical tire treads.

[0007] In some embodiments, the first crown region adopts the first crown rubber material, and the 15% tensile stress (M15) of the first crown rubber material is 1.1-1.2MPa, preferably in the range of 1.0-1.1MPa; the 25% tensile stress (M25) is 1.2-1.5MPa, preferably in the range of 1.3-1.4MPa; the 50% tensile stress (M50) is 1.7-2.1MPa, preferably in the range of 1.8-2.0MPa; the Akron wear is 0.15-0.20cm3 / 1.61km, preferably in the range of 0.10-0.15cm3 / 1.61km. By adopting a high grip and high wear-resistant rubber formula for the outer tread with larger pattern blocks, the grip and handling performance of the outer tread of the asymmetric tire can be achieved.

[0008] In some embodiments, the second crown region adopts the second crown rubber, and the mechanical loss value tanδ(0℃) of the second crown rubber at 0℃ is 0.3-0.5, preferably in the range of 0.4-0.5; the wet friction coefficient μp is 1.4-1.6, preferably in the range of 1.5-1.6. By adopting the anti-wet rubber formula for the inner tread with more grooves, the wet drainage performance of the inner tread of the asymmetric tire can be achieved.

[0009] In some embodiments, the third crown rubber material is used in the bottom area of ​​the tread, and the third crown rubber material glues and connects the first crown area, the second crown area and the tire cap layer component. This technical solution can buffer the impact and vibration of the tire body from the outside, reduce the impact force of the tire going over bumps, and improve ride comfort; at the same time, the first crown rubber material, the second crown rubber material and the semi-finished parts such as the tire cap layer are glued and connected.

[0010] In some embodiments, the shoulder region includes a first shoulder region located outside the first crown region and a second shoulder region located outside the second crown region, and the second shoulder region and the first shoulder region use different rubber compound formulations. The first shoulder rubber compound shows no cracking after 300,000 flexing tests according to GB / T 13934-2006 "Determination of flexing cracking and crack growth of vulcanized rubber or thermoplastic rubber (Demessia type)"; the second shoulder rubber compound shows cracking level 1 or no cracking after 300,000 flexing tests according to GB / T 13934-2006 "Determination of flexing cracking and crack growth of vulcanized rubber or thermoplastic rubber (Demessia type)". The first shoulder rubber compound and the second shoulder rubber compound can be used to adhere the semi-finished tread component and the semi-finished sidewall component, so that the two semi-finished tread and sidewall components are firmly connected to form a tight whole to achieve the strength required by the tire; by strengthening the grip of the rubber compound in the first shoulder region alone, the grip control of the tire at the extreme side slip position is achieved.

[0011] In some of the embodiments, the cross-sectional area of ​​the bottom area of ​​the tread accounts for 10% to 15% of the cross-sectional area of ​​the entire tread area; the sum of the cross-sectional areas of the first crown area and the second crown area accounts for 80% to 85% of the cross-sectional area of ​​the entire tread area; the sum of the cross-sectional areas of the two shoulder areas accounts for 3% to 7% of the cross-sectional area of ​​the entire tread area. This technical solution can achieve a reasonable proportion of asymmetric tire pattern performance, maximize the tread control and shock absorption performance, and ensure that it will not stall and roll in extreme cornering situations. Setting the cross-sectional area of ​​the second shoulder area equal to that of the first shoulder area can achieve the technical effect of extreme vehicle control and grip whether the symmetrical pattern tire is installed forward or reverse.

[0012] In some embodiments, the ratio of the cross-sectional areas of the first crown region to the second crown region is 1: 1. By adjusting the ratio of the cross-sectional areas of the first crown region to the second crown region to 3:2 or 2:3, an asymmetric tread design can be achieved.

[0013] In addition, the present invention also provides a die plate for tread extrusion, which is used to prepare the above-mentioned asymmetric tire tread. The die plate for tread extrusion includes an upper tread die plate and a lower tread die plate connected to the upper tread die plate, wherein a positioning groove is set at the middle position of the top of the upper tread die plate; chamfers are set at the edges of both ends of the upper tread die plate and the lower tread die plate; a tread die is set at the bottom of the upper tread die plate, and the bottom of the tread die is located at the center of the boundary line between the upper tread die plate and the lower tread die plate. Different rubber materials enter through the channel of the die plate for tread extrusion, and are extruded to obtain various tread components, which are combined and pressed out as an integrated tread to obtain an asymmetric tire tread. The technical solution sets a positioning groove with an arc-shaped opening in the middle of the top of the upper tread mouth plate, which can be positioned at the position of the tread extruder mouth plate, has an anti-error function, and prevents the tread mouth plate from being installed upside down; by designing chamfers on the left and right sides of the upper tread mouth plate and the lower tread mouth plate, it can prevent the tread mouth plate from being installed upside down.

[0014] In some of the embodiments, the tread mouth shape includes a first crown rubber material channel, a second crown rubber material channel, a third crown rubber material channel, a first shoulder rubber material channel and a second shoulder rubber material channel, wherein the first crown rubber material channel and the second crown rubber material channel are arranged in parallel at the upper end of the tread mouth shape, the third crown rubber material channel is arranged at the lower end of the tread mouth shape, the first shoulder rubber material channel is located outside the first crown rubber material channel, the second shoulder rubber material channel is located outside the second crown rubber material channel, and the second shoulder rubber channel is symmetrical with the first shoulder rubber channel.

[0015] In some of the embodiments, a sheet-like spacer with a gradually varying thickness is provided at the connection between the first tread crown rubber material channel and the second tread crown rubber material channel, and other channels are spaced according to the shape of the flow channel itself.

[0016] Based on the above technical solution, compared with the prior art, the beneficial effects of the present invention are:

[0017] (1) In the embodiment of the present invention, the asymmetric tire tread is composed of five tread components obtained by adopting four formulations, which can simultaneously meet the different functions of the inner and outer regions on both sides of the tread centerline in the asymmetric pattern tread design. The inner tread with more pattern grooves adopts an anti-slip rubber formulation, which improves the wetland drainage performance of the tire; the outer tread with larger pattern blocks adopts a high wear-resistant rubber formulation, which improves the grip and handling performance of the tire.

[0018] (2) In the embodiment of the present invention, the die plate for tread extrusion is provided with a positioning groove on the upper tread die plate, so that the tread die plate can be prevented from being installed upside down; chamfers are provided at the corresponding ends of the upper tread die plate and the lower tread die plate, so that the tread die plate can be prevented from being installed upside down left to right; a sheet-like spacer from thick to thin is provided at the connection between the first crown area and the second crown area, so that the two rubber materials flowing into the crown area can be separated. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of this application. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0020] Figure 1 A schematic diagram of a tread structure using a rubber compound formulation for an existing tread design;

[0021] Figure 2 A schematic diagram of the tread structure of two types of rubber compounds used in the existing tread design;

[0022] Figure 3 Schematic diagram of tread structure using three types of rubber compound formulations for existing tread designs;

[0023] Figure 4 Schematic diagram of tire tread structure using four kinds of rubber compound formulations according to the embodiment of the present invention;

[0024] Figure 5 This is a schematic structural diagram of a die plate for tread extrusion according to an embodiment of the present invention;

[0025] Figure 6 A bottom view of a die plate for tread extrusion according to an embodiment of the present invention;

[0026] Figure 7 A schematic diagram of the die structure of a tread of a die plate for tread extrusion according to an embodiment of the present invention;

[0027] In the figure:

[0028] 1. Tread bottom area; 2. Crown area, 21. First crown area, 22. Second crown area; 3. Shoulder area, 31. First shoulder area, 32. Second shoulder area; 4. Upper tread mouth plate, 41. Positioning groove, 42. Tread mouth, 421. First crown rubber channel, 422. Second crown rubber channel, 423. Third crown rubber channel, 424. First shoulder rubber channel, 425. Second shoulder rubber channel; 5. Lower tread mouth plate, 51. Chamfer. DETAILED DESCRIPTION

[0029] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0030] In the description of the present invention, it should be understood that the terms "first", "second", and "third" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, a feature defined as "first", "second", and "third" may explicitly or implicitly include one or more of the features.

[0031] The present invention provides an asymmetric tire tread and a die plate for tread extrusion, which can be applied to the design of asymmetric pattern treads and simultaneously satisfy the different functions of the inner and outer regions on both sides of the tread centerline in the asymmetric pattern tread design. The inner tread with more pattern grooves adopts an anti-slip rubber formula, thereby improving the wetland drainage performance of the tire; the outer tread with larger pattern blocks adopts a high-wear-resistant rubber formula, thereby improving the grip and handling performance of the tire.

[0032] Reference Figure 4 As shown, in an exemplary embodiment of the asymmetric tire tread of the present invention, the asymmetric tire tread includes a tread bottom area 1 located at the bottom of the tread, a first crown area 21 and a second crown area 22 arranged in parallel above the tread bottom area 1, and shoulder areas 3 symmetrically arranged on both sides of the tread; wherein the rubber formulations used in the tread bottom area 1, the first crown area 21, the second crown area 22, and the shoulder area 3 are different.

[0033] In a preferred embodiment, the asymmetric tire tread of the present invention uses four different types of rubber compounds, including a first crown rubber compound, a second crown rubber compound, a third crown rubber compound and a first shoulder rubber compound, wherein the first crown region 21 is used as the outer side of the tire tread, has a large tread pattern block, and assumes the function of gripping and controlling. The first crown region 21 uses a first crown rubber compound with a high wear-resistant type formulation, and the 15% modulus (M15) of the first crown rubber compound is 1.1-1.2 MPa, preferably The preferred range is 1.0-1.1MPa; the 25% modulus (M25) is 1.2-1.5MPa, preferably 1.3-1.4MPa; the 50% modulus (M50) is 1.7-2.1MPa, preferably 1.8-2.0MPa; the Akron wear is 0.15-0.20cm3 / 1.61km, preferably 0.10-0.15cm3 / 1.61km. The second crown area 22 is the inner side of the tire tread, with many grooves and a drainage function. The second crown area 22 uses a second crown rubber compound with an excellent anti-slip formula. The mechanical loss value of the second crown rubber compound at 0°C, tanδ(0°C), is 0.3-0.5, preferably 0.4-0.5; the wet friction coefficient μp is 1.4-1.6, preferably 1.5-1.6. By using an anti-slip rubber compound formula for the inner tread with more grooves, the wetland drainage performance of the inner tread of the asymmetric tire can be achieved. The bottom area 1 of the tread uses a third crown rubber compound with a cushioning comfort type formula. The third crown rubber compound connects the first crown area 21, the second crown area 22 and the semi-finished parts such as the tire cap layer, which can buffer the impact and vibration of the tire body, reduce the impact force of the tire over the bump, and improve the ride comfort; the shoulder areas 3 on both sides use the first shoulder rubber compound of the same formula. Preferably, the first shoulder rubber compound uses the same or similar type of rubber compound formula as the semi-finished parts of the sidewall. The first shoulder rubber compound has no cracks after 300,000 flexion tests in accordance with GB / T 13934-2006 "Determination of flex cracking and crack growth of vulcanized rubber or thermoplastic rubber (Demecia type)". It has the following advantages: it is easy to stick the semi-finished tread components and the semi-finished sidewall components, so that the two semi-finished components of the tread and sidewall are firmly connected. No matter it is the side-crown type or the crown-side type, the sidewall can tightly wrap the tread or the tread can tightly wrap the sidewall to form a tight whole to achieve the strength required by the tire; rounded transition between the tread and the sidewall semi-finished components. Since the tread has a small curvature and the carcass cord layer has a large curvature, the lower part of both sides of the tread semi-finished components must be filled with rubber during molding to make the tire edges and corners rounded, thereby forming a shoulder here; extreme control.

[0034] In a preferred embodiment, the tread of the asymmetric tire of the present invention adopts five different types of rubber compounds, including a first crown rubber compound, a second crown rubber compound, a third crown rubber compound, a first shoulder rubber compound and a second shoulder rubber compound, wherein the first crown region 21 adopts a first crown rubber compound with a high wear-resistant formula, and the 15% tensile stress (M15) of the first crown rubber compound is 1.1 to 1.2 MPa, preferably in the range of 1.0 to 1.1 MPa; the 25% tensile stress (M25) is 1.2 to 1.5 MPa, preferably in the range of 1.3 to 1.4 MPa; the 50% tensile stress (M50) is 1.7 to 2.1 MPa, preferably in the range of 1.8 to 2.0 MPa; the Akron wear is 0.15 to 0.20 cm3 / 1.61 km, preferably in the range of 0.10 to 0.15 cm3 / 1.61 km. The second crown area 22 adopts a second crown rubber material with an excellent anti-slip formula, and the second crown rubber material has a 0°C mechanical loss value tanδ(0°C) of 0.3-0.5, preferably in the range of 0.4-0.5; the wet friction coefficient μp is 1.4-1.6, preferably in the range of 1.5-1.6. To compensate for the noise problem caused by the excessively large tread blocks in the first crown area 21, the second crown rubber material used in the second crown area 22 can be further increased by 5-7 portions of anti-skid resin on the premise of excellent anti-skid performance, thereby reducing the rubber modulus at room temperature and making the rubber softer, thereby increasing comfort; the tread bottom area 1 adopts a third crown rubber material with a cushioning comfort type formula, and the first crown area 21, the second crown area 22 and semi-finished components such as the tire cap layer are glued and connected, which can buffer the impact and vibration of the tire body, reduce the impact force of the tire over bumps, and improve ride comfort; the shoulder area 3 includes a first shoulder area 31 located outside the first crown area 21, and a second shoulder area 32 located outside the second crown area 22, and the second shoulder area 32 and the first shoulder area 31 use different rubber formulas; the first shoulder area 31 uses the first shoulder rubber material, and the first shoulder rubber material is GB / T The second shoulder area 32 adopts the second shoulder rubber compound, and the second shoulder rubber compound is tested according to GB / T 13934-2006 "Determination of flex cracking and crack growth of vulcanized rubber or thermoplastic rubber (Demethea type)" for 300,000 times of flexion test and shows crack level 1 or no crack after 300,000 times of flexion test.

[0035] In the asymmetric tire tread of the present invention, the cross-sectional area of ​​the bottom region 1 of the tread accounts for 10% to 15% of the cross-sectional area of ​​the entire tread region; the first crown region 21 is located at the top of the tread, the first crown region 21 is arranged on the bottom region 1 of the tread, and the bottom end of the first crown region 21 is in contact with the top end of the bottom region 1 of the tread; the second crown region 22 is located at the top of the tread, the second crown region 22 is arranged on the bottom region 1 of the tread, and the bottom end of the second crown region 22 is in contact with the top end of the bottom region 1 of the tread, the inner side of the second crown region 22 is in contact with the inner side of the first crown region 21, the second crown region 22 and the first crown region 21 are arranged side by side on the bottom region 1 of the tread, the total cross-sectional area of ​​the second crown region 22 and the first crown region 21 accounts for 80% to 85% of the cross-sectional area of ​​the entire tread region, and the cross-sectional area ratio of the first crown region 21 to the second crown region 22 is 1:1 or 3:2 or 2:3. The first shoulder area 31 is located on one side of the tread, and the first shoulder area 31 is in contact with the first crown area 21; the second shoulder area 32 is located on the other side of the tread, and the second shoulder area 32 is in contact with the second crown area 22. The second shoulder area 32 and the first shoulder area 31 are symmetrically arranged on both sides of the tread, and the cross-sectional area of ​​the second shoulder area 32 is equal to that of the first shoulder area 31, and the total cross-sectional area of ​​the second shoulder area 32 and the first shoulder area 31 accounts for 3% to 7% of the cross-sectional area of ​​the entire tread area.

[0036] The present invention also provides a die plate for tread extrusion, which is used to prepare the above-mentioned asymmetric tire tread. Figure 5 As shown, the die plate for tread extrusion comprises an upper tread die plate 4 and a lower tread die plate 5 connected to the upper tread die plate 4; a positioning groove 41 is arranged at the middle position of the upper end of the upper tread die plate 4, and the positioning groove 41 is an arc-shaped opening structure, which can be positioned at the position of the tread extruder die plate, and has an error-proofing function to prevent the tread die plate from being installed upside down; a tread die 42 is arranged at the middle position of the bottom of the upper tread die plate 4, and the bottom of the tread die 42 is located at the center position of the boundary line between the upper tread die plate 4 and the lower tread die plate 5; refer to the attached Figure 6 As shown, the edges of the upper tread die plate 4 and the lower tread die plate 5 are chamfered at both ends, which has an anti-error function and can prevent the tread die plate from being installed upside down. Rubber materials of various formulations enter through the channel of the tread extrusion die plate, and are extruded to obtain various tread components, which are combined and pressed out as an integrated tread to obtain an asymmetric tire tread. In a preferred embodiment, the two sides of the lower tread die plate 5 are fixedly connected to the upper tread die plate 4 by bolts.

[0037] Reference Figure 7As shown, the tread mouth shape of the present invention includes a first crown rubber material channel 421, a second crown rubber material channel 422, a third crown rubber material channel 423, a first shoulder rubber material channel 424, and a second shoulder rubber material channel 425. The first crown rubber material channel 421 and the second crown rubber material channel 422 are arranged in parallel at the upper end of the tread mouth shape, and a sheet-like interval with a gradually changing thickness is arranged at the connection between the first crown rubber material channel 421 and the second crown rubber material channel 422, and the third crown rubber material channel 423 is arranged at the lower end of the tread mouth shape; the first shoulder rubber material channel 424 is arranged outside the first crown rubber material channel 421, and the second shoulder rubber material channel 425 is located outside the second crown rubber material channel 422, and the second shoulder rubber material channel 425 is symmetrically arranged with the first shoulder rubber material channel 424. The tread extruder extrude five kinds of tread rubber materials, which flow through the tread pre-die and then enter the die plate for tread extrusion, wherein the first crown rubber material channel 421 flows through the first crown rubber material, the second crown rubber material channel 422 flows through the second crown rubber material, the third crown rubber material channel 423 flows through the third crown rubber material, the first shoulder rubber material channel 424 flows through the first shoulder rubber material, and the second shoulder rubber material channel 425 flows through the second shoulder rubber material. In a preferred embodiment, four kinds of rubber materials with different formulas enter through the five channels of the die plate for tread extrusion, and are extruded to obtain five tread components, which are combined and extruded into an integrated tread to obtain an asymmetric tire tread. In a preferred embodiment, five kinds of rubber materials with different formulas enter through the five channels of the die plate for tread extrusion, and are extruded to obtain five tread components, which are combined and extruded into an integrated tread to obtain an asymmetric tire tread.

[0038] The following is combined with Figures 5 to 7 The specific structure and working process of the specific embodiment of the asymmetric tire tread and the die plate for tread extrusion of the present invention are described as follows:

[0039] Example 1

[0040] Reference Figure 5 As shown, the tread of the asymmetric tire of this embodiment adopts four different formula rubber materials, namely, the first crown rubber material, the second crown rubber material, the third crown rubber material and the first shoulder rubber material, which enter from the five channels of the tread extrusion die plate, and are extruded to obtain five tread components, which are combined and pressed out as an integrated tread, wherein the first crown rubber material has a 15% tensile stress (M15) of 1.1 MPa, a 25% tensile stress (M25) of 1.4 MPa, a 50% tensile stress (M50) of 2.0 MPa, and an Akron wear of 0.20 cm3 / 1.61 km; the second crown rubber material has a 0°C mechanical loss value tanδ(0°C) of 0.5, and a wet friction coefficient μp of 1.6; the third crown rubber material adopts a conventional tread formula; the first shoulder rubber material has a GB / T 13934-2006 "Determination of flex cracking and crack growth of vulcanized rubber or thermoplastic rubber (Demethea type)" No cracking was observed after 300,000 flexion tests.

[0041] The specific working process is as follows: the tread extruder extrude four kinds of tread rubber materials, namely the first crown rubber material, the second crown rubber material, the third crown rubber material and the first shoulder rubber material, which flow through the tread pre-mouth and then enter the Figure 7 The five rubber channels of the die plate for tread extrusion are shown, wherein the first crown rubber flows through the first crown rubber channel 421, the second crown rubber flows through the second crown rubber channel 422, the third crown rubber flows through the third crown rubber channel 423, and the first shoulder rubber is divided into two, flowing through the first shoulder rubber channel 424 and the second shoulder rubber channel 425 respectively; after each rubber fills the corresponding tread area, the intervals between each channel will gradually disappear, and each rubber is gathered and merged into an integrated tread, and finally flows out from the front side of the die plate for tread extrusion.

[0042] Example 2

[0043] Reference Figure 5 As shown, the tread of the asymmetric tire of this embodiment uses five different formula rubber materials, namely the first crown rubber material, the second crown rubber material, the third crown rubber material, the first shoulder rubber material, and the second shoulder rubber material, which enter from the five channels of the tread extrusion die plate, are extruded to obtain five tread components, which are combined and pressed out as an integrated tread, wherein the 15% tensile stress (M15) of the first crown rubber material is 1.1 MPa, the 25% tensile stress (M25) is 1.4 MPa, the 50% tensile stress (M50) is 2.0 MPa, and the Akron wear is 0.20 cm

[0044] / 1.61km; the second crown rubber compound has a mechanical loss value of tanδ(0℃) of 0.5 and a wet friction coefficient μp of 1.6; the third crown rubber compound adopts a conventional tread formulation; the first shoulder rubber compound and the second shoulder rubber compound meet the requirements of GB / T 13934-2006 "Determination of flexural cracking and crack growth of vulcanized rubber or thermoplastic rubber (Demethia type)" and show no cracks after 300,000 flexion tests.

[0045] The specific working process is as follows: the tread extruder extrude five kinds of tread rubber materials, namely the first crown rubber material, the second crown rubber material, the third crown rubber material, the first shoulder rubber material and the second shoulder rubber material, which flow through the tread pre-mouth and then enter the Figure 7 The tread extrusion die plate shown has five rubber channels, wherein the first crown rubber flows through the first crown rubber channel 421, the second crown rubber flows through the second crown rubber channel 422, the third crown rubber flows through the third crown rubber channel 423, the first shoulder rubber flows through the first shoulder rubber channel 424, and the second shoulder rubber flows through the second shoulder rubber channel 425; after each rubber fills the corresponding tread area, the intervals between each channel will gradually disappear, and each rubber is gathered and merged into an integrated tread, and finally flows out from the front side of the tread extrusion die plate.

[0046] Performance Test:

[0047] The tire treads prepared in Example 1 and Example 2 were respectively subjected to actual vehicle tests. Compared with conventional tires, the handling performance was greatly improved, the wet handling was much better than before, and the extreme obstacle avoidance capability was greatly improved.

[0048] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, ordinary technicians in the field should understand that the specific implementation methods of the present invention can still be modified or some technical features can be replaced by equivalents without departing from the spirit of the technical solution of the present invention, which should be included in the scope of the technical solution for protection of the present invention.

Claims

1. An asymmetric tire tread, characterized in that: It includes a tread bottom area, a first crown area and a second crown area arranged side by side above the tread bottom area, and shoulder areas symmetrically arranged on both sides of the tread; wherein the rubber formulas used in the tread bottom area, the first crown area, the second crown area, and the shoulder areas are different.

2. The asymmetric tire tread according to claim 1, characterized in that: The first crown area adopts the first crown rubber material, the 15% tensile stress of the first crown rubber material is 1.1-1.2MPa, the 25% tensile stress is 1.2-1.5MPa, the 50% tensile stress is 1.7-2.1MPa, and the Akron wear is 0.15-0.20cm 3 / 1.61km.

3. The asymmetric tire tread according to claim 1, characterized in that: The second crown area adopts the second crown rubber material, the 0°C mechanical loss value tanδ(0°C) of the second crown rubber material is 0.3-0.5, and the wet friction coefficient μp is 1.4-1.

6.

4. The asymmetric tire tread according to claim 1, characterized in that: The third tread crown rubber material is used in the bottom area of ​​the tread, and the first tread crown area, the second tread crown area and the tire cap layer component are bonded and connected by the third tread crown rubber material.

5. The asymmetric tire tread according to claim 1, characterized in that: The shoulder area includes a first shoulder area located outside the first crown area and a second shoulder area located outside the second crown area, and the second shoulder area and the first shoulder area use different rubber compound formulations.

6. The asymmetric tire tread according to claim 1, characterized in that: The cross-sectional area of ​​the bottom area of ​​the tread accounts for 10% to 15% of the cross-sectional area of ​​the entire tread area; the sum of the cross-sectional areas of the first crown area and the second crown area accounts for 80% to 85% of the cross-sectional area of ​​the entire tread area; the sum of the cross-sectional areas of the two shoulder areas accounts for 3% to 7% of the cross-sectional area of ​​the entire tread area.

7. The asymmetric tire tread according to claim 1, characterized in that: The cross-sectional area ratio of the first crown region to the second crown region is 1:1 or 3:2 or 2:

3.

8. A die plate for tread extrusion, used for preparing the asymmetric tire tread according to any one of claims 1 to 7, characterized in that: The die plate for tread extrusion includes an upper tread die plate and a lower tread die plate connected to the upper tread die plate, wherein a positioning groove is arranged at the middle position of the top of the upper tread die plate; chamfers are arranged at the two end edges of the upper tread die plate and the lower tread die plate respectively; a tread die is arranged at the bottom of the upper tread die plate, and the bottom of the tread die is located at the center position of the boundary line between the upper tread die plate and the lower tread die plate.

9. The die plate for tread extrusion according to claim 8, characterized in that: The tread mouth shape includes a first crown rubber material channel, a second crown rubber material channel, a third crown rubber material channel, a first shoulder rubber material channel and a second shoulder rubber material channel, wherein the first crown rubber material channel and the second crown rubber material channel are arranged in parallel at the upper end of the tread mouth shape, the third crown rubber material channel is arranged at the lower end of the tread mouth shape, the first shoulder rubber material channel is located outside the first crown rubber material channel, the second shoulder rubber material channel is located outside the second crown rubber material channel, and the second shoulder rubber material channel is symmetrical with the first shoulder rubber material channel.

10. The die plate for tread extrusion according to claim 9, characterized in that: A sheet-like spacer with a gradually changing thickness is arranged at the connection between the first tread crown rubber material channel and the second tread crown rubber material channel.

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