Four-season tire tread structure suitable for running on snowfield

Abstract

The invention provides a four-season tire tread structure suitable for snowfield driving, which comprises a tread body, the tread body comprises a middle pattern unit and a shoulder pattern unit, the middle pattern unit comprises a middle pattern block and side pattern blocks, the side pattern blocks are distributed on two sides of the middle pattern block, the middle pattern block comprises a plurality of groups of transverse grooves, and the shoulder pattern unit comprises a plurality of shoulder pattern units. Each group of transverse grooves is of a grenade type structure and is correspondingly and reversely arranged, the side pattern blocks comprise a plurality of groups of first pattern blocks, the first pattern blocks are of F-shaped structures, first pattern grooves of a multi-layer step structure are formed between the adjacent first pattern blocks, first longitudinal grooves are formed between the middle pattern blocks and the side pattern blocks, and second longitudinal grooves are formed between the middle pattern blocks and the side pattern blocks. The snow claws are arranged in the longitudinal grooves I in a staggered manner, and are connected with the middle pattern blocks or the side pattern blocks, so that the traction performance, the wear resistance and the dry and wet land gripping performance of a snowfield can be effectively enhanced, the driving risk is reduced, the safety is high, meanwhile, the noise can be reduced, and the service life of the tire is further prolonged.

Description

Technical Field

[0001] The present invention relates to the technical field of tires, and particularly to a four-season tire tread structure adapted for driving on snow. Background Art

[0002] Under the background of the current global climate change and the increasingly diverse transportation demands, in North America, especially in its northeastern and northern regions, due to the severe cold and frequent snowfall in winter, more stringent and special requirements are put forward for the performance of tire products. In order to fully ensure the driving safety and stability of vehicles under extremely harsh weather conditions, there is an urgent need to develop a tire product that combines multiple excellent performances - a four-season tire with 3PMSF (Three Peak Mountain Snowflake) certification.

[0003] As an internationally recognized performance standard for winter tires, the 3PMSF certification represents that the tire has excellent traction and handling performance under extreme road conditions such as snow and ice. Tires that obtain this certification must pass a series of strict and comprehensive tests, and the ASTM F1805-20 snow traction test is a crucial one. The ASTM F1805-20 standard details the test methods, procedures, and evaluation indicators, aiming to simulate the real snow environment and accurately evaluate the tire's grip, braking performance, and handling stability on snow. Only tires that successfully pass this test can be awarded the 3PMSF certification, thus providing reliable safety guarantees for consumers during winter travel.

[0004] Existing four-season tire products cannot meet the usage requirements in regions with severe cold and frequent snowfall such as North America. Their snow traction performance, wear resistance, and dry and wet grip performance are poor, resulting in insufficient tire grip, difficult starting and braking, increased driving risks, poor safety, and at the same time, the tire makes relatively large noises during driving, which not only affects the driver's attention, reduces the driver's ability to judge the road conditions, but also reduces the riding comfort, accelerates the tire aging, and further reduces the tire's performance and service life. Summary of the Invention

[0005] The purpose of the present invention is to solve the above technical deficiencies and provide a four-season tire tread structure adapted for driving on snow.

[0006] To this end, the present invention provides a four-season tire tread structure adapted for driving on snow, including a tread body. The tread body includes a central tread unit and shoulder tread units. The shoulder tread units are arranged on both sides of the central tread unit. The central tread unit includes a middle tread block and side tread blocks. The side tread blocks are distributed on both sides of the middle tread block. The middle tread block includes multiple groups of transverse grooves. Each group of transverse grooves has a grenade-like structure and is arranged in opposite directions. The side tread blocks include multiple groups of tread blocks one. The tread blocks one adopt an F-shaped structure. A tread groove one with a multi-layer stepped structure is arranged between adjacent tread blocks one. A longitudinal groove one is arranged between the middle tread block and the side tread blocks. Snow claws arranged in a staggered manner are arranged in the longitudinal groove one. The snow claws are connected to the middle tread block or the side tread blocks.

[0007] Preferably, a wedge-shaped inclined surface structure arranged in the opposite direction is provided at the side part of the middle tread block. The depth of the inclined surface structure gradually changes from 0 mm to 1 / 2 of the depth of the longitudinal groove one.

[0008] Preferably, a plurality of zigzag steel sheets are embedded in both the central tread unit and the shoulder tread units.

[0009] Preferably, the transverse grooves gradually change from thick to thin, with a gradual change depth of 2 - 3 mm. Steel sheets with a depth of 2 - 3 mm are embedded in the transverse grooves. The groove wall angle of the transverse grooves is 3 - 8°. The bottom of the transverse grooves is provided with an arc chamfer of R0.5 mm - R2.5 mm.

[0010] Preferably, the F-shaped structure includes a transverse groove three, a transverse groove four, and a longitudinal groove two. The longitudinal groove two intersects with the transverse groove three and is embedded in the transverse groove three, with an embedding depth of 2.8 - 3.5 mm. The depth and width of the longitudinal groove two both gradually change from large to small. The transverse groove four is located in the middle position of the longitudinal groove two and is embedded in the longitudinal groove two. The depth of the transverse groove four is in a gradual change form. The deepest part of the transverse groove four is 1.0 - 1.5 mm shallower than the deepest part of the transverse groove three.

[0011] Preferably, the tread groove one is zigzag, and a step one is arranged therein. The step one is formed by extending upward 3.5 - 4.5 mm along the bottom of the tread groove one. Step two and step three with a height of 1.5 - 2.5 mm are respectively arranged at both ends of the tread groove one. The step one, the step two, and the step three are in a stepped shape.

[0012] Preferably, the width of the tread groove one near the middle tread block is greater than its width near the shoulder tread unit.

[0013] Preferably, the snow claws are triangular, the radian of the bottom of the snow claws is smaller than that of the top, the width of the snow claws extends to 1 / 2 of the transverse width of the longitudinal groove, and the height of the root of the snow claws is greater than the height of the snow claws extending outward to the longitudinal groove.

[0014] Preferably, the shoulder tread pattern unit includes a transverse groove five and a transverse groove six. The transverse groove five does not extend to the shoulder tread cut-off position, and the transverse groove six extends to the shoulder tread cut-off position. Both the transverse groove five and the transverse groove six are zigzag-shaped and transition from a semi-closed state at the front end to a full groove depth state.

[0015] Preferably, the zigzag angle of the steel sheet is 45°.

[0016] The beneficial effects of the present invention are as follows: The present invention provides a four-season tire tread structure suitable for driving on snow, and has the following beneficial effects.

[0017] ⑴ For the tread structure of this tire, the contact surface width and contact area are increased, the edge effect of the shoulder tread pattern unit of the tire is increased, and at the same time, the number of tread blocks within the effective contact area is increased, improving the snow traction performance, as well as the dry grip and handling performance.

[0018] ⑵ The tire of the present application adopts a symmetrical tread pattern structure, which can well meet the wear resistance performance of the tire, solve the demand for high wear resistance and high mileage of four-season products in snowfall areas in winter, and cleverly uses the bionic "snow claw" design and "F" type design to improve the snow removal performance of the tire. At the same time, the design with multiple changes in the transverse grooves can more effectively help remove snow.

[0019] ⑶ The design of high-density and various types of zigzag 3D steel sheets can increase the rigidity of the product while reducing the strain and stress generated by the tire during intense driving, improving the snow traction performance of the tire, and more smoothly passing the ASTM F1805 snow traction test.

[0020] ⑷ The internal stepped design of the pattern groove two greatly improves the rigidity of the tread block. Combined with the tangent design of the contour shoulder, it effectively guarantees the steering stability of the tire and reduces noise. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 is a schematic structural diagram of the four-season tire tread structure in this embodiment;

[0022] Figure 2 is a schematic structural diagram of the four-season tire in this embodiment;

[0023] Figure 3 is a schematic structural diagram of the middle tread block and the side tread block in this embodiment;

[0024] Figure 4 is a schematic structural view of the right tread block and the shoulder tread unit in this embodiment;

[0025] Figure 5 is a three-dimensional structural view of the tread structure of an all-season tire in this embodiment;

[0026] Figure 6 is a schematic structural view of the transverse groove in this embodiment;

[0027] Figure 7 is a schematic structural view of the F-shaped structure in this embodiment;

[0028] Figure 8 is a schematic structural view of the snow claw in this embodiment;

[0029] Figure 9 is a dimensional drawing of the snow claw in this embodiment;

[0030] Figure 10 is a schematic structural view of the steel sheet in this embodiment;

[0031] Figure 11 is a sectional view marking diagram of the tread structure of an all-season tire in this embodiment;

[0032] Figure 12 is Figure 11 a cross-sectional view of the transverse grooves e-e, f-f, g-g' in

[0033] Figure 13 is Figure 11 a cross-sectional view of the F-shaped structures m-m, n-n', o-o', p-p' and q-q in

[0034] Figure 14 is Figure 11 a cross-sectional view of the tread grooves one h-h', i-i, j-j and k-k in

[0035] Figure 15 is Figure 11 a cross-sectional view of the transverse grooves five v-v', t-t and s-s' in

[0036] Figure 16 is Figure 11 a cross-sectional view of the transverse groove six u-u' in

[0037] Figure 17 is Figure 11 a cross-sectional view of the snow claws z-z, z-z' in

[0038] Figure 18 is Figure 11 a cross-sectional view of the triangular section E' in

[0039] Figure 19 is a tire contour diagram in this embodiment;

[0040] Figure 20 It is the imprint diagram of the tread of the all-season tire in this embodiment.

[0041] Markings in the figure: 1. Tread body; 11. Central tread unit; 111. Intermediate tread block; 112. Side tread block; 12. Shoulder tread unit; 121. Transverse groove five; 122. Transverse groove six; 2. Transverse groove; 21. Transverse groove one; 22. Transverse groove two; 3. F-shaped structure; 31. Transverse groove three; 32. Transverse groove four; 33. Longitudinal groove two; 4. Pattern groove one; 41. Step one; 42. Step two; 43. Step three; 5. Longitudinal groove one; 51. Left groove; 52. Right groove; 6. Snow claw; 7. Inclined plane structure; 8. Steel sheet; 9. Shoulder tread cut-off position; 10. Left tread block; 13. Right tread block; 14. Longitudinal groove three; 15. Longitudinal groove four; 16. Small groove; 17. Triangular section; 18. Tread block one. Detailed implementation mode

[0042] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments to help understand the content of the present invention. The methods used in the present invention are all conventional methods unless otherwise specified; the raw materials and devices used are all conventional commercially available products unless otherwise specified.

[0043] Before introducing this application in detail, Figures 12 - 16 the meaning of FD in

[0044] is explained. FD represents the full depth of the groove.

[0045] As Figures 1 - 20 shown, the present invention provides a tread structure of an all-season tire adapted for snow driving, including a tread body 1. The tread body 1 includes a central tread unit 11 and a shoulder tread unit 12. The shoulder tread unit 12 is arranged on both sides of the central tread unit 11 and is arranged in reverse symmetry.

[0046] As Figure 2 、 Figure 3 and Figure 6 shown, the central tread unit 11 includes an intermediate tread block 111 and two side tread blocks 112. The side tread blocks 112 are distributed on both sides of the intermediate tread block 111, that is, the intermediate tread block 111 is located in the middle position of the entire tread body 1. The intermediate tread block 111 includes multiple groups of transverse grooves 2. Each group of transverse grooves 2 includes a transverse groove one 21 and a transverse groove two 22. The transverse groove one 21 and the transverse groove two 22 are both in the shape of a grenade and are arranged in reverse inclination.

[0047] As Figure 3As shown, the side tread blocks 112 include a left tread block 10 and a right tread block 13. The left tread block 10 and the right tread block 13 are respectively arranged on the left and right sides of the middle tread block 111, and are distributed in a reverse symmetrical shape. Both the left tread block 10 and the right tread block 13 include multiple groups of first tread blocks 18. Multiple groups of the first tread blocks 18 all adopt an F-shaped structure 3, and a first tread groove 4 with a multi-layer stepped structure is arranged between adjacent first tread blocks 18.

[0048] A first longitudinal groove 5 is arranged between the middle tread block 111 and the side tread blocks 112. The first longitudinal groove 5 includes a left groove 51 and a right groove 52. Snow claws 6 arranged in a staggered manner are arranged in both the left groove 51 and the right groove 52. The snow claws 6 are connected to the middle tread block 111 or the side tread blocks 112. Specifically, the tails of multiple snow claws 6 are fixedly installed on both sides of the middle tread block 111. Multiple snow claws 6 on the left tread block 10 are fixedly installed on the side of the left tread block 10 close to the middle tread block 111, and the snow claws 6 on the right tread block 13 are fixedly installed on the side of the right tread block 13 close to the middle tread block 111.

[0049] Furthermore, as Figure 3 shown, a reverse wedge-shaped inclined surface structure 7 is arranged on the side part of the middle tread block 111. The inclined surface structure 7 adopts a gradient design. The depth of the inclined surface structure 7 gradually changes from 0 mm to 1 / 2 of the depth of the first longitudinal groove 5, aiming to increase the area of the tire center region and the snow steering function.

[0050] Furthermore, multiple steel sheets 8 with different forms and different types of twists are embedded in both the middle tread unit 11 and the shoulder tread unit 12.

[0051] Furthermore, as Figure 12 shown, the transverse groove 2 gradually changes from thick to thin, and its depth also shows a gradient change, with a gradient depth of 2 - 3 mm. Specifically, one end of the first transverse groove 21 close to the left groove 51 is short and thick, and the end close to the right groove 52 is thin and long. The depth of the thin end is less than that of the thick end, and the depth gradient from the thin end to the thick end is 2 - 3 mm. Similarly, one end of the second transverse groove 22 close to the right groove 52 is short and thick, and the end close to the left groove 51 is thin and long. The depth gradient from the thin end to the thick end is 2 - 3 mm.

[0052] In the thin and long part of the transverse groove 2, a zigzag steel sheet 8 with a depth of 2 - 3 mm is embedded. The transverse groove 2 and the steel sheet 8 therein together form the main groove of the middle tread block 111, enabling it to have excellent snow discharge performance and drainage performance, and increasing the traction performance of the tire on the snow-covered road surface.

[0053] As Figure 12As shown, the groove wall angle of the transverse groove 2 is 3 - 8°, and the bottom of the transverse groove 2 has a chamfered arc with a radius of R0.5mm - R2.5mm. The U-shaped groove design of the chamfered arc at the bottom of the groove increases the bottom width of the groove and improves the snow removal performance.

[0054] Further, as Figure 3 , Figure 7 and Figure 13 shown, the first tread block 18 adopts an F-shaped structure 3. In the Latin alphabet, the pictographic origin of F is a feather. The F-shaped structure 3 includes a third transverse groove 31, a fourth transverse groove 32, and a second longitudinal groove 33. The second longitudinal groove 33 intersects with the third transverse groove 31 and is embedded in the third transverse groove 31, with an embedding depth of 2.8 - 3.5mm. The depth and width of the second longitudinal groove 33 both gradually change from large to small. The gradually changing depth of the second longitudinal groove 33 gradually changes from 2.5 - 3.5mm near the position of the third transverse groove 31 to 1.5 - 2.0mm, aiming to prevent the tread block from being divided too fragmented, while ensuring the high rigidity of the overall tread block and realizing the wear resistance of the tread pattern.

[0055] The fourth transverse groove 32 is located at the middle position of the second longitudinal groove 33 and is embedded in the second longitudinal groove 33. The depth of the fourth transverse groove 32 is in a gradually changing form, and the deepest part of the fourth transverse groove 32 is 1.0 - 1.5mm shallower than the deepest part of the third transverse groove 31.

[0056] The groove wall angles of the third transverse groove 31, the fourth transverse groove 32, and the second longitudinal groove 33 are 2° - 8°, and the chamfered arc at the bottom of the groove is in the range of R0.5mm - R2.5mm, aiming to increase the bottom width of the groove and take into account both snow removal and the stiffness of the tread block.

[0057] The second longitudinal groove 33 is connected to a plurality of zigzag steel sheets 8. The steel sheets 8 are embedded in the second longitudinal groove 33, with an embedding depth of 1.5 - 2.5mm.

[0058] The F-shaped design divides the first tread block 18 into three regions, and each region is distributed with different forms and different types of zigzag steel sheets 8. The depth of the steel sheets 8 is also designed in various forms. The overall layout takes into account aspects such as snow removal performance, wear resistance, and high stiffness of the tread block. Through multiple tests, it is obtained that the Tg point of the tread structure of this tire is in the range of -36.8°C to -42.9°C, meeting the temperature range requirements of all-season tires in North America. After comparison and verification with a well-known brand, the snow acceleration and snow braking are 102.2% and 100.9% of a well-known brand respectively (as shown in Table 1 and Table 3).

[0059] Further, as Figure 14As shown, the pattern groove 1-4 is zigzag, and a first step 41 is provided therein. The first step 41 is formed by extending upward 3.5-4.5 mm along the bottom of the pattern groove 1-4. At both ends of the pattern groove 1-4, a second step 42 and a third step 43 with a height of 1.5-2.5 mm are respectively provided. The first step 41, the second step 42 and the third step 43 are in a stepped shape, and the height difference is 1.0-3.0 mm, aiming to improve the overall rigidity of the tread block. When braking, traction and steering, the deformation of the pattern groove is reduced, and the high wear resistance of the tread block is improved.

[0060] Furthermore, the width of the pattern groove 1-4 near the middle tread block 111 is greater than its width near the shoulder pattern unit 12. Specifically, the width of the pattern groove 1-4 near one end of the longitudinal groove 1-5 is 4.5-7.5 mm, and the width near the shoulder pattern unit 12 is 3.0-5.5 mm, aiming to improve the snow removal and drainage performance. After comparison and verification with a well-known brand, the wet braking performance is 100.3% of that of an internationally well-known brand (as shown in Table 1). At the same time, the stepped design inside the groove also reduces the pump noise performance.

[0061] Furthermore, as Figure 8 、 Figure 9 and Figure 17As shown, the bionic snow claw 6 is triangular. The radian at the bottom of the snow claw 6 is smaller than that at the top (the above radian direction is referenced by the shape of the snow claw 6 on the left tread block 10). The snow claw 6 protrudes upward from the bottoms of the left groove 51 and the right groove 52, and its width extends outward to 1 / 2 of the transverse width of the first longitudinal groove 5, forming strong snow-gripping and snow-discharging performance. The height of the root of the snow claw 6 is greater than the height of the snow claw 6 extending outward to the first longitudinal groove 5. The height of the root of the snow claw 6 is 2.5 - 3.0 mm, and the height near the center position of the left groove 51 or the right groove 52 is 1.0 - 1.5 mm. Specifically, the width of the tail end of the snow claw 6 is 3.5 - 4.5 mm, preferably 3.8 mm. The upper arc surface and the lower arc surface of the snow claw 6 are transitioned by an arc, and the radius of the arc is 0.2 mm. The purpose is to improve the snow grip and traction of the tire during operation, and discharge the snow from the groove more timely. Combining with the E* - 25°C data in terms of formula, this data has the lowest value at - 25°C, indicating that the tire can better fit the snow surface in the microscopic state, and in the low-temperature state of (-20°C) - (-23°C), the hardness of this structure is the lowest. Therefore, through the ASTM F1805 snow traction test, the maximum and most difficult snow traction index of this tread structure is 113.5, the snow traction index of ordinary small specifications is 114.6, and the limit value of ASTM F1805 is 112, indicating that the entire series of this product passes the ASTM F1805 snow test (as shown in Table 2 and Table 3). At the same time, the design of the "snow claw" element can also disrupt the airflow and reduce the cavity noise.

[0062] Furthermore, as Figure 4 , Figure 15 and Figure 16 shown, the shoulder tread unit 12 includes a fifth transverse groove 121 and a sixth transverse groove 122. The fifth transverse groove 121 does not extend to the shoulder tread cut-off position 9, and the sixth transverse groove 122 extends to the shoulder tread cut-off position 9. Both the fifth transverse groove 121 and the sixth transverse groove 122 are zigzag and transition from a semi-closed state at the front end to a full groove depth state. The semi-closed design at the front end not only ensures the penetration and snow-discharging performance of the fifth transverse groove 121 and the sixth transverse groove 122, but also reduces the pumping noise of the two.

[0063] As Figure 15 and Figure 16As shown, a longitudinal groove three 14 is provided between the left tread block 10 and the shoulder tread unit 12, and a longitudinal groove four 15 is provided between the right tread block 13 and the shoulder tread unit 12. The depth of the transverse groove five 121 and the transverse groove six 122 near one end of the longitudinal groove three 14 or the longitudinal groove four 15 is 3.5 - 4.5 mm, and the width accounts for about 18% of the transverse direction of the entire shoulder tread unit 12. After comparison and verification with a well-known brand, under the condition of 80 km / h, the indoor noise test is 102.1% of that of a well-known brand.

[0064] Different numbers of 3D zigzag steel sheets 8 and small grooves 16 are also arranged on the shoulder tread unit 12, and the small grooves 16 and the steel sheets 8 are arranged in a cross pattern, thereby enhancing the strength of the tire tread.

[0065] Further, as Figure 10 shown, the zigzag angle of the steel sheet 8 is 45°, the steel sheet 8 is wavy, and the end of the steel sheet 8 is connected with a transverse or inclined extension part. The design of the zigzag 3D steel sheet 8 increases the rigidity and wetland performance of the tire tread, improves the grip, optimizes the drainage and snow removal performance, disperses stress, reduces deformation, enhances the snow braking ability, and at the same time the transverse or inclined extension part can also reduce the side slip tendency during turning, improve the cornering stability, can adapt to complex snow road conditions, enhance the durability, and extend the service life. The wear resistance index of this tire can reach 700.

[0066] The diverse and variable zigzag steel sheet 8 design language is adopted in the entire tread structure, and excellent performance can be shown on wet, snowy, and dry road surfaces, meeting the usage requirements throughout the year in the North American region.

[0067] Further, as Figure 11 and Figure 18 shown, downwardly inclined triangular cut surfaces 17 are provided at the ends of the transverse groove one 21, the transverse groove two 22, the transverse groove three 31, the transverse groove four 32, and the tread groove one 4. The setting of the triangular cut surfaces 17 can further optimize the drainage performance, increase the edge effect when the tire contacts the ground, enhance the grip, and at the same time can also reduce noise and improve the handling stability.

[0068] Further, as Figure 19 shown, the contour shoulder of the tire adopts an inverted arc design with a radius of R20 mm - R25 mm, and the upper sidewall arc adopts a tangent + arc form, optimizing the stress distribution, enhancing the durability, ensuring the lateral stiffness and steering performance of the shoulder tread unit 12 of the tire. At the same time, after comparison and verification, its dry handling is better than that of a well-known brand, with a score of 6.75+.

[0069] The above tread structure increases the ground contact width, with the ratio increased to 86%-89%. At the same time, the crown arc radius and the corresponding structure are adjusted to ensure that the imprint is square (as Figure 20 shown), improving the tire's ground contact area, increasing the edge effect of the transverse grooves of the tread pattern unit 12 on the tire shoulder, and increasing the number of tread blocks within the effective ground contact area, thereby enhancing the snow traction performance, as well as the dry grip and handling performance. After comparison and verification with a well-known brand, the dry braking distance is 111.5% of that of a well-known brand (as shown in Table 1).

[0070] Table 1

[0071]

[0072] Table 2 ASTM F1805-20 Snow Traction Test Data

[0073]

[0074] Table 3

[0075]

[0076] Table 1 shows the comparison of the all-season tire tread structure of this application with a well-known international brand in terms of dry handling stability, wet braking, dry braking, snow acceleration, and snow braking performance. It can be seen from Table 1 that the dry handling stability of the all-season tire tread structure is better than that of a well-known international brand, with a score of 6.75+; the all-season tire tread structure is better than the well-known international brand in terms of wet braking, dry braking, snow acceleration, and snow braking performance, which are 100.3%, 111.5%, 102.2%, and 100.9% of the well-known international brand respectively.

[0077] Table 2 shows the ASTM F1805-20 snow traction test data of the all-season tire tread structure of this application. The traction indices of the largest and most difficult-to-pass size 285 / 45R22 114HXL are 113.7, 112.4, 114.7, 113.2, with an average value of 113.5. The traction indices of the common small size 225 / 50R17 98V are 115.1, 115.8, 113.5, 114.0, with an average value of 114.6. The limit of ASTM F1805 is 112, indicating that all the above products have passed the ASTM F1805 snow test and all have strong snow traction performance, meeting the tire usage requirements in winter snowfall areas such as North America.

[0078] Table 3 shows the comparison of the seasonal tire tread structure of this application with a well-known international brand in terms of room temperature Shore A hardness, low temperature Shore A hardness, and DMA temperature scanning. From Table 3, it can be seen that the Tg point of the tire tread structure is in the range of -36.8°C to -42.9°C, meeting the temperature range requirements of all-season tires in regions such as North America. At the same time, combined with the E* -25°C data, this data has the lowest value at -25°C, indicating that the tire can better fit the snow surface at the microscopic level. And in the low temperature state of (-20°C) - (-23°C), the hardness of this structure is the lowest, being 70, which is beneficial for the tire to better fit the snow surface, increase the friction with the snow surface, and improve the traction force.

[0079] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "left", "right", "upper", "lower", "top", "bottom", "front", "rear", "inner", "outer", "back", "middle", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus cannot be understood as a limitation to the present invention.

[0080] However, the above are only specific embodiments of the present invention, and the scope of implementation of the present invention cannot be limited thereby. Therefore, the replacement of equivalent components or the equivalent changes and modifications made according to the scope of protection of the present invention shall still fall within the scope covered by the claims of the present invention.

Claims

1. A four-season tire tread structure adapted for driving on snow, comprising a tread body (1), the tread body (1) including a central tread unit (11) and shoulder tread units (12), the shoulder tread units (12) being disposed on both sides of the central tread unit (11), characterized in that, The middle tread unit (11) includes a middle tread block (111) and side tread blocks (112). The side tread blocks (112) are distributed on both sides of the middle tread block (111). The middle tread block (111) includes multiple groups of transverse grooves (2). Each group of the transverse grooves (2) has a grenade-like structure and is arranged in opposite directions. The side tread blocks (112) include multiple groups of first tread blocks (18). The first tread blocks (18) adopt an F-shaped structure (3). Between adjacent first tread blocks (18), there are multiple layers of stepped tread grooves one (4). There is a first longitudinal groove (5) between the middle tread block (111) and the side tread blocks (112). In the first longitudinal groove (5), there are snow claws (6) arranged in a staggered manner. The snow claws (6) are connected to the middle tread block (111) or the side tread blocks (112).

2. The tread structure of a four-season tire adapted for driving on snow according to claim 1, characterized in that, On the side part of the middle tread block (111), there is a wedge-shaped inclined surface structure (7) arranged in the opposite direction. The depth of the inclined surface structure (7) gradually changes from 0 mm to half of the depth of the first longitudinal groove (5).

3. The tread structure of a four-season tire adapted for driving on snow according to claim 1, characterized in that, A plurality of zigzag steel sheets (8) are embedded in both the middle tread unit (11) and the shoulder tread unit (12).

4. A four-season tire tread structure adapted for snow driving according to claim 3, characterized in that, The transverse grooves (2) gradually change from thick to thin, with a gradual change depth of 2 - 3 mm. The steel sheets (8) with a depth of 2 - 3 mm are embedded in the transverse grooves (2). The groove wall angle of the transverse grooves (2) is 3 - 8°. The bottom of the transverse grooves (2) has a rounded arc of R0.5 mm - R2.5 mm.

5. A tread structure of a four-season tire adapted for driving on snow, characterized in that, The F-shaped structure (3) includes a third transverse groove (31), a fourth transverse groove (32), and a second longitudinal groove (33). The second longitudinal groove (33) intersects with the third transverse groove (31) and is embedded in the third transverse groove (31), with an embedding depth of 2.8 - 3.5 mm. The depth and width of the second longitudinal groove (33) both gradually change from large to small. The fourth transverse groove (32) is located in the middle of the second longitudinal groove (33) and is embedded in the second longitudinal groove (33). The depth of the fourth transverse groove (32) is in a gradual change. The deepest part of the fourth transverse groove (32) is 1.0 - 1.5 mm shallower than the deepest part of the third transverse groove (31).

6. The tread structure of a four-season tire adapted for driving on snow according to claim 1, characterized in that, The tread groove one (4) is zigzag. There is a first step (41) inside it. The first step (41) extends upward 3.5 - 4.5 mm along the bottom of the tread groove one (4). At both ends of the tread groove one (4), there are a second step (42) and a third step (43) with a height of 1.5 - 2.5 mm respectively. The first step (41), the second step (42), and the third step (43) are in a stepped shape.

7. A tread structure of a four-season tire adapted for driving on snow, characterized in that, The width of the tread groove one (4) near the middle tread block (111) is greater than its width near the shoulder tread unit (12).

8. A tread structure of a four-season tire adapted for driving on snow, characterized in that, The snow claw (6) is triangular, the radian of the bottom of the snow claw (6) is smaller than that of the top, the width of the snow claw (6) extends to 1 / 2 of the transverse width of the first longitudinal groove (5), and the height of the root of the snow claw (6) is greater than the height of the snow claw (6) extending outward to the first longitudinal groove (5).

9. A tread structure of a four-season tire adapted for driving on snow, characterized in that, The shoulder pattern unit (12) includes a fifth transverse groove (121) and a sixth transverse groove (122). The fifth transverse groove (121) does not extend to the shoulder pattern cut-off position (9), and the sixth transverse groove (122) extends to the shoulder pattern cut-off position (9). Both the fifth transverse groove (121) and the sixth transverse groove (122) are zigzag and transition from a front-end semi-closed state to a full groove depth state.

10. The tread structure of a four-season tire adapted for snow driving according to claim 3, characterized in that, The zigzag angle of the steel sheet (8) is 45°.

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