Tire tread structure
By designing longitudinal grooves and specific shapes of recesses and grooves in the tire tread structure, the problem of insufficient grip of new energy vehicles is solved, and the grip performance of tires under various road conditions is improved, ensuring safety.
Patent Information
- Application Number
- CN202422495844.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-15
- Publication Date
- 2025-07-11
- Estimated Expiration
- 2034-10-15
AI Technical Summary
The existing tire tread structure cannot meet the grip needs of new energy vehicles, affecting the driving experience and the safety of riders.
A tire tread structure is designed, including multiple longitudinal grooves and recesses and grooves of specific shapes, to improve grip performance by draining, guiding, balancing rigidity and cutting water film.
It has good grip performance on both dry and wet roads, reducing the braking distance when the car is braked and ensuring the safety of the rider.
Smart Images
Figure CN223085760U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of tires, and in particular, to a tire tread structure and a tire having the same. Background Art
[0002] At present, with the rapid development of new energy vehicles, a large number of traditional fuel vehicles are being replaced by new energy vehicles. At the same time, as the only contact component between the vehicle and the driving surface, the tread pattern structure on the surface of the tire has a direct impact on various driving performances of the vehicle.
[0003] However, a large number of existing new energy vehicles use traditional fuel vehicle tires. In fact, due to the completely different power systems between new energy vehicles and traditional fuel vehicles, the requirements for tire performance are higher, especially the grip performance of the tire, which not only affects the driving experience of the driver, but also relates to the braking distance of the vehicle, seriously affecting the personal safety of passengers. Summary of the Utility Model
[0004] The main purpose of the utility model is to provide a tire tread structure to solve the problem that the tire tread structure in the prior art cannot meet the grip requirements of new energy vehicles.
[0005] To achieve the above object, the utility model provides a tire tread structure, including: a plurality of longitudinal grooves, each longitudinal groove extending along the circumferential direction of the tire, and the plurality of longitudinal grooves being spaced apart along the width direction of the tire to divide the tread into two shoulder tread portions and an intermediate tread portion located between the two shoulder tread portions; a first recess, disposed on the intermediate tread portion, one end of the first recess extending to one side of the intermediate tread portion to communicate with the longitudinal groove, and a preset distance being provided between the other end of the first recess and the other side of the intermediate tread portion; a first groove, disposed on the intermediate tread portion; wherein, the first groove has a first sub-groove and a second sub-groove that communicate with each other, the first sub-groove being located on the bottom wall of the first recess, the second sub-groove being located outside the first recess, and one end of the first sub-groove far from the second sub-groove communicating with the longitudinal groove.
[0006] Further, one end of the first recess communicating with the longitudinal groove is a communication end, and along the direction from the communication end to the other end of the first recess, the width of the first recess gradually decreases.
[0007] Further, the plurality of intermediate tread patterns include: a central tread pattern, at least a part of the central tread pattern coincides with the central plane S of the tire, and the central tread pattern has a width W1; an inner crown tread pattern, located between the central tread pattern and the shoulder tread pattern, the inner crown tread pattern is arranged closer to the inner side of the tire relative to the central tread pattern, and the inner crown tread pattern has a width W2; wherein, first recesses are provided on both the central tread pattern and the inner crown tread pattern, the first recess on the central tread pattern is a central recess, and the first recess on the inner crown tread pattern is an inner recess, and the lengths L1 of the central recess and L2 of the inner recess satisfy: 0.25W1 ≤ L2 ≤ 0.5W1, 0.5W2 ≤ L2 ≤ 0.75W2, and L1 < L2; the extending direction of the inner recess forms a first angle A1 with the width direction of the tire, and the first angle A1 satisfies: 8° ≤ A1 ≤ 20°.
[0008] Further, the tire tread structure further includes: a second recess, provided on the inner crown tread pattern, one end of the second recess extends to one side of the inner crown tread pattern to communicate with the longitudinal groove, and there is a preset distance between the other end of the second recess and the other side of the inner crown tread pattern; wherein, the first recess and the second recess respectively communicate with two longitudinal grooves adjacent to the inner crown tread pattern, the extending direction of the second recess forms a second angle A2 with the width direction of the tire, and the second angle A2 satisfies: 19° ≤ A2 ≤ 25°, and the length L3 of the second recess and the width W2 satisfy: 0.6W2 ≤ L3 ≤ 0.8W2.
[0009] Further, the tire tread structure further includes: an outer crown tread pattern, the outer crown tread pattern is arranged closer to the outer side of the tire relative to the central tread pattern, and the outer crown tread pattern has a width W3; a third recess, provided on the outer crown tread pattern, one end of the third recess extends to one side of the outer crown tread pattern to communicate with the longitudinal groove, and there is a preset distance between the other end of the third recess and the other side of the outer crown tread pattern; wherein, there are a plurality of the third recesses, and the plurality of third recesses are arranged at intervals in the circumferential direction of the tire to divide the outer crown tread pattern into a plurality of outer crown tread blocks; a second groove, provided on the outer crown tread block, one end of the second groove communicates with a longitudinal groove adjacent to the outer crown tread pattern, and there is a preset distance between the other end of the second groove and another longitudinal groove adjacent to the outer crown tread pattern; wherein, the length L4 of the second groove and the width W3 satisfy: 0.25W3 ≤ L4 ≤ 0.5W3, and the width W4 of the second groove satisfies: 0.4 mm ≤ W4 ≤ 0.8 mm.
[0010] Further, the tire tread structure further includes: strip-shaped recesses disposed on the shoulder tread portion, with a preset distance between the end of the strip-shaped recess and the side surface of the shoulder tread portion. There are multiple strip-shaped recesses, which are arranged at intervals in the circumferential direction of the tire to divide the shoulder tread portion into multiple shoulder tread blocks; communication grooves disposed on the shoulder tread blocks, and the longitudinal grooves adjacent to the shoulder tread portion are communicated with the shoulder of the tire through the communication grooves.
[0011] Further, the two shoulder tread portions include: an inner shoulder tread portion disposed closer to the inner side of the tire relative to the central plane S, and the communication groove disposed on the inner shoulder tread portion is a straight groove; an outer shoulder tread portion disposed closer to the outer side of the tire relative to the central plane S, and the communication groove disposed on the outer shoulder tread portion includes a first sub-communication groove, a second sub-communication groove, and a third sub-communication groove that are sequentially communicated. One end of the first sub-communication groove far from the second sub-communication groove is communicated with the longitudinal groove adjacent to the outer shoulder tread portion, and one end of the third sub-communication groove far from the second sub-communication groove is communicated with the shoulder of the tire; wherein, in the direction from the first sub-communication groove to the third sub-communication groove, the width of the second sub-communication groove gradually decreases, the extending direction of the first sub-communication groove and the extending direction of the third sub-communication groove are arranged at an angle, and the depth of the third sub-communication groove is less than the depth of the second sub-communication groove.
[0012] Further, the tire tread structure further includes: a first strip-shaped cut angle disposed on the inner wall of the communication groove; and / or, on the inner wall of the strip-shaped recess; and / or, on the inner wall of the second recess. The first strip-shaped cut angle includes a first sub-strip-shaped cut angle and a second sub-strip-shaped cut angle that are mutually communicated, and the second sub-strip-shaped cut angle is disposed closer to the central plane S than the first sub-strip-shaped cut angle; wherein, in the direction from the central plane S to the shoulder tread portion, the width of the second sub-strip-shaped cut angle gradually increases, the depth of the second sub-strip-shaped cut angle gradually increases, the width of the first sub-strip-shaped cut angle gradually decreases, and the depth of the first sub-strip-shaped cut angle gradually decreases.
[0013] Further, the strip-shaped recess on the inner shoulder tread portion is an inner strip-shaped recess, and the strip-shaped recess on the outer shoulder tread portion is an outer strip-shaped recess. A first strip-shaped cut angle is disposed on the inner wall of the inner strip-shaped recess; a third groove is further disposed on the inner shoulder tread portion, and the third groove is located between the inner strip-shaped recess and the longitudinal groove. The inner strip-shaped recess is communicated with the longitudinal groove through the third groove, and the width W5 of the third groove satisfies: 0.4 mm ≤ W5 ≤ 0.8 mm; a second strip-shaped cut angle is disposed on the inner wall of the outer strip-shaped recess, and the second strip-shaped cut angle surrounds the outer strip-shaped recess and is located at one end of the outer strip-shaped recess closer to the central plane S.
[0014] Furthermore, the tire tread structure includes a plurality of pattern groups arranged circumferentially along the tire. The pitches P1 of the first pattern group, P2 of the second pattern group, P3 of the third pattern group, P4 of the fourth pattern group, and P5 of the fifth pattern group among the plurality of pattern groups satisfy: 1.14P1 ≤ P2 ≤ 1.146P1, 1.284P1 ≤ P3 ≤ 1.3P1, 1.4P1 ≤ P4 ≤ 1.46P1, 1.57P1 ≤ P5 ≤ 1.6P1; and / or, the contact surface between the tire and the driving surface has a width TAW. In the direction from the inner side to the outer side of the tire, the plurality of longitudinal grooves include a first longitudinal groove, a second longitudinal groove, a third longitudinal groove, and a fourth longitudinal groove. The widths w1 of the first longitudinal groove, w2 of the second longitudinal groove, w3 of the third longitudinal groove, w4 of the fourth longitudinal groove, and the width TAW satisfy: 0.061TAW ≤ w1 ≤ 0.067TAW, 0.071TAW ≤ w2 ≤ 0.077TAW, 0.075TAW ≤ w3 ≤ 0.081TAW, 0.045TAW ≤ w4 ≤ 0.051TAW; the width W6 of the inner shoulder pattern part, the width W2 of the inner crown pattern part, the width W1 of the center pattern part, the width W3 of the outer crown pattern part, the width W7 of the outer shoulder pattern part, and the width TAW satisfy: 0.174TAW ≤ W6 ≤ 0.204TAW, 0.113TAW ≤ W2 ≤ 0.133TAW, 0.113TAW ≤ W1 ≤ 0.144TAW, 0.105TAW ≤ W3 ≤ 0.165TAW, 0.157TAW ≤ W7 ≤ 0.187TAW.
[0015] Applying the technical solution of the present utility model, a plurality of longitudinal grooves of the tire tread structure extend along the circumferential direction of the tire, and the plurality of longitudinal grooves are arranged at intervals in the width direction of the tire, so that the tread is divided into two shoulder tread portions and an intermediate tread portion located between the two shoulder tread portions. The first concave portion is provided on the intermediate tread portion, and one end of the first concave portion extends to one side surface of the intermediate tread portion to communicate with the longitudinal groove, and there is a preset distance between the other end of the first concave portion and the other side surface of the intermediate tread portion; the first groove is provided on the intermediate tread portion. Among them, the first groove has a first sub-groove and a second sub-groove that communicate with each other. The first sub-groove is located on the bottom wall of the first concave portion, and the second sub-groove is located outside the first concave portion. One end of the first sub-groove far from the second sub-groove communicates with the longitudinal groove. First of all, the arrangement of the plurality of longitudinal grooves can play a role in draining and guiding water when the tire is traveling on a wet road surface (that is, the water liquid between the tread and the driving surface can be squeezed into the longitudinal grooves), so as to avoid excessive water liquid between the tire tread and the driving surface, resulting in a decrease in the friction coefficient between the tire and the driving surface, and initially improving the grip performance of the tire; secondly, the first concave portion provided on the core contact area (intermediate tread portion) between the tread and the driving surface can play a role in balancing rigidity and promoting the deformation of the intermediate tread portion, so that the intermediate tread portion can better bite with the driving surface, further improving the grip performance of the tire, and the first sub-groove located on the bottom wall of the first concave portion can balance the rigidity at the first concave portion from the root of the intermediate tread portion and at a deeper level, further improving the biting reliability of the intermediate tread portion. At the same time, the second sub-groove and the edge of the first concave portion can actually play a role in cutting the water film (during the rolling process of the tire, the second sub-groove and the edge of the first concave portion will be squeezed to "cut" the water film between the tread and the driving surface), so as to avoid the formation of a complete water film and further improve the grip performance of the tire on a wet road surface. It can be seen that the tire adopting the tire tread structure in the present application has good grip performance whether on a dry road surface or a wet road surface, greatly meets the higher tire grip requirements of new energy vehicles, and further solves the problem that the tire tread structure in the prior art cannot meet the grip requirements of new energy vehicles, reduces the braking distance when the vehicle brakes, and ensures the personal safety of the passengers and drivers. BRIEF DESCRIPTION OF THE DRAWINGS
[0016] The accompanying drawings forming a part of this application are used to provide a further understanding of the present utility model. The schematic embodiments and descriptions thereof of the present utility model are used to explain the present utility model and do not constitute an improper limitation of the present utility model. In the drawings:
[0017] Figure 1 A partial front view showing an embodiment of the tire tread structure according to the present utility model is shown;
[0018] Figure 2shows Figure 1 a partially enlarged schematic view of the tread structure in
[0019] Figure 3 shows Figure 1 a cross-sectional schematic view of the first longitudinal groove of the tread structure in
[0020] Figure 4 shows Figure 1 a cross-sectional schematic view of the second and third longitudinal grooves of the tread structure in
[0021] Figure 5 shows Figure 1 a cross-sectional schematic view of the fourth longitudinal groove of the tread structure in
[0022] Figure 6 shows Figure 1 a cross-sectional schematic view of the first recess of the tread structure in
[0023] Figure 7 shows Figure 1 a cross-sectional schematic view of the strip-shaped recess provided on the inner shoulder tread portion of the tread structure in
[0024] Figure 8 shows Figure 1 a cross-sectional schematic view of the communicating groove provided on the inner shoulder tread portion of the tread structure in
[0025] Figure 9 shows Figure 1 a cross-sectional schematic view of the communicating groove provided on the outer shoulder tread portion of the tread structure in
[0026] Figure 10 shows Figure 1 a cross-sectional schematic view of the strip-shaped recess provided on the outer shoulder tread portion of the tread structure in
[0027] Among them, the above-mentioned drawings include the following reference numerals:
[0028] 1. Longitudinal groove; 101. First longitudinal groove; 102. Second longitudinal groove; 103. Third longitudinal groove; 104. Fourth longitudinal groove; 2. Shoulder tread part; 201. Inner shoulder tread part; 202. Outer shoulder tread part; 3. First recess; 4. First groove; 401. First sub-groove; 402. Second sub-groove; 5. Center tread part; 6. Inner crown tread part; 7. Second recess; 8. Outer crown tread part; 9. Third recess; 10. Second groove; 11. Strip-shaped recess; 12. Connecting groove; 121. First sub-connecting groove; 122. Second sub-connecting groove; 123. Third sub-connecting groove; 13. First strip-shaped cut angle; 131. First sub-strip-shaped cut angle; 132. Second sub-strip-shaped cut angle; 14. Third groove; 15. Second strip-shaped cut angle; 16. Pattern group. Detailed implementation mode
[0029] It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments may be combined with each other. The following will describe the present invention in detail with reference to the drawings and in combination with the embodiments.
[0030] It should be pointed out that, unless otherwise specified, all technical and scientific terms used in the present application have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present application belongs.
[0031] In the present invention, unless otherwise stated, the orientation terms such as "upper, lower" are usually in the direction shown in the drawings, or in the vertical, perpendicular or gravitational direction; similarly, for the convenience of understanding and description, "left, right" are usually left and right as shown in the drawings; "inner, outer" refer to the inner and outer of the contour of each component itself, but the above orientation terms do not limit the present invention.
[0032] In order to solve the problem that the tire tread structure in the prior art cannot meet the grip requirements of new energy vehicles, the present application provides a tire tread structure.
[0033] Such as Figures 1 to 10As shown, the tire tread structure includes a plurality of longitudinal grooves 1, a first recess 3, and a first groove 4. Each longitudinal groove 1 extends along the circumferential direction of the tire, and the plurality of longitudinal grooves 1 are arranged at intervals in the width direction of the tire, dividing the tread into two shoulder tread portions 2 and an intermediate tread portion located between the two shoulder tread portions 2. The first recess 3 is provided on the intermediate tread portion. One end of the first recess 3 extends to one side of the intermediate tread portion to communicate with the longitudinal groove 1, and there is a preset distance between the other end of the first recess 3 and the other side of the intermediate tread portion. The first groove 4 is provided on the intermediate tread portion. Among them, the first groove 4 has a first sub-groove 401 and a second sub-groove 402 that communicate with each other. The first sub-groove 401 is located on the bottom wall of the first recess 3, the second sub-groove 402 is located outside the first recess 3, and the end of the first sub-groove 401 away from the second sub-groove 402 communicates with the longitudinal groove 1.
[0034] Applying the technical solution of this embodiment, multiple longitudinal grooves 1 of the tire tread structure extend along the circumferential direction of the tire. The multiple longitudinal grooves 1 are arranged at intervals in the width direction of the tire, dividing the tread into two shoulder tread parts 2 and an intermediate tread part located between the two shoulder tread parts 2. The first recess 3 is provided on the intermediate tread part. One end of the first recess 3 extends to one side of the intermediate tread part to communicate with the longitudinal groove 1, and there is a preset distance between the other end of the first recess 3 and the other side of the intermediate tread part. The first groove 4 is provided on the intermediate tread part. Among them, the first groove 4 has a first sub-groove 401 and a second sub-groove 402 that communicate with each other. The first sub-groove 401 is located on the bottom wall of the first recess 3, and the second sub-groove 402 is located outside the first recess 3. The end of the first sub-groove 401 away from the second sub-groove 402 communicates with the longitudinal groove 1. First of all, the arrangement of the multiple longitudinal grooves 1 can play a role in draining and guiding water when the tire is driving on a wet road surface (that is, the water liquid between the tread and the driving surface can be squeezed into the longitudinal grooves 1), so as to avoid excessive water liquid between the tire tread and the driving surface, which may cause the reduction of the friction coefficient between the tire and the driving surface, and initially improve the grip performance of the tire. Secondly, the first recess 3 provided on the core contact area (intermediate tread part) between the tread and the driving surface can play a role in balancing rigidity and promoting the deformation of the intermediate tread part, so that the intermediate tread part can better bite with the driving surface, further improving the grip performance of the tire. The first sub-groove 401 located on the bottom wall of the first recess 3 can balance the rigidity at the first recess 3 from the root of the intermediate tread part and at a deeper level, further improving the biting reliability of the intermediate tread part. At the same time, the second sub-groove 402 and the edge of the first recess 3 can actually play a role in cutting the water film (during the rolling process of the tire, the second sub-groove 402 and the edge of the first recess 3 will be squeezed to "cut" the water film between the tread and the driving surface), so as to avoid the formation of a complete water film and further improve the grip performance of the tire on a wet road surface. It can be seen that the tire adopting the tire tread structure in this embodiment has good grip performance on both dry and wet roads, greatly meeting the higher tire grip requirements of new energy vehicles, thus solving the problem that the existing tire tread structure cannot meet the grip requirements of new energy vehicles, reducing the braking distance when the vehicle brakes, and ensuring the personal safety of passengers and drivers.
[0035] Such as Figure 1 and Figure 2As shown, one end of the first recess 3 communicating with the longitudinal groove 1 is the communicating end. Along the direction from the communicating end to the other end of the first recess 3, the width of the first recess 3 gradually decreases. In this way, while ensuring that the communicating end (the wider end) has sufficient high rigid balance ability, as the first recess 3 gradually decreases, its rigid balance ability also gradually weakens, thus avoiding the too small rigidity of the middle tread portion and affecting the wear resistance of the middle tread portion, and further extending the service life of the tire tread structure.
[0036] In this embodiment, the first recess 3 is actually a triangular recess, the first groove 4 is a straight groove, and the first groove 4 extends out through the vertex angle of the first recess 3 to form the second sub-groove 402.
[0037] As Figure 1 and Figure 2 As shown, the multiple middle tread portions include a center tread portion 5 and an inner crown tread portion 6. At least part of the center tread portion 5 coincides with the center plane S of the tire, and the center tread portion 5 has a width W1. The inner crown tread portion 6 is located between the center tread portion 5 and the shoulder tread portion 2. The inner crown tread portion 6 is arranged closer to the inner side of the tire relative to the center tread portion 5, and the inner crown tread portion 6 has a width W2. Among them, the first recess 3 is provided on both the center tread portion 5 and the inner crown tread portion 6. The first recess 3 on the center tread portion 5 is the center recess, and the first recess 3 on the inner crown tread portion 6 is the inner recess. The length L1 of the center recess and the length L2 of the inner recess satisfy: 0.25W1 ≤ L2 ≤ 0.5W1, 0.5W2 ≤ L2 ≤ 0.75W2, L1 < L2; the extending direction of the inner recess forms a first included angle A1 with the width direction of the tire, and the first included angle A1 satisfies: 8° ≤ A1 ≤ 20°. In this way, the above settings make the specifications, dimensions and deflection angles of the center recess and the inner recess more appropriate to match the actual grounding states of the center tread portion 5 and the inner crown tread portion 6 at different positions, further improving the rigid balance ability of the first recess 3, and further improving the grip performance of the tire.
[0038] In this embodiment, the length L1 of the center recess and the width W1 of the center tread portion 5 satisfy: L1 = 1 / 3W1; the length L2 of the inner recess and the width W2 of the center tread portion 5 satisfy: L2 = 2 / 3W2.
[0039] As Figure 1 and Figure 2As shown, the tire tread structure further includes a second recess 7. The second recess 7 is provided on the inner crown tread portion 6. One end of the second recess 7 extends to one side surface of the inner crown tread portion 6 to communicate with the longitudinal groove 1, and there is a preset distance between the other end of the second recess 7 and the other side surface of the inner crown tread portion 6. Among them, the first recess 3 and the second recess 7 are respectively communicated with two longitudinal grooves 1 adjacent to the inner crown tread portion 6. The extending direction of the second recess 7 is set at a second included angle A2 with the width direction of the tire, and the second included angle A2 satisfies: 19° ≤ A2 ≤ 25°. The length L3 of the second recess 7 and the width W2 satisfy: 0.6W2 ≤ L3 ≤ 0.8W2. In this way, the first recess 3 and the second recess 7 can balance the rigidity at both side edges of the inner crown tread portion 6 to improve the biting reliability between the inner crown tread portion 6 and the running surface, and further improve the grip performance of the tire. At the same time, the above size limitation ensures that the specifications, dimensions and deflection angle of the second recess 7 are more appropriate to match the actual grounding state of the inner crown tread portion 6.
[0040] In this embodiment, the length L3 of the second recess 7 and the width W2 satisfy: L3 = 0.75W2.
[0041] As Figure 1 and Figure 2As shown, the tire tread structure further includes an outer crown tread portion 8, a third recess 9, and a second groove 10. The outer crown tread portion 8 is disposed closer to the outer side of the tire relative to the central tread portion 5, and the outer crown tread portion 8 has a width W3. The third recess 9 is provided on the outer crown tread portion 8. One end of the third recess 9 extends to one side of the outer crown tread portion 8 to communicate with the longitudinal groove 1, and there is a preset distance between the other end of the third recess 9 and the other side of the outer crown tread portion 8; wherein, there are multiple third recesses 9, and the multiple third recesses 9 are arranged at intervals in the circumferential direction of the tire to divide the outer crown tread portion 8 into multiple outer crown tread blocks. The second groove 10 is provided on the outer crown tread block. One end of the second groove 10 communicates with one longitudinal groove 1 adjacent to the outer crown tread portion 8, and there is a preset distance between the other end of the second groove 10 and the other longitudinal groove 1 adjacent to the outer crown tread portion 8. Among them, the length L4 of the second groove 10 and the width W3 satisfy: 0.25W3 ≤ L4 ≤ 0.5W3, and the width W4 of the second groove 10 satisfies: 0.4 mm ≤ W4 ≤ 0.8 mm. In this way, the above settings of the third recess 9 and the second groove 10 can balance the rigidity of the outer crown tread portion 8 to ensure that the outer crown tread portion 8 can stably bite with the driving surface, further improving the grip performance of the tire. At the same time, the above size limitations of the third recess 9 and the second groove 10 can ensure that the rigidity balancing ability of the third recess 9 and the second groove 10 is more appropriate to match the actual grounding state of the outer crown tread portion 8.
[0042] In this embodiment, the width W4 of the second groove 10 is 6 mm. Actually, during the tire molding process, it is a fine groove directly molded by a tire mold provided with a 6-mm steel sheet. The second groove 10 actually has a relatively weak rigidity balancing ability for the outer crown tread portion 8, but can play a good role in cutting the water film.
[0043] In this embodiment, the third recess 9 adopts a recess design with a larger width and a shorter length to achieve a good rigidity balancing ability.
[0044] Such as Figure 1 and Figure 2As shown, the tire tread structure further includes strip-shaped recesses 11 and connecting grooves 12. The strip-shaped recesses 11 are provided on the shoulder tread portion 2. There is a preset distance between the end of the strip-shaped recess 11 and the side surface of the shoulder tread portion 2. There are multiple strip-shaped recesses 11, and the multiple strip-shaped recesses 11 are arranged at intervals in the circumferential direction of the tire to divide the shoulder tread portion 2 into multiple shoulder tread blocks. The connecting grooves 12 are provided on the shoulder tread blocks, and the longitudinal groove 1 adjacent to the shoulder tread portion 2 is communicated with the shoulder of the tire through the connecting grooves 12. In this way, the water liquid located between the tread and the running surface can finally flow to the outside of the tire through the connecting grooves 12 to avoid water liquid accumulation, further improving the wet skid resistance of the tire. The setting of the strip-shaped recesses 11 is beneficial to balancing the rigidity of the shoulder tread portion 2, enabling the shoulder tread portion 2 to also stably engage with the running surface, further improving the grip performance of the tire.
[0045] As Figure 1 and Figure 2 As shown, the two shoulder tread portions 2 include an inner shoulder tread portion 201 disposed closer to the inner side of the tire relative to the central plane S, and the connecting groove 12 provided on the inner shoulder tread portion 201 is a straight groove. An outer shoulder tread portion 202 disposed closer to the outer side of the tire relative to the central plane S, and the connecting groove 12 provided on the outer shoulder tread portion 202 includes a first sub-connecting groove 121, a second sub-connecting groove 122, and a third sub-connecting groove 123 that are sequentially connected. One end of the first sub-connecting groove 121 far from the second sub-connecting groove 122 is communicated with the longitudinal groove 1 adjacent to the outer shoulder tread portion 202, and one end of the third sub-connecting groove 123 far from the second sub-connecting groove 122 is communicated with the shoulder of the tire. Among them, in the direction from the third sub-connecting groove 123 to the first sub-connecting groove 121, the width of the second sub-connecting groove 122 gradually decreases, and the extending direction of the first sub-connecting groove 121 and the extending direction of the third sub-connecting groove 123 are arranged at an angle. The depth of the first sub-connecting groove 121 is less than the depth of the second sub-connecting groove 122. In this way, in this embodiment, the connecting groove on the outer shoulder tread portion 202 is optimized. On the one hand, the appearance beauty of the tire is improved; on the other hand, for the outer shoulder tread portion 202, it needs to bear greater pressure during the tire turning process and is prone to uneven wear. Therefore, the first sub-connecting groove 121 with a smaller depth and arranged at an angle with the third sub-connecting groove 123 is used to ensure that the end of the outer shoulder tread portion 202 closer to the central plane S of the tire has greater rigidity while achieving connection, so as to improve the anti-uneven wear performance of the tire and extend the service life of the tire.
[0046] As Figures 1 to 9As shown, the tire tread structure further includes a first strip-shaped chamfer 13, and the first strip-shaped chamfer 13 is disposed on the inner wall of the connecting groove 12; and / or, on the inner wall of the strip-shaped recess 11; and / or, on the inner wall of the second recess 7. The first strip-shaped chamfer 13 includes a first sub-strip-shaped chamfer 131 and a second sub-strip-shaped chamfer 132 that are interconnected. The second sub-strip-shaped chamfer 132 is disposed closer to the central plane S than the first sub-strip-shaped chamfer 131. Wherein, along the direction from the central plane S to the shoulder tread portion 2, the width of the second sub-strip-shaped chamfer 132 gradually increases, the depth of the second sub-strip-shaped chamfer 132 gradually increases, the width of the first sub-strip-shaped chamfer 131 gradually decreases, and the depth of the first sub-strip-shaped chamfer 131 gradually decreases. The strip-shaped recess 11 on the inner shoulder tread portion 201 is the inner strip-shaped recess 11, and the strip-shaped recess 11 on the outer shoulder tread portion 202 is the outer strip-shaped recess 11. The first strip-shaped chamfer 13 is disposed on the inner wall of the inner strip-shaped recess 11, and the second strip-shaped chamfer 15 is disposed on the inner wall of the outer strip-shaped recess 11. The second strip-shaped chamfer 15 surrounds the outer strip-shaped recess 11 and is located at one end of the outer strip-shaped recess 11 close to the central plane S.
[0047] Specifically, the strip-shaped chamfer is actually a chamfer (bevel) at the inner wall edge of the connecting groove 12, the strip-shaped recess 11, and the second recess 7.
[0048] In this embodiment, the tire tread structure in this embodiment actually adopts a multi-chamfer setting, and each chamfer is a gradually changing chamfer. The multi-chamfer design can, on the one hand, avoid the phenomenon of "chunk falling" of the tread caused by the relatively sharp edge being squeezed and stuck into the road surface gap during the rolling of the tire, thereby extending the service life of the tire; on the other hand, when the tread is squeezed and deformed, the cutting surface of the chamfer can come into contact with the driving surface, that is, the instantaneous contact area is increased, further improving the grip of the tire. The design of the gradually changing chamfer makes the above changes be gradually changing, which is beneficial to improving the bite reliability between the tread portion and the driving surface, and further improving the grip of the tire.
[0049] In this embodiment, a third groove 14 is further disposed on the inner shoulder tread portion 201. The third groove 14 is located between the inner strip-shaped recess 11 and the longitudinal groove 1. The inner strip-shaped recess 11 is connected to the longitudinal groove 1 through the third groove 14. The width W5 of the third groove 14 satisfies: 0.4m ≤ W5 ≤ 0.8mm. In this way, the third groove 14 can also play a role in cutting the water film to further improve the anti-wetting performance of the tire.
[0050] Optionally, the tire tread structure includes a plurality of tread pattern groups 16 arranged circumferentially along the tire. The pitch P1 of the first tread pattern group, the pitch P2 of the second tread pattern group, the pitch P3 of the third tread pattern group, the pitch P4 of the fourth tread pattern group, and the pitch P2 of the fifth tread pattern group among the plurality of tread pattern groups 16 satisfy: 1.14P1 ≤ P2 ≤ 1.146P1, 1.284P1 ≤ P3 ≤ 1.3P1, 1.4P1 ≤ P4 ≤ 1.46P1, 1.57P1 ≤ P5 ≤ 1.6P1; and / or, the contact surface between the tire and the driving surface has a width TAW. Along the direction from the inner side to the outer side of the tire, the plurality of longitudinal grooves 1 include a first longitudinal groove 101, a second longitudinal groove 102, a third longitudinal groove 103, and a fourth longitudinal groove 104. The width w1 of the first longitudinal groove 101, the width w2 of the second longitudinal groove 102, the width w3 of the third longitudinal groove 103, the width w4 of the fourth longitudinal groove 104, and the width TAW satisfy: 0.061TAW ≤ w1 ≤ 0.067TAW, 0.071TAW ≤ w2 ≤ 0.077TAW, 0.075TAW ≤ w3 ≤ 0.081TAW, 0.045TAW ≤ w4 ≤ 0.051TAW. The width W6 of the inner shoulder tread portion 201, the width W2 of the inner crown tread portion 6, the width W1 of the central tread portion 5, the width W3 of the outer crown tread portion 8, the width W7 of the outer shoulder tread portion 202, and the width TAW satisfy: 0.174TAW ≤ W6 ≤ 0.204TAW, 0.113TAW ≤ W2 ≤ 0.133TAW, 0.113TAW ≤ W1 ≤ 0.144TAW, 0.105TAW ≤ W3 ≤ 0.165TAW, 0.157TAW ≤ W7 ≤ 0.187TAW. In this way, on the one hand, the above settings make the pattern arrangement of the tire tread structure more complex through the five-pitch setting, so as to effectively suppress the noise generated by the tire tread structure in contact with the ground, thereby reducing the driving noise of the vehicle; on the other hand, the above size limitations actually make the entire tire tread structure an asymmetric pattern design, that is, the width of the longitudinal grooves 1 near the outer side of the tire is smaller, and the widths of the outer shoulder tread portion 202 and the outer crown tread portion 8 near the outer side of the tire are larger, and the rigidity is greater than that of the longitudinal grooves 1 near the inner side of the tire, the inner shoulder tread portion 201, and the inner crown tread portion 6. When the tire turns, the friction force between the tire and the driving surface can be effectively increased, making the vehicle have stronger grip and higher safety performance. While the width of the longitudinal grooves 1 near the inner side of the tire is larger, and the widths of the longitudinal grooves 1 near the inner side of the tire, the inner shoulder tread portion 201, and the inner crown tread portion 6 are smaller, which can effectively improve the drainage performance of the tire.
[0051] As Figures 3 to 5As shown in the figure, chamfers are provided at the joints between the groove walls and the groove bottoms of the four longitudinal grooves 1 in this embodiment, and chamfers are also provided between the groove walls and the outer surface of the tire tread, so as to improve the anti-wear ability of each tread portion and reduce the risk of groove stone trapping. Specifically, a third angle A3 is provided between one groove wall of the first longitudinal groove 101 and its normal line, and a fourth angle A4 is provided between the other groove wall of the first longitudinal groove 101 and its normal line. The third angle A3 is 10°, and the fourth angle A4 is 12°. The second longitudinal groove 102 and the third longitudinal groove 103 both adopt a symmetric design, and a fifth angle A5 is provided between their groove walls and the normal line. The fifth angle A5 is 10°. A sixth angle A6 is provided between one groove wall of the fourth longitudinal groove 104 and the normal line, and a seventh angle A7 is provided between the other groove wall of the fourth longitudinal groove 104 and the normal line. The sixth angle A6 is 8°, and the seventh angle A7 is 10°.
[0052] As Figure 6 shown in the figure, the first recess 3 in this embodiment adopts a symmetric design, its bottom wall is an arc surface, and an eighth angle A8 is provided between the inner wall of the first recess 3 and its normal line. The eighth angle A8 is 10°.
[0053] As Figure 7 shown in the figure, the strip-shaped recess 11 provided on the inner shoulder tread portion 201 in this embodiment adopts a symmetric setting. A chamfer is provided at the joint between its inner wall and the bottom wall, and a cut angle is provided at the joint between its inner wall and the outer surface of the tire tread structure. A ninth angle A9 is provided between its inner wall and its normal line. The ninth angle A9 is 3°.
[0054] As Figure 8 shown in the figure, the communicating groove 12 provided on the inner shoulder tread portion 201 in this embodiment adopts a symmetric setting. A chamfer is provided at the joint between its groove wall and the groove bottom, and a tenth angle A10 is provided between its groove wall and the normal line. The tenth angle A10 is 3°.
[0055] In this embodiment, the maximum depth of the first strip-shaped cut angle 13 on the inner wall of the communicating groove 12 provided on the inner shoulder tread portion 201 is 3 mm, that is, the depth gradually changes from 0 mm to 3 mm, and then gradually changes to 0 mm.
[0056] As Figure 9 shown in the figure, the communicating groove 12 provided on the outer shoulder tread portion 202 in this embodiment adopts a symmetric setting. A chamfer is provided at the joint between its groove wall and the groove bottom, and an eleventh angle A11 is provided between its groove wall and the normal line. The eleventh angle A11 is 3°.
[0057] As Figure 10As shown, in this embodiment, the strip-shaped recesses 11 on the outer shoulder tread portion 202 are symmetrically arranged. A chamfer is provided at the connection between the inner wall and the bottom wall. The inner wall is arranged at a twelfth included angle A12 with the normal line, and the twelfth included angle A12 is 3°.
[0058] Specifically, the designs of the chamfer and the cut angle are both to reduce the risk of stone trapping in the groove or recess and reduce the possibility of "chunk shedding" in the tread portion, which will not be elaborated again.
[0059] This application also provides a tire (not shown), and the tire has the above-mentioned tire tread structure.
[0060] From the above description, it can be seen that the above embodiments of the present utility model achieve the following technical effects:
[0061] A plurality of longitudinal grooves of the tire tread structure extend along the circumferential direction of the tire. The plurality of longitudinal grooves are spaced apart in the width direction of the tire, dividing the tread into two shoulder tread portions and an intermediate tread portion located between the two shoulder tread portions. A first recess is provided on the intermediate tread portion. One end of the first recess extends to one side of the intermediate tread portion to communicate with the longitudinal groove, and there is a preset distance between the other end of the first recess and the other side of the intermediate tread portion; a first groove is provided on the intermediate tread portion. Among them, the first groove has a first sub-groove and a second sub-groove that communicate with each other. The first sub-groove is located on the bottom wall of the first recess, and the second sub-groove is located outside the first recess. The end of the first sub-groove away from the second sub-groove communicates with the longitudinal groove. First of all, the setting of the plurality of longitudinal grooves can play a role in draining and guiding water when the tire is running on a wet road surface (that is, the water between the tread and the running surface can be squeezed into the longitudinal grooves), so as to avoid too much water between the tire tread and the running surface, resulting in a decrease in the friction coefficient between the tire and the running surface, and initially improving the grip performance of the tire; Secondly, the first recess provided on the core contact area (intermediate tread portion) between the tread and the running surface can play a role in balancing rigidity and promoting the deformation of the intermediate tread portion, so that the intermediate tread portion can better bite with the running surface, further improving the grip performance of the tire, and the first sub-groove located on the bottom wall of the first recess can balance the rigidity at the first recess from the root of the intermediate tread portion and at a deeper level, further improving the biting reliability of the intermediate tread portion. At the same time, the second sub-groove and the edge of the first recess can actually play a role in cutting the water film (during the rolling process of the tire, the second sub-groove and the edge of the first recess will be squeezed to "cut" the water film between the tread and the running surface), so as to avoid the formation of a complete water film and further improve the grip performance of the tire on a wet road surface. It can be seen that the tire adopting the tire tread structure in the present application has good grip performance both on dry roads and wet roads, greatly meets the higher tire grip requirements of new energy vehicles, and further solves the problem that the tire tread structure in the prior art cannot meet the grip requirements of new energy vehicles, reduces the braking distance when the vehicle brakes, and ensures the personal safety of the passengers and drivers.
[0062] Obviously, the above-described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.
[0063] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular forms are also intended to include the plural forms. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they specify the presence of features, steps, operations, devices, components, and / or combinations thereof.
[0064] It should be noted that the terms "first", "second", etc. in the description and claims of the present application and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged under appropriate circumstances so that the embodiments of the present application described herein can be implemented in an order different from those illustrated or described herein.
[0065] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.
Claims
1. A tire tread structure, characterized in that, Comprising: A plurality of longitudinal grooves (1), each of the longitudinal grooves (1) extending along the circumferential direction of the tire, and the plurality of longitudinal grooves (1) being spaced apart along the width direction of the tire, so that the tread is divided into two shoulder tread portions (2) and an intermediate tread portion located between the two shoulder tread portions (2); A first recess (3), provided on the intermediate tread portion, one end of the first recess (3) extending to one side of the intermediate tread portion to communicate with the longitudinal groove (1), and there being a preset distance between the other end of the first recess (3) and the other side of the intermediate tread portion; A first groove (4), provided on the intermediate tread portion; Wherein, the first groove (4) has a first sub-groove (401) and a second sub-groove (402) that communicate with each other, the first sub-groove (401) being located on the bottom wall of the first recess (3), the second sub-groove (402) being located outside the first recess (3), and the end of the first sub-groove (401) away from the second sub-groove (402) communicating with the longitudinal groove (1).
2. The tire tread structure according to claim 1, characterized in that, The end of the first recess (3) that communicates with the longitudinal groove (1) is a communication end, and along the direction from the communication end to the other end of the first recess (3), the width of the first recess (3) gradually decreases.
3. The tire tread structure according to claim 2, characterized in that, The plurality of intermediate tread portions include: A center tread portion (5), at least a part of the center tread portion (5) coinciding with the center plane S of the tire, and the center tread portion (5) having a width W1; An inner crown tread portion (6), located between the center tread portion (5) and the shoulder tread portion (2), the inner crown tread portion (6) being disposed relatively closer to the inner side of the tire than the center tread portion (5), and the inner crown tread portion (6) having a width W2; Wherein, the first recess (3) is provided on both the center tread portion (5) and the inner crown tread portion (6), the first recess (3) on the center tread portion (5) being a center recess, and the first recess (3) on the inner crown tread portion (6) being an inner recess. The lengths L1 of the center recess and L2 of the inner recess satisfy: 0.25W1 ≤ L2 ≤ 0.5W1, 0.5W2 ≤ L2 ≤ 0.75W2, and L1 < L2; the extending direction of the inner recess forms a first included angle A1 with the width direction of the tire, and the first included angle A1 satisfies: 8° ≤ A1 ≤ 20°.
4. The tire tread structure according to claim 3, characterized in that, The tire tread structure further includes: A second recess (7), provided on the inner crown tread portion (6), one end of the second recess (7) extending to one side of the inner crown tread portion (6) to communicate with the longitudinal groove (1), and there being a preset distance between the other end of the second recess (7) and the other side of the inner crown tread portion (6); Among them, the first concave part (3) and the second concave part (7) are respectively communicated with two longitudinal grooves (1) adjacent to the inner crown pattern part (6). The extending direction of the second concave part (7) forms a second included angle A2 with the width direction of the tire, and the second included angle A2 satisfies: 19° ≤ A2 ≤ 25°. The length L3 of the second concave part (7) and the width W2 satisfy: 0.6W2 ≤ L3 ≤ 0.8W2.
5. The tire tread structure according to claim 4, characterized in that, The tire tread structure further includes: An outer crown pattern part (8), the outer crown pattern part (8) is arranged closer to the outer side of the tire relative to the central pattern part (5), and the outer crown pattern part (8) has a width W3; A third concave part (9) is arranged on the outer crown pattern part (8). One end of the third concave part (9) extends to one side surface of the outer crown pattern part (8) to be communicated with the longitudinal groove (1), and there is a preset distance between the other end of the third concave part (9) and the other side surface of the outer crown pattern part (8); among them, there are a plurality of the third concave parts (9), and the plurality of the third concave parts (9) are arranged at intervals in the circumferential direction of the tire to divide the outer crown pattern part (8) into a plurality of outer crown pattern blocks; A second groove (10) is arranged on the outer crown pattern block. One end of the second groove (10) is communicated with a longitudinal groove (1) adjacent to the outer crown pattern part (8), and there is a preset distance between the other end of the second groove (10) and another longitudinal groove (1) adjacent to the outer crown pattern part (8); Among them, the length L4 of the second groove (10) and the width W3 satisfy: 0.25W3 ≤ L4 ≤ 0.5W3, and the width W4 of the second groove (10) satisfies: 0.4 mm ≤ W4 ≤ 0.8 mm.
6. The tire tread structure according to claim 5, wherein, The tire tread structure further includes: A strip-shaped concave part (11) is arranged on the shoulder pattern part (2). There is a preset distance between the end of the strip-shaped concave part (11) and the side surface of the shoulder pattern part (2). There are a plurality of the strip-shaped concave parts (11), and the plurality of the strip-shaped concave parts (11) are arranged at intervals in the circumferential direction of the tire to divide the shoulder pattern part (2) into a plurality of shoulder pattern blocks; A communication groove (12) is arranged on the shoulder pattern block, and the longitudinal groove (1) adjacent to the shoulder pattern part (2) is communicated with the shoulder of the tire through the communication groove (12).
7. The tire tread structure according to claim 6, characterized in that, The two shoulder pattern parts (2) include: An inner shoulder pattern part (201) arranged closer to the inner side of the tire relative to the central plane S, and the communication groove (12) arranged on the inner shoulder pattern part (201) is a straight groove; An outer shoulder tread portion (202) disposed closer to the outer side of the tire relative to the central plane S. The connecting groove (12) provided on the outer shoulder tread portion (202) includes a first sub-connecting groove (121), a second sub-connecting groove (122), and a third sub-connecting groove (123) that are connected in sequence. One end of the first sub-connecting groove (121) far from the second sub-connecting groove (122) is connected to a longitudinal groove (1) adjacent to the outer shoulder tread portion (202), and one end of the third sub-connecting groove (123) far from the second sub-connecting groove (122) is connected to the shoulder of the tire; Wherein, along the direction from the third sub-connecting groove (123) to the first sub-connecting groove (121), the width of the second sub-connecting groove (122) gradually decreases. The extending direction of the first sub-connecting groove (121) and the extending direction of the third sub-connecting groove (123) are arranged at an angle, and the depth of the first sub-connecting groove (121) is less than the depth of the second sub-connecting groove (122).
8. The tire tread structure according to claim 7, characterized in that, The tire tread structure further includes: A first strip-shaped chamfer (13) provided on the inner wall of the connecting groove (12); and / or, on the inner wall of the strip-shaped recess (11); and / or, on the inner wall of the second recess (7). The first strip-shaped chamfer (13) includes a first sub-strip-shaped chamfer (131) and a second sub-strip-shaped chamfer (132) that are connected to each other. The second sub-strip-shaped chamfer (132) is disposed closer to the central plane S relative to the first sub-strip-shaped chamfer (131); Wherein, along the direction from the central plane S to the shoulder tread portion (2), the width of the second sub-strip-shaped chamfer (132) gradually increases, the depth of the second sub-strip-shaped chamfer (132) gradually increases, the width of the first sub-strip-shaped chamfer (131) gradually decreases, and the depth of the first sub-strip-shaped chamfer (131) gradually decreases.
9. The tire tread structure according to claim 8, characterized in that, The strip-shaped recess (11) located on the inner shoulder tread portion (201) is an inner strip-shaped recess (11), and the strip-shaped recess (11) located on the outer shoulder tread portion (202) is an outer strip-shaped recess (11). The first strip-shaped chamfer (13) is provided on the inner wall of the inner strip-shaped recess (11); A third groove (14) is further provided on the inner shoulder tread portion (201). The third groove (14) is located between the inner strip-shaped recess (11) and the longitudinal groove (1). The inner strip-shaped recess (11) is connected to the longitudinal groove (1) through the third groove (14). The width W5 of the third groove (14) satisfies: 0.4 mm ≤ W5 ≤ 0.8 mm; A second strip-shaped chamfer (15) is provided on the inner wall of the outer strip-shaped recess (11). The second strip-shaped chamfer (15) surrounds the outer strip-shaped recess (11) and is located at one end of the outer strip-shaped recess (11) closer to the central plane S.
10. The tire tread structure according to claim 7, wherein The tire tread structure includes a plurality of tread pattern groups (16) arranged circumferentially along the tire, and the pitches P1 of the first tread pattern group, P2 of the second tread pattern group, P3 of the third tread pattern group, P4 of the fourth tread pattern group, and P5 of the fifth tread pattern group among the plurality of tread pattern groups (16) satisfy: 1.14P1 ≤ P2 ≤ 1.146P1, 1.284P1 ≤ P3 ≤ 1.3P1, 1.4P1 ≤ P4 ≤ 1.46P1, 1.57P1 ≤ P5 ≤ 1.6P1; and / or, The contact surface between the tire and the running surface has a width TAW. In the direction from the inner side to the outer side of the tire, the plurality of longitudinal grooves (1) include a first longitudinal groove (101), a second longitudinal groove (102), a third longitudinal groove (103), and a fourth longitudinal groove (104). The width w1 of the first longitudinal groove (101), the width w2 of the second longitudinal groove (102), the width w3 of the third longitudinal groove (103), the width w4 of the fourth longitudinal groove (104), and the width TAW satisfy: 0.061TAW ≤ w1 ≤ 0.067TAW, 0.071TAW ≤ w2 ≤ 0.077TAW, 0.075TAW ≤ w3 ≤ 0.081TAW, 0.045TAW ≤ w4 ≤ 0.051TAW; The width W6 of the inner shoulder tread portion (201), the width W2 of the inner crown tread portion (6), the width W1 of the center tread portion (5), the width W3 of the outer crown tread portion (8), the width W7 of the outer shoulder tread portion (202), and the width TAW satisfy: 0.174TAW ≤ W6 ≤ 0.204TAW, 0.113TAW ≤ W2 ≤ 0.133TAW, 0.113TAW ≤ W1 ≤ 0.144TAW, 0.105TAW ≤ W3 ≤ 0.165TAW, 0.157TAW ≤ W7 ≤ 0.187TAW.