Automobile tire used in summer
By combining steel sheets with longitudinal grooves and asymmetrical distribution, the problem of insufficient rigidity of tire tread blocks in summer is solved, improving the grip and load-bearing capacity of new energy vehicles, reducing noise, and extending service life.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-19
- Publication Date
- 2026-04-10
AI Technical Summary
Existing summer car tires in new cars have insufficient tread block rigidity, which cannot adapt to high instantaneous torque, resulting in insufficient grip and poor load-bearing performance. After long-term use, they are prone to uneven wear, affecting handling stability.
The design combines steel sheets with longitudinal grooves to enhance the rigidity of the patterned blocks. Combined with the asymmetrical distribution of longitudinal grooves and the multi-layered variable pitch arrangement, it optimizes drainage performance and noise control, meeting the high requirements of new energy vehicles.
It improves grip on dry and wet surfaces, reduces the risk of slipping, optimizes load-bearing performance, reduces noise, extends service life, and is suitable for the high quietness and range requirements of new energy vehicles.
Smart Images
Figure CN121821998A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of automobile tires, in particular to a summer automobile tire. BACKGROUND
[0002] With the popularity of automobiles, higher requirements are placed on the performance of tires. Compared with traditional fuel vehicles, emerging vehicles have different torque output characteristics, with large instantaneous torque, which requires the tire to have better grip to prevent skidding. Moreover, emerging vehicles have a large self-weight, and the added battery increases the vehicle weight, which tests the load-carrying capacity of the tire. Furthermore, in order to improve the range, the rolling resistance of the tire must be reduced to reduce energy loss.
[0003] Summer automobile tires are key components in the automobile driving system, mainly adapting to the driving needs of emerging vehicles and new energy vehicles, and the core needs to meet various use requirements such as dry and wet grip, load-carrying performance, drainage effect, and driving quietness, which are important links to ensure vehicle driving safety and driving experience.
[0004] Although the existing summer automobile tires have a cooperating structure of steel sheets and longitudinal grooves, the adaptability of the two is poor, which makes it difficult to balance the pattern rigidity, resulting in insufficient ground contact area during dry driving, affecting the wear performance, and the tire cannot efficiently break the water film on the road surface in wet conditions, which is prone to skidding, and it is difficult to match the high requirements of emerging vehicles on grip. The pattern blocks at the shoulder of the tire body also use a horizontal groove division design, and some products also have steel sheets in the horizontal groove, which results in insufficient rigidity of the pattern blocks, which cannot adapt to the characteristics of large instantaneous torque of new energy vehicles, not only has insufficient instantaneous grip, but also has poor load-carrying performance, and is prone to eccentric wear after long-term use, affecting the vehicle control stability. SUMMARY
[0005] In view of the deficiencies of the prior art, the present application provides a summer automobile tire to solve the technical problems of insufficient rigidity of the pattern blocks, which cannot adapt to the characteristics of large instantaneous torque of new energy vehicles, not only has insufficient instantaneous grip, but also has poor load-carrying performance, and is prone to eccentric wear after long-term use, affecting the vehicle control stability.
[0006] To achieve the above purpose, the present application provides the following technical solution: a summer automobile tire, comprising: a tire body and longitudinal grooves A, B, C and D arranged in sequence on the outer surface of the tire body.
[0007] The inner cavities of the longitudinal grooves A are uniformly provided with first steel sheets, the inner cavities of the longitudinal grooves B are uniformly provided with second steel sheets, the inner cavities of the longitudinal grooves C are uniformly provided with third steel sheets, and the inner cavities of the longitudinal grooves D are uniformly provided with fourth steel sheets. The first steel sheets, the second steel sheets, the third steel sheets and the fourth steel sheets are combined with the longitudinal grooves A, the longitudinal grooves B, the longitudinal grooves C and the longitudinal grooves D to respectively cut the top of the carcass into first pattern blocks, second pattern blocks, third pattern blocks and fourth pattern blocks. The first steel sheets, the second steel sheets, the third steel sheets and the fourth steel sheets are distributed along the circumference of the carcass, and the circumferential surfaces of the four groups of pattern blocks are all distributed with steel sheets, which are used to balance the pattern rigidity and break the water film to improve the grip.
[0008] The tire ground contact area can be increased during dry driving to improve wear performance, and the water film on the road surface can be quickly broken under wet conditions to avoid tire skidding, which meets the high requirements of emerging vehicles on grip. The pattern blocks at the shoulder of the carcass are divided by transverse grooves, and no steel sheets are arranged in the transverse grooves to enhance the rigidity of the pattern blocks. The characteristics of large instantaneous torque of new energy vehicles can be targeted to improve instantaneous grip, while the tire load bearing performance is optimized to reduce the problem of eccentric wear after long-term use and ensure the stability of control. The central part of the crown is a continuous pattern block, and the longitudinal grooves A, the longitudinal grooves B, the longitudinal grooves C and the longitudinal grooves D are asymmetrically distributed to balance the drainage performance of the inner and outer sides of the tire.
[0009] The risk of tire side slip and drift can be effectively reduced during high-speed driving to provide stable traction for the vehicle, which meets the characteristics of the changing distribution of the center of gravity of emerging vehicles. The tire circumference adopts a multi-level variable pitch arrangement to reduce the noise generated during tire driving. The performance is optimized through computer simulation, which can effectively reduce the impact noise of the pattern blocks, the groove pumping noise and the air column resonance noise to improve the driving quietness and adapt to the high quietness use scenarios of emerging vehicles. The longitudinal grooves A, the longitudinal grooves B, the longitudinal grooves C and the longitudinal grooves D are respectively matched with the corresponding steel sheets.
[0010] Preferably, the carcass comprises a cushion layer, and the outer layer of the cushion layer is sequentially provided with a cord layer, an inner surface layer, a reinforcing layer and a wear-resistant layer. The outer part of the wear-resistant layer is provided with a triangular rubber, and the outer part of the triangular rubber is provided with a lip part. The layers cooperate to absorb road impact, the cord layer and the reinforcing layer enhance the overall support strength of the carcass, the wear-resistant layer improves the durability of use, the triangular rubber and the lip part optimize the stability of the tire bead, and the overall adaptation to the characteristics of the relatively large weight of emerging vehicles improves the tire load capacity and structural reliability.
[0011] Preferably, the steel sheets on the circumferential surfaces of the first pattern block, the second pattern block, the third pattern block and the fourth pattern block are uniformly arranged along the radial direction of the tire. Further optimize the rigidity balance effect of the pattern block, avoid uneven stress in local area, improve the overall wear uniformity of the tire, prolong the service life, and at the same time ensure that the water film breaking effect of the steel sheet covers the entire surface of the pattern block, and comprehensively improves the grip.
[0012] Preferably, the longitudinal extension direction of the pattern block at the shoulder part of the tire body is consistent with the circumferential direction of the tire, and the transverse grooves between the pattern blocks are arranged along the radial direction of the tire. This direction design can strengthen the longitudinal rigidity transmission of the pattern block, ensure the stability of the instantaneous grip, and at the same time, the radial transverse groove can quickly guide the accumulated water to flow out, cooperate with the structure design without steel sheet, improve the rigidity while not affecting the drainage efficiency, and adapt to the driving demand in complex road conditions.
[0013] Preferably, the outer surface of the continuous pattern block at the center of the crown is at the same level as the outer surface of the pattern block outside the tire body tread. Ensure uniform contact with the ground when the tire is running, avoid partial stress concentration leading to eccentric wear or performance degradation, and at the same time, strengthen the longitudinal support of the tread, further reduce the rolling resistance, help emerging vehicles improve endurance performance, and improve driving smoothness.
[0014] Preferably, the groove width of the longitudinal groove A is the same as that of the longitudinal groove D, the groove width of the longitudinal groove B is the same as that of the longitudinal groove C, and the groove width of the longitudinal groove A and the longitudinal groove D is greater than that of the longitudinal groove B and the longitudinal groove C. The groove width difference design cooperates with the asymmetric distribution to optimize the drainage flow rate and path of the inner and outer sides of the tire. The wide groove on the outer side quickly drains a large amount of accumulated water, and the narrow groove on the inner side refines the water film removal effect. Double protection of the grip stability when driving in wet land reduces the risk of water sliding.
[0015] Preferably, in the multi-level variable pitch arrangement, the pitch arrangement density of the shoulder part is greater than that of the middle pattern block part. Further optimize the balance effect of noise control and grip, the high-density pitch at the shoulder can weaken the noise generated by the vibration of the shoulder, and the reasonable pitch in the middle part can ensure the rigidity and contact area of the pattern block, so that the driving experience is more comfortable, and at the same time, it meets the quietness demand of emerging vehicles.
[0016] Preferably, the buffer layer is made of elastic rubber material, and the buffer layer and the cord layer are fixedly connected through vulcanization process. The buffer layer made of elastic rubber material can effectively absorb the impact of road bumps and reduce the vibration conduction to the vehicle interior. The vulcanization process ensures that the layers are tightly and firmly connected, avoids the separation between the layers under long-term high pressure, and improves the overall structure and durability of the tire.
[0017] Preferably, the steel sheet of the circumferential surface of the pattern block is arranged in an inclined manner, the inclination direction is matched with the rolling direction of the tire, the continuous pattern blocks in the central part of the crown are continuously distributed along the tire circumferential direction, and the width of the continuous pattern blocks covers the middle part of the tire in the transverse direction. The design of the continuous pattern blocks can improve the longitudinal support of the tire, reduce the rolling resistance, reduce the energy loss of the vehicle, and help the emerging vehicles to extend the cruising range; the inclined arrangement of the steel sheet matched with the rolling direction can enhance the guidance of the film breaking of the steel sheet and improve the response speed of the wet grip.
[0018] The inner side surface of the triangular rubber is matched with the outer side surface of the wear-resistant layer, and the thickness of the triangular rubber gradually decreases from the side close to the lip part to the side away from the lip part. The close match of the triangular rubber and the wear-resistant layer can enhance the connection strength of the tire side and the bead, the thickness gradient design optimizes the lateral support force of the tire body, provides stable support when the vehicle turns or leans, and guarantees the safety of the steering, while adapting to the stress characteristics after the layout change of the chassis of the emerging vehicles.
[0019] Compared with the prior art, the present application provides a summer automobile tire, which has the following beneficial effects:
[0020] The summer automobile tire can balance the pattern rigidity and effectively break the water film through the cooperation of the steel sheet and the longitudinal groove, can increase the ground contact area to improve the wear performance when driving on dry ground, and can quickly break the water film on the road surface to avoid slipping under wet conditions, fully meeting the high requirements of emerging vehicles for grip. The pattern blocks at the shoulder part of the tire body are divided by transverse grooves, and there is no steel sheet arranged in the transverse grooves, which effectively enhances the rigidity of the pattern blocks, can be adapted to the characteristics of large instantaneous torque of new energy vehicles, improves the instantaneous grip, optimizes the load bearing performance of the tire, reduces the eccentric wear problem after long-term use, and guarantees the stability of the vehicle control. The continuous pattern blocks in the central part of the crown are matched with the asymmetrically distributed longitudinal grooves, which can balance the drainage performance of the inner and outer sides of the tire, can effectively reduce the risk of side slip and drift when driving at high speed, and can provide stable traction for the vehicle, adapting to the characteristics of the change of the gravity distribution of emerging vehicles. The multi-level variable pitch arrangement of the tire tread circumferential direction, combined with the performance optimization of computer simulation, can effectively reduce the impact noise of the pattern blocks, the groove pumping noise and the air column resonance noise, improve the driving quietness, and adapt to the high use demand of emerging vehicles for quietness. BRIEF DESCRIPTION OF DRAWINGS
[0021] Figure 1 It is a front view of the present application;
[0022] Figure 2 It is a left side view of the present application;
[0023] Figure 3 It is a schematic view of the inner part of the tire body of the present application;
[0024] Figure 4 It is a pattern view of the tire body of the present application;
[0025] Figure 5 Figure for explaining the pitch arrangement of the carcass of the present application.
[0026] In the figure: 1, first steel sheet; 11, first pattern block; 12, second pattern block; 13, third pattern block; 14, fourth pattern block; 2, second steel sheet; 3, third steel sheet; 4, fourth steel sheet; 5, carcass; 51, cushion layer; 52, cord layer; 53, inner surface layer; 54, reinforcing layer; 6, triangular rubber; 61, tire lip part. DETAILED DESCRIPTION
[0027] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.
[0028] The present application provides a technical solution, please refer to Figures 1-4 A car tire for summer, comprising: a carcass 5 and a longitudinal groove A, a longitudinal groove B, a longitudinal groove C and a longitudinal groove D arranged in sequence on the outer surface of the carcass 5.
[0029] The inner cavity of the longitudinal groove A is uniformly provided with a first steel sheet 1, the inner cavity of the longitudinal groove B is uniformly provided with a second steel sheet 2, the inner cavity of the longitudinal groove C is uniformly provided with a third steel sheet 3, and the inner cavity of the longitudinal groove D is uniformly provided with a fourth steel sheet 4. The first steel sheet 1, the second steel sheet 2, the third steel sheet 3 and the fourth steel sheet 4 are combined with the longitudinal groove A, the longitudinal groove B, the longitudinal groove C and the longitudinal groove D, respectively cutting the top of the carcass 5 into a first pattern block 11, a second pattern block 12, a third pattern block 13 and a fourth pattern block 14. The first steel sheet 1, the second steel sheet 2, the third steel sheet 3 and the fourth steel sheet 4 are distributed along the circumference of the carcass 5, and the circumferential surface of the four groups of pattern blocks is distributed with steel sheets, which are used to balance the pattern rigidity, break the water film to improve the grip;
[0030] When driving on dry land, the tire ground contact area can be increased to improve the wear performance, and under wet road conditions, the water film on the road surface can be quickly broken to avoid tire slip, which is suitable for the high requirements of emerging cars on grip. The pattern blocks at the shoulder part of the carcass 5 are divided by transverse grooves, and there is no steel sheet arranged in the transverse grooves to enhance the rigidity of the pattern blocks. It can be targeted to cope with the characteristics of large instantaneous torque of new energy vehicles, improve the instantaneous grip, optimize the load bearing performance of the tire, reduce the problem of eccentric wear after long-term use, and ensure the stability of operation and control. The central part of the crown is a continuous pattern block, and the longitudinal groove A, the longitudinal groove B, the longitudinal groove C and the longitudinal groove D are asymmetrically distributed to balance the drainage performance inside and outside the tire.
[0031] The tire can effectively reduce the risk of tire side slip and drift during high-speed driving, provide stable traction for the vehicle, adapt to the characteristics of the changing distribution of the center of gravity of emerging vehicles, and the circumferential tread adopts a multi-level variable-pitch arrangement to reduce noise generated during tire driving. The performance is optimized through computer simulation, which can effectively reduce the impact noise of the pattern block, groove pumping noise and air column resonance noise, improve the driving quietness, and adapt to the high quietness use scenario of emerging vehicles. The longitudinal groove A, the longitudinal groove B, the longitudinal groove C and the longitudinal groove D are respectively matched with the corresponding steel sheet.
[0032] The carcass 5 includes a cushion layer 51, and the outer layer of the cushion layer 51 is sequentially provided with a cord layer 52, an inner surface layer 53, a reinforcing layer 54 and a wear-resistant layer 55. The outer part of the wear-resistant layer 55 is provided with a triangular rubber 6, and the outer part of the triangular rubber 6 is provided with a tire lip part 61. The layers cooperate with each other, the cushion layer 51 can absorb the impact of the road, the cord layer 52 and the reinforcing layer 54 enhance the overall support strength of the carcass 5, the wear-resistant layer 55 improves the use durability, the triangular rubber 6 and the tire lip part 61 optimize the stability of the tire bead, and the whole adapts to the characteristics of the larger self-weight of the emerging vehicle, improves the tire carrying capacity and structural reliability.
[0033] The steel sheets on the circumferential surfaces of the first pattern block 11, the second pattern block 12, the third pattern block 13 and the fourth pattern block 14 are uniformly arranged along the radial direction of the tire. The rigidity balance effect of the pattern block is further optimized to avoid uneven local stress, improve the overall wear uniformity of the tire, prolong the service life, and at the same time ensure that the breaking effect of the steel sheet on the water film covers the entire surface of the pattern block, and comprehensively improves the grip.
[0034] The pattern blocks at the shoulder parts of the carcass 5 are longitudinally extended in the same direction as the tire circumferential direction, and the transverse grooves between the pattern blocks are arranged along the radial direction of the tire. The design of this direction can strengthen the longitudinal rigidity transmission of the pattern block, ensure the stability of the instantaneous grip, and at the same time, the radial transverse groove can quickly guide the accumulated water to drain, cooperate with the structure design without steel sheet, improve the rigidity while not affecting the drainage efficiency, and adapt to the driving demand in complex road conditions.
[0035] The outer surface of the continuous pattern block at the center of the crown is at the same level as the outer surface of the pattern block outside the tire tread of the carcass 5. It ensures uniform ground contact during tire driving, avoids partial stress concentration leading to partial wear or performance degradation, and at the same time strengthens the longitudinal support of the tread, further reduces the rolling resistance, helps emerging vehicles to improve the endurance performance, and improves the driving smoothness.
[0036] The groove width of the longitudinal groove A is the same as that of the longitudinal groove D, the groove width of the longitudinal groove B is the same as that of the longitudinal groove C, and the groove width of the longitudinal groove A and the longitudinal groove D is greater than that of the longitudinal groove B and the longitudinal groove C. The asymmetric distribution of the groove width difference can optimize the drainage flow rate and path of the inner and outer sides of the tire. The outer wide groove quickly drains a large amount of accumulated water, and the inner narrow groove refines the water film removal effect, thereby double-protecting the grip stability during wet road driving and reducing the risk of aquaplaning.
[0037] In the multi-level variable pitch arrangement, the pitch arrangement density of the shoulder part is greater than that of the middle part. Further optimizing the balance between noise control and grip, the high-density pitch of the shoulder can weaken the noise generated by the shoulder vibration, and the reasonable pitch in the middle part ensures the rigidity and ground contact area of the pattern block, so that the driving experience is more comfortable, and it also meets the quietness demand of emerging vehicles.
[0038] The buffer layer 51 is made of elastic rubber material, and the buffer layer 51 and the cord layer 52 are fixedly connected through vulcanization process. The buffer layer 51 made of elastic rubber material can effectively absorb the impact of road bumps and reduce vibration transmission to the vehicle interior. The vulcanization process ensures that the layers are tightly and firmly connected, avoiding interlayer separation under long-term high pressure, and improving the overall structure and durability of the tire.
[0039] The steel sheet on the circumferential surface of the carcass 5 is inclined, the inclination direction is adapted to the rolling direction of the tire, the continuous pattern blocks in the crown center are distributed continuously along the tire circumference, and the width of the continuous pattern blocks covers the middle region of the tire in the transverse direction. The design of the continuous pattern blocks can improve the longitudinal support of the tire, reduce the rolling resistance, and reduce the energy loss of the vehicle, helping emerging vehicles to extend the range; the inclined arrangement of the steel sheet is adapted to the rolling direction, which can enhance the guidance of the steel sheet film breaking and improve the response speed of the wet grip.
[0040] The inner surface of the apex rubber 6 is attached to the outer surface of the wear-resistant layer 55, and the thickness of the apex rubber 6 gradually decreases from the side close to the lip 61 to the side away from the lip 61. The close attachment of the apex rubber 6 and the wear-resistant layer 55 can enhance the connection strength of the tire side and the bead, and the thickness gradient design optimizes the lateral support of the carcass 5, providing stable support when the vehicle turns or leans, ensuring the safety of the steering, and adapting to the stress characteristics of the emerging vehicle chassis layout changes.
[0041] It is to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting; it is not intended to exclude myriad other embodiments of the present application that other inventors can develop based on the same general inventive concepts embodied by the described embodiments. That is, although the present application is described in terms of particular embodiments and illustrative figures, it should be apparent that the scope of the present application is not limited to these specific embodiments.
[0042] While the embodiments of the application have been shown and described herein, it will be understood by those skilled in the art that many changes, modifications, substitutions and alterations to these embodiments can be made without departing from the principles and spirits of the application, and it is intended that the scope of the application be limited solely by the scope of the appended claims and the equivalents thereof.
Claims
1. A tyre for summer use for vehicles, comprising: The tire body (5) and the longitudinal grooves A, B, C and D arranged in sequence on the outer surface of the tire body (5) are characterized in that: the inner cavity of the longitudinal groove A is uniformly provided with the first steel sheet (1), the inner cavity of the longitudinal groove B is uniformly provided with the second steel sheet (2), the inner cavity of the longitudinal groove C is uniformly provided with the third steel sheet (3), and the inner cavity of the longitudinal groove D is uniformly provided with the fourth steel sheet (4); the first steel sheet (1), the second steel sheet (2), the third steel sheet (3) and the fourth steel sheet (4) are combined with the longitudinal groove A, the longitudinal groove B, the longitudinal groove C and the longitudinal groove D, and respectively cut the top of the tire body (5) into the first pattern block (11), the second pattern block (12), the third pattern block (13) and the fourth pattern block (14). The first steel sheet (1), the second steel sheet (2), the third steel sheet (3) and the fourth steel sheet (4) are circumferentially distributed along the tire body (5), and the circumferential surface of the four groups of pattern blocks is distributed with steel sheets, which are used to balance the pattern rigidity and break the water film to improve the grip. The pattern blocks of the tire shoulder part of the tire body (5) are divided by a transverse groove, and no steel sheet is arranged in the transverse groove to enhance the rigidity of the pattern block; the central part of the crown is a continuous pattern block, and the longitudinal grooves A, B, C and D are asymmetrically distributed to balance the drainage performance inside and outside the tire; the circumferential surface of the tire body (5) adopts a multi-level variable pitch arrangement to reduce the noise generated during the driving of the tire; the longitudinal grooves A, B, C and D are respectively matched with the corresponding steel sheets.
2. A tyre for summer use for vehicles according to claim 1, characterized in that: The tire body (5) comprises a buffer layer (51), and the outer layer of the buffer layer (51) is sequentially provided with a cord layer (52), an inner surface layer (53), a reinforcing layer (54) and a wear-resistant layer (55); the outer part of the wear-resistant layer (55) is provided with a triangular rubber (6), and the outer part of the triangular rubber (6) is provided with a tire lip part (61).
3. A tyre for summer use for vehicles according to claim 1, characterized in that: The steel sheets on the circumferential surface of the first pattern block (11), the second pattern block (12), the third pattern block (13) and the fourth pattern block (14) are uniformly arranged along the radial direction of the tire.
4. A tyre for summer use for vehicles according to claim 1, characterized in that: The longitudinal extension direction of the pattern blocks of the tire shoulder part of the tire body (5) is consistent with the circumferential direction of the tire, and the transverse grooves between the pattern blocks are arranged along the radial direction of the tire.
5. A tyre for summer use for vehicles according to claim 1, characterized in that: The outer surface of the continuous pattern block in the central part of the crown is at the same level as the outer surface of the pattern block of the tire body (5) outside the tread.
6. A tyre for summer use for vehicles according to claim 1, characterized in that: The groove width of the longitudinal groove A and the longitudinal groove D is the same, the groove width of the longitudinal groove B and the longitudinal groove C is the same, and the groove width of the longitudinal groove A and the longitudinal groove D is greater than the groove width of the longitudinal groove B and the longitudinal groove C.
7. A tyre for summer use for vehicles according to claim 1, characterized in that: In the multi-level variable pitch arrangement, the pitch arrangement density of the shoulder part is greater than the pitch arrangement density of the central pattern block part.
8. A tyre for summer use for vehicles according to claim 2, characterized in that: The buffer layer (51) is made of elastic rubber material, and the buffer layer (51) and the cord layer (52) are fixedly connected through a vulcanization process.
9. A tyre for summer use for vehicles according to claim 1, characterized in that: The steel sheets on the circumferential surface of the pattern blocks of the tire body (5) are arranged obliquely, the oblique direction is matched with the rolling direction of the tire, the continuous pattern block in the central part of the crown is continuously distributed along the circumferential direction of the tire, and the width of the continuous pattern block covers the transverse central area of the tread.
10. A tyre for summer use for vehicles according to claim 2, characterized in that: The inner side surface of the apex rubber (6) is in contact with the outer side surface of the wear resistant layer (55), and the thickness of the apex rubber (6) gradually decreases from the side close to the tire lip portion (61) to the side away from the tire lip portion (61).