RU2748524C1 - Pneumatic tyre - Google Patents

Abstract

FIELD: automobile industry.SUBSTANCE: pneumatic tyre comprises: multiple shoulder units 6 made on the lateral part 2 and arranged in the circumferential direction of the tyre, wherein each of the multiple shoulder units 6 is formed by a connecting groove 8 extending in the circumferential direction of the tyre and by lateral grooves 7 extending in the width direction of the tyre; an auxiliary edge 10 made on the lateral part 2 and extending in the circumferential direction of the tyre; and a protrusion 11 formed on the lateral part 2 and extending from the auxiliary edge 10 so that it protrudes into the lateral groove 7.EFFECT: invention provides efficient damage protection, efficient cooling and traction characteristics, increases the stiffness of the auxiliary edge, provides efficient snow removal in the lateral grooves and provides the vertical deformation rate of the lateral parts.11 cl, 3 dwg

Description

FIELD OF TECHNOLOGY

[0001] The present invention relates to a pneumatic tire.

LEVEL OF TECHNOLOGY

[0002] The conventionally known pneumatic tire includes turbulent flow projections that are provided on the tire surface at intervals in the tire circumferential direction and extend from the inner circumference to the outer circumference (see Patent Document 1).

[0003] Such a conventional pneumatic tire contains only turbulent flow projections on the lateral portions of the pneumatic tire to provide cooling efficiency, however, it is unclear whether the vertical deformation amount of the tire can be reduced or not. In addition, the projections are designed to create a turbulent flow, and thus it is clear that the projections are not designed to remove the remaining snow in the grooves, which is a problem with winter tires.

KNOWN TECHNOLOGY DOCUMENTS

PATENT DOCUMENTS

[0004] Patent Document 1: JP 5374362 B

DISCLOSURE OF THE INVENTION

PROBLEMS TO BE SOLVED BY THE INVENTION

[0005] An object of the present invention is to provide a pneumatic tire that provides increased stiffness of a reinforcing rib for traction performance, improved damage protection and cooling performance, smooth snow evacuation from the lateral groove and reduced vertical deformation of the side portion.

WAYS TO SOLVE PROBLEMS

[0006] One aspect of the present invention comprises:

a plurality of shoulder blocks provided on a side portion and disposed in the tire circumferential direction, each of the plurality of shoulder blocks formed by a connecting groove extending in the tire circumferential direction and lateral grooves extending in the tire width direction;

an auxiliary rib provided on the side portion and extending in the circumferential direction of the tire; and

a projection formed on the side part and extending from the auxiliary rib so that it protrudes into the transverse groove.

[0007] With this configuration, the protrusion protects the side portion and increases the rigidity of the reinforcing rib and thereby improves the traction characteristics of the tire. The protrusion causes the air passing over the tire surface to form a turbulent flow to ensure cooling efficiency. In addition, the protrusion ensures that snow trapped in the lateral grooves is properly evacuated.

[0008] The protrusion preferably includes first protrusions and second protrusions that differ in the amount of protrusion into the lateral groove and are alternately located in the tire circumferential direction.

[0009] In a preferred embodiment, the width of the projection gradually decreases towards the end of the apex of the projection.

[0010] The protrusion preferably comprises an inclined surface that becomes closer to the lower surface of the lateral groove towards the end of the apex of the protrusion.

TECHNICAL RESULT PROVIDED BY THE INVENTION

In accordance with the present invention, there is provided a projection extending from a reinforcing rib into a lateral groove. This increases the stiffness of the reinforcing rib for traction performance, enhances damage protection and cooling performance, and smoothly evacuates snow from the lateral groove.

BRIEF DESCRIPTION OF DRAWINGS

[0012]

FIG. 1 is a perspective view showing a portion of a pneumatic tire according to the present invention;

FIG. 2 is a partial expanded view of the pneumatic tire shown in FIG. one;

FIG. 3A is a partial enlarged view of Figure 2;

FIG. 3B is a longitudinal sectional view of the first projection shown in FIG. 3A; and

FIG. 3C is a longitudinal sectional view of the second projection shown in FIG. 3A.

CARRYING OUT THE INVENTION

[0013] An embodiment of the present invention will now be described with reference to the accompanying drawings. In addition, the following descriptions are essentially illustrative only and do not limit the present invention, its application or its uses. In addition, the figures are schematic views, and the ratio of each size and the like. in the figures is different from the actual one.

[0014] FIG. 1 is a perspective view showing a portion of a pneumatic tire according to the present invention. Although not shown, the pneumatic tire has a configuration in which a carcass is stretched between a pair of bead cores, a belt is wound around the outer peripheral side of the intermediate carcass portion for reinforcement, and the tread portion 1 is located on the outer diameter side of the tire. FIG. 1 does not show the sipes 9 formed on the tread portions 3 of the tread portion 1.

[0015] FIG. 2 is a partial exploded view showing the tread pattern of the pneumatic tire shown in FIG. 1. The tread pattern includes a tread portion 1 that comes into contact with the road surface, and side portions 2 on both sides of the tread portion 1. The tread portions 3 constituting the tread pattern are connected to each other at the center in the tire width direction (indicated arrow W in Fig. 2), which extends in the tire circumferential direction (indicated by an arrow R in FIG. 2), and is spaced in the tire circumferential direction and extends to both ends in the tire width direction.

[0016] The beading portions 3 comprise a central rib 4 that is elongated in the tire circumferential direction at the center in the tire width direction. In addition, the tread sections 3 comprise center blocks 5 and shoulder blocks 6, each of which extends in a tire width direction.

[0017] The center blocks 5 and shoulder blocks 6 are disposed at predetermined intervals in the tire circumferential direction and are formed by the lateral grooves 7 and the connecting grooves 8, each of the connecting grooves 8 allowing the adjacent lateral grooves 7 to be connected to each other in the tire circumferential direction, and the lateral grooves 7 extend outward in the tire width direction and diagonally in the tire circumferential direction.

[0018] The lateral grooves 7 include first lateral grooves 7a and second lateral grooves 7b that are wider than the first lateral grooves. The first lateral grooves 7a and the second lateral grooves 7b are alternately arranged in the tire circumferential direction. In addition, the lateral grooves 7 formed on one side of the center line O (tire center line) located in the center in the tire width direction are arranged differently than the lateral grooves formed on the other side of the center line O in the tire width direction and in circumferential direction of the tire.

[0019] The mating grooves 8 include first mating grooves 8a located closer to the tire centerline and second mating grooves 8b located outwardly in the tire width direction. The first connecting grooves 8a and the second connecting grooves 8b are alternately arranged in the tire circumferential direction. The first connecting grooves 8a separate the first center blocks 5a from the first shoulder blocks 6a. In addition, the second connecting grooves 8b separate the second center blocks 5b from the second shoulder blocks 6b. The second center blocks 5b are longer than the first center blocks 5a, and the second shoulder blocks 6b are shorter than the first shoulder blocks 6a.

[0020] The central rib 4 and the central blocks 5 comprise a plurality of sipes 9 spaced at predetermined intervals so that they intersect the direction of extension of the central rib 4 and the central blocks 5. Each of the sipes 9 contains straight portions 9a that are connected to the lateral grooves 7 on either side of them, and a corrugated section 9b, which is connected to the straight sections.

[0021] Each of the shoulder blocks 6 includes three rows of sipes 9 located along the extension direction of each of the shoulder blocks 6. One of the straight portions in each of the sipes 9 is connected to one of the connecting grooves 8, and the end of the other of the straight portions is located at the border between the tread part 1 and one of the two side parts 2.

[0022] The peripheral edges of the tire comprise minor ribs 10, each of which extends in an annular manner in the circumferential direction of the tire. Each of the minor ribs 10 comprises projections 11 extending to a corresponding one of the lateral grooves 7. The projections 11 include first projections 11a, respectively, extending into the first transverse grooves, and second projections 11b, respectively, extending into the second transverse grooves.

[0023] As shown in FIG. 3A and 3B, the first projections 11a have a relatively small projection amount L1 into the respective first lateral grooves 7a (length in the direction of the tire outer diameter measured from the inner peripheral edge of the minor rib 10). Specifically, the projection amount L1 is in the range of 5 mm to 50 mm (20 mm in the present embodiment). The first projections 11a have a height H (a height measured from the surface of the side portion 2) that is equal to the height of the auxiliary ribs 10 and ranges from 0.5 mm to 10 mm (1.2 mm in the present embodiment). Each of the vertices of the first protrusions 11a includes an inclined surface 11c gradually approaching the lower surface of the individual transverse groove 7. The angle α formed by the inclined surface 11c and the upper surface 11d of each first protrusion 11a is in the range from 10 ° to 80 ° (35 ° in present embodiment). Each of the first protrusions 11a gradually tapers towards its apex, and the angle θ1 formed by both of its side surfaces ranges from 3 ° to 30 ° (14 ° in the present embodiment). The angle θ1 is set to a larger value than the angle θ2 formed by both side surfaces of the first lateral groove 7a on the side portions 2. In addition, the inclined surface 11c is formed within a length L2 from the top of each first projection 11a. The length L2 ranges from 3 mm to 50 mm (7.5 mm in the present embodiment). In addition, the top of each first projection 11a has a width w1 in the range of 1 mm to 20 mm (1.8 mm in the present embodiment), in which the corresponding one of the first lateral grooves 7a has a width w2 in the range of 3 mm to 30 mm (9.9 mm in the present embodiment). It should be noted that the center line C1 of each first projection 11a substantially coincides with the center line C2 of the corresponding one of the first lateral grooves 7a.

[0024] As shown in FIG. 3A and 3C, the second protrusions 11b have a larger protrusion amount L3 from the minor rib 10 than the first protrusions and extend to a region near the boundary between the tread portion 1 and one of the side portions 2. In particular, the protrusion amount L3 is in the range of 10 mm up to 70 mm (26 mm in the present embodiment). The height H of the second projections 11b is equal to the height of the first projections 11a. Each of the tops of the second projections 11b includes an inclined surface 11e that is similar to the inclined surface of the first projections 11a. The angle β formed by the inclined surface 11e and the upper surface 11f of each second projection 11b is in the range of 10 ° to 80 ° (40 ° in the present embodiment). Each of the second protrusions 11b gradually tapers towards its apex, and the angle θ3 formed by both of its side surfaces is in the range of 3 ° to 30 ° (9 ° in the present embodiment). The angle θ3 is set to a larger value than the angle θ4 formed by both side surfaces of the second lateral groove 7b on the side portions 2. In addition, the inclined surface 11e is formed within a length L4 from the top of each second projection 11b. The length L4 ranges from 5 mm to 60 mm (13 mm in the present embodiment). In addition, the top of each second projection 11b has a width w3 in the range of 1 mm to 20 mm (2.2 mm in the present embodiment), in which the corresponding one of the second lateral grooves 7b has a width w4 in the range of 3 mm to 30 mm (10.2 mm in the present embodiment). It should be noted that the center line C3 of each second projection 11b substantially coincides with the center line C4 of the corresponding one of the second lateral grooves 7b.

[0025] Thus, the first projections 11a and second projections 11b having different projection amounts are alternately disposed in the tire circumferential direction, which provides an appropriate balance of stiffness for the side portions 2, each of which comprises first shoulder blocks 6a and second shoulder blocks 6b, having different lengths. Since the shoulder blocks 6a and 6b have different stiffness due to the difference in length, so-called sawtooth tread wear is likely to occur during movement. However, the occurrence of such sawtooth tread wear is reduced by providing the first shoulder blocks 6a and the second shoulder blocks 6b with increased rigidity by means of the first shoulder blocks 11a and the second shoulder blocks 6b, and by making the first shoulder blocks 6a and second shoulder blocks 6b resistant to deformation. In particular, winter tires can reduce the rigidity due to the large number of sipes 9 also formed on the shoulder blocks 6. However, such a decrease in rigidity is constrained by the projections 11, and thus the required cornering characteristics can be achieved.

[0026] In addition, the projections 11 gradually taper towards their peaks, on which the inclined surfaces 11c are located. This configuration allows the snow to evacuate smoothly even if snow remains in the transverse grooves 7, since the deformation of the side portions 2, which occurs when the tread portion 1 contacts the ground, causes the projections 11 to act on the snow from the underside in the transverse grooves 7.

[0027] Each of the shoulder blocks 6 includes a projection 12 at its outer end in the tire width direction. The protrusion 12 comprises a first sawtooth shoulder 12a and two second parallelogram-shaped shoulder protrusions 12b formed along each portion of the barb.

[0028] A pneumatic tire having protrusions 11 with the above-described configuration achieves the following technical results.

(1) The protrusions 11 prevent foreign objects such as curbs from contacting the side portions 2, and thus excellent damage protection performance can be provided.

(2) The protrusions 11 convert the wind generated while driving into a turbulent flow, and thus heat dissipation is improved and excellent cooling efficiency can be achieved.

(3) The protrusions 11 reinforce the auxiliary ribs 10 by increasing their rigidity, and thus excellent traction performance can be provided.

(4) The projections 11 are located inside the respective transverse grooves 7, and thus the snow in the side grooves 7 can be deflected. In other words, snow trapped in the lateral grooves 7 moves to the inclined surfaces of the projections 11 when the tread portion 1 contacts the ground and causes deformation. Thus, snow does not remain in the lateral grooves 7, and a good running state can be ensured.

(5) The projections 11 increase the rigidity of the shoulder blocks 6, and thus sawtooth wear of the tread can be reduced and the required cornering performance can be achieved.

LIST OF REFERENCE SYMBOLS

[0029]

1: Protective part

2: Side

3: Running section

4: Center rib

5: Central unit

5a: First central block

5b: Second center block

6: Shoulder block

6a: First shoulder block

6b: Second shoulder block

7: Transverse groove

7a: First lateral groove

7b: Second lateral groove

8: Connecting groove

8a: First connecting groove

8b: Second connecting groove

9: Slotted groove

10: Auxiliary rib

11: Ledge

11a: First ledge

11b: Second lip

11c: Inclined surface

12: Shoulder protrusion

12a: First shoulder protrusion

12b: Second shoulder protrusion.

Claims (21)

1. A pneumatic tire containing: a plurality of shoulder blocks provided on a side portion and disposed in the tire circumferential direction, each of the plurality of shoulder blocks formed by a connecting groove extending in the tire circumferential direction and lateral grooves extending in the tire width direction; a rib formed on a side portion located inwardly in the tire radius direction with respect to the plurality of shoulder blocks and extending in the tire circumferential direction to extend in the tire circumferential direction continuously and annularly; and a protrusion made on the side part, extending outward in the tire width direction from the rib, having a tip end configured to be located in the transverse groove, and made in one piece with the lower surface of the transverse groove. 2. The pneumatic tire of claim 1, wherein the projection includes first projections and second projections that differ in the amount of projection into the lateral groove and alternately arranged in the circumferential direction of the tire. 3. The pneumatic tire of claim 1, wherein the width of the projection in the tire circumferential direction is narrower than the width between two adjacent shoulder blocks in the tire circumferential direction. 4. The pneumatic tire of claim 1, wherein the width of the lateral groove in the tire circumferential direction is greater than the width of the projection in the tire circumferential direction. 5. The pneumatic tire of claim 1, wherein at least one of the shoulder blocks is formed with sipes. 6. The pneumatic tire of claim 1, wherein the height of the end of the projection apex from the bottom surface of the lateral groove is less than the height of the shoulder block from the bottom surface of the lateral groove in the tire width direction. 7. A pneumatic tire according to claim 2, wherein the lateral grooves comprise: a first lateral groove in which the tip end of the first projection is located and which has a first width in the tire circumferential direction; and a second lateral groove in which the end of the apex of the second projection is located and which has a second width in the tire circumferential direction that is different from the first width. 8. Pneumatic tire according to claim 1, in which the shoulder block contains side walls extending in the direction of the tire radius, the projection comprises side walls extending in the direction of the tire radius, which respectively face the side walls of the shoulder block, and at least one of the side walls of the projection and at least one of the side walls of the shoulder block are not parallel when viewed in the tire width direction. 9. A pneumatic tire according to claim 8, in which the protrusion is tapered when viewed in the tire width direction, at the end of the apex of the protrusion, the end of the apex of the protrusion is narrower when viewed in the direction of the tire width. 10. The pneumatic tire of claim 1, wherein the width of the projection narrows toward an end of the top of the projection. 11. Pneumatic tire according to one of paragraphs. 1-10, in which the protrusion comprises an inclined surface that becomes closer to the lower surface of the lateral groove towards the end of the apex of the protrusion.

Images