JP2013151240A - Vehicle tire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vehicle tire improved in hydroplaning resistance by preventing the degradation of the water drainage efficiency of fluid entering circumferential grooves.SOLUTION: A vehicle tire includes: circumferential grooves formed on a tread surface, and extending in a circumferential direction of the tire; and groove wall protrusions protruding from groove walls of the circumferential grooves and extending in a groove depth direction, and formed along the circumferential groove at a predetermined interval.

Description

  The present invention relates to a vehicle tire.

  There is a vehicle tire in which a circumferential groove extending in the tire circumferential direction is formed on a tread surface of the vehicle tire, and a fluid such as rainwater between the tire and a road surface enters the groove of the circumferential groove while running. . Further, there is a vehicle tire in which the groove width of the circumferential groove is changed in the tire circumferential direction (for example, Patent Document 1).

  By changing the groove width of the circumferential groove in the tire circumferential direction, the hydroplaning resistance can be improved as compared with the straight circumferential groove. However, since the frictional force acts on the fluid flowing in contact with the groove wall and the groove bottom of the circumferential groove, the flow velocity is slower than that of the fluid flowing in the center of the circumferential groove. Due to this difference in flow velocity, a vortex is generated in the vicinity of the groove wall of the circumferential groove and in the vicinity of the groove bottom to push the fluid in the direction opposite to the flow, and the drainage efficiency from the circumferential groove is reduced.

JP 2011-245913 A

  An object of the present invention is to provide a vehicle tire that suppresses a decrease in drainage efficiency of a fluid that has entered a circumferential groove and improves hydroplaning resistance.

  The vehicle tire according to claim 1 is formed on a tread surface, extends in a tire circumferential direction, protrudes from a groove wall of the circumferential groove, extends in a groove depth direction, and extends in the groove depth direction. , And groove wall protrusions formed at predetermined intervals along.

  In the vehicle tire according to claim 1, a circumferential groove extending in the tire circumferential direction is formed on the tread surface, and the circumferential groove protrudes from the groove wall of the circumferential groove and extends in the groove depth direction. Groove wall protrusions are formed at predetermined intervals along the circumferential groove. Since the groove wall protrusion blocks the force of pushing back the fluid caused by the vortex generated in the vicinity of the groove wall of the circumferential groove in the direction opposite to the flow, it is possible to suppress a decrease in drainage efficiency.

  A vehicle tire according to a second aspect is the vehicle tire according to the first aspect, wherein the circumferential groove protrudes from a groove bottom of the circumferential groove separately from the groove wall protruding portion. Groove bottom protrusions extending in the groove width direction are formed at predetermined intervals along the circumferential groove.

  In the vehicle tire according to claim 2, apart from the groove wall protrusions, groove bottom protrusions that protrude from the groove bottom of the circumferential groove and extend in the groove width direction are formed at predetermined intervals along the circumferential groove. Has been. Since the groove bottom protrusion blocks the force of pushing back the fluid caused by the vortex generated in the vicinity of the groove bottom of the circumferential groove in the direction opposite to the flow, it is possible to suppress a decrease in drainage efficiency.

  The vehicle tire according to claim 3 is the vehicle tire according to claim 1 or 2, wherein the vehicle tire is inclined downward from the edge portion of the circumferential groove to the center of the groove bottom and inclined with respect to the tire circumferential direction. The ribs extending from the center to the edge part at an upward slope obliquely with respect to the tire circumferential direction, and ribs that cross the circumferential groove are provided at predetermined intervals along the circumferential groove. Is also formed on the side wall of the rib.

  In the vehicle tire according to claim 3, the tire extends from the edge portion of the circumferential groove obliquely to the tire circumferential direction with a downward slope toward the center of the groove bottom, and rises upward from the center to the edge portion with respect to the tire circumferential direction. Ribs extending obliquely and crossing the circumferential groove are provided at predetermined intervals along the circumferential groove. Thereby, since the circumferential groove divided by the rib has the same function as the lateral groove extending in the tire width direction, the braking performance of the vehicle is improved. Moreover, since it is not necessary to separately form a lateral groove on the tread surface, it is possible to suppress a decrease in block rigidity caused by dividing the tread.

  Furthermore, since the groove wall protrusions are also formed on the rib side walls, the force that pushes the fluid due to the vortex generated in the vicinity of the rib side walls in the direction opposite to the flow is blocked by the groove bottom protrusions, reducing drainage efficiency. Can be suppressed.

  The vehicle tire according to claim 4 is the vehicle tire according to claim 1 or 2, wherein the circumferential groove has a cross-sectional area of the circumferential groove cut in a tire radial direction. Are formed so as to periodically increase and decrease along the line.

  In the vehicle tire according to the fourth aspect, the cross-sectional area of the circumferential groove cut in the tire radial direction periodically increases and decreases along the tire circumferential direction. Thereby, since the cross-sectional area cut | disconnected in the tire radial direction of the circumferential groove | channel which is earth | grounded on the road surface increases / decreases with rolling of a tire and squeezes out a fluid, a fluid can be drained efficiently.

  A vehicle tire according to a fifth aspect is the vehicle tire according to the fourth aspect, wherein the groove wall of the circumferential groove meanders.

  In the vehicle tire according to the fifth aspect, since the groove wall of the circumferential groove meanders, the groove width periodically changes along the tire circumferential direction. As a result, the groove width of the circumferential groove that is in contact with the road surface increases and decreases with the rolling of the tire to squeeze out the fluid, so that the fluid can be drained efficiently.

  A vehicle tire according to a sixth aspect is the vehicle tire according to any one of the first to fifth aspects, wherein a plurality of the circumferential grooves are formed on the tread surface.

  In the vehicle tire according to claim 6, since a plurality of circumferential grooves are formed in the let, compared with the case where only one circumferential groove is formed, the fluid that has entered the circumferential grooves The amount of drainage can be increased.

  The vehicle tire according to claim 7 is the vehicle tire according to any one of claims 1 to 6, wherein the groove wall projecting section cut along the groove bottom, and the groove wall The cross-sectional shape of the groove bottom protrusion cut along the line is a triangle.

  In the vehicle tire according to the seventh aspect, the cross-sectional shape of the groove wall protruding portion cut along the groove bottom and the cross-sectional shape of the groove bottom protruding portion cut along the groove wall are triangular. Thereby, the fluid that has entered the groove wall and the groove bottom of the circumferential groove smoothly flows to the center of the circumferential groove along the slope of the groove wall protrusion and the groove bottom protrusion, and the groove wall and groove of the circumferential groove. Peeled from the bottom.

  The vehicle tire according to claim 8 is the vehicle tire according to any one of claims 1 to 7, wherein the groove wall protrusion and the groove bottom protrusion have a protrusion height H of 0. The width W of the root portion is formed to be 0.3 mm or less, and the pitch P is formed to be 1 to 5 times the width W.

  In the vehicle tire according to claim 8, the groove wall protrusion and the groove bottom protrusion are formed such that the protrusion height H is 0.2 mm or less, the width W of the root portion is 0.3 mm or less, and the pitch P is formed 1 to 5 times the width W. Here, if the pitch P between the groove wall protrusion and the groove bottom protrusion is narrower than the width W, the groove wall protrusion and the groove bottom protrusion are continuously formed along the circumferential groove. Increases resistance to fluid. In addition, if the pitch P between the groove wall protrusions and the groove bottom protrusions is greater than 5 times the width W, the interval between the vortexes generated between adjacent groove wall protrusions and groove bottom protrusions becomes wide. However, the force that pushes over the groove wall protruding portion and the groove bottom protruding portion and pushes it back in the direction opposite to the flow of the fluid cannot be blocked, and the drainage efficiency decreases.

  Since this invention set it as said structure, it can suppress the fall of the drainage efficiency of the fluid which entered into the circumferential groove | channel, and can provide the vehicle tire which improves hydroplaning resistance.

1 is a perspective view showing a tread surface of a vehicle tire according to a first embodiment of the present invention. 1 is a plan view showing a tread surface of a vehicle tire according to a first embodiment of the present invention. It is the sectional view on the AA line of FIG. It is the expanded sectional view which cut the tire for vehicles concerning a 1st embodiment of the present invention along the tire equator line. It is an expanded sectional view showing the 1st peripheral groove concerning a 1st embodiment of the present invention. It is a principal part enlarged view for demonstrating the effect | action of the 1st groove wall protrusion part which concerns on 1st Embodiment of this invention. It is a principal part enlarged view for demonstrating the effect | action of the 1st groove bottom protrusion part which concerns on 1st Embodiment of this invention. FIG. 3 is a sectional view taken along line B-B in FIG. 2. FIG. 3 is an enlarged plan view of a second circumferential groove according to the first embodiment of the present invention. It is a principal part enlarged view for demonstrating the flow of the fluid which entered into the 2nd circumferential groove | channel which concerns on 1st Embodiment of this invention. It is a principal part enlarged view which shows the 1st circumferential groove | channel which concerns on 2nd Embodiment of this invention. It is a principal part enlarged view for demonstrating the flow of the fluid which entered into the 1st circumferential groove | channel concerning 2nd Embodiment of this invention. It is a principal part enlarged view which shows the modification of the 1st circumferential groove | channel concerning 2nd Embodiment of this invention.

(First embodiment)
A vehicle tire 10 according to a first embodiment of the present invention will be described with reference to FIGS. In the drawing, the arrow TW indicates the width direction of the vehicle tire 10, the arrow TR indicates the radial direction of the vehicle tire 10, and the arrow TC indicates the circumferential direction of the vehicle tire 10. Reference sign CL indicates the equator line of the vehicle tire 10, and reference sign DCL indicates the center line of the second circumferential groove 18.

  As shown in FIG. 1, the 1st circumferential groove | channel 14 extended in the tire circumferential direction TC is formed in the tread surface 12 of the center of the tire width direction TW of the vehicle tire 10 which concerns on this embodiment. The first circumferential groove 14 extends straight with a constant groove width, and as shown in FIG. 3, the edge portion 14B between the groove wall 14A of the first circumferential groove 14 and the tread surface 12 is R. It has a shape.

  The groove depth D of the first circumferential groove 14 is formed to a depth that does not reach a ply (not shown) formed inside the vehicle tire 10. In the present embodiment, the groove depth D of the first circumferential groove 14 is 8.4 mm in a new state. In addition, the groove width W of the first circumferential groove 14 is not particularly limited, but in the present embodiment, it is 4 mm as an example.

  As shown in FIG. 1, second circumferential grooves 18 extending in the tire circumferential direction TC are formed on both sides of the first circumferential groove 14 in the tire width direction TW with a land portion 16 extending in the circumferential direction interposed therebetween. . The second circumferential groove 18 is formed wider than the first circumferential groove 14, and the groove depth of the second circumferential groove is the same as the groove depth D (8.4 mm) of the first circumferential groove. is there.

  In the groove of the second circumferential groove 18, a plurality of ribs 20 that divide the second circumferential groove 18 at a predetermined interval are formed along the second circumferential groove 18. Accordingly, the second circumferential groove 18 has a configuration in which the ribs 20 and the narrow grooves 22 are alternately provided along the tire circumferential direction TC.

  As shown in FIGS. 2 and 8, the rib 20 extends obliquely with respect to the tire circumferential direction TC with a downward slope from one edge portion 18B of the second circumferential groove 18 toward the center of the groove bottom 18C. Furthermore, it extends obliquely with respect to the tire circumferential direction TC with an upward slope toward the other edge portion 18B. That is, when the cross section of the rib 20 is viewed from the tire circumferential direction TC side, the center 20A of the rib 20 has a shape recessed toward the groove bottom 18C side of the second circumferential groove 18.

  The width of the rib 20 is the widest end portion 20B on the edge portion 18B side of the second circumferential groove 18 and is narrower toward the center 20A of the rib 20. The groove width of the narrow groove 22 is also the edge portion. The side 18B is widest and narrows toward the center of the second circumferential groove 18. The end 20B of the rib 20 is formed such that an angle θ1 formed by the rib 20 and the straight line L1 orthogonal to the tire equator line CL is smaller than a predetermined angle. And an angle θ2 formed by a straight line L2 orthogonal to the tire equator line CL is formed to be larger than a predetermined angle.

  Here, a first groove wall protrusion 24 and a first groove bottom protrusion 26 are formed in the first circumferential groove 14, and a second groove wall protrusion 28 is formed in the second circumferential groove 18. And a second groove bottom protrusion 30 is formed. The first groove wall protrusion 24, the second groove wall protrusion, the first groove bottom protrusion 26, and the second groove bottom protrusion 30 are drawn with exaggerated sizes for convenience of explanation.

  As shown in FIG. 3, the groove wall 14A on both sides of the first circumferential groove 14 is formed with a first groove wall protrusion 24 that protrudes toward the opposite groove wall. The first groove wall projecting portion 24 extends in the groove depth direction from the edge portion 14B of the first circumferential groove 14 to the groove bottom 14C, and as shown in FIG. 4, a predetermined interval is provided along the tire circumferential direction TC. It is formed with.

  The first circumferential groove 14 is formed with a first groove bottom protrusion 26 that protrudes from the groove bottom 14C and extends in the groove width direction. The first groove bottom protrusions 26 are formed integrally with the first groove wall protrusions 24 and are formed at the same intervals as the first groove wall protrusions 24 along the tire circumferential direction.

  Here, as shown in FIG. 4, the cross-sectional shape of the first groove bottom protrusion 26 cut along the groove wall 14A is a triangle, and the protrusion height H1 of the first groove bottom protrusion 26 is It is formed to be 0.2 mm or less. Moreover, the width W1 of the base part of the 1st groove bottom protrusion part 26 is formed below 0.3 mm, and the pitch P1 of the 1st groove bottom protrusion part 26 is 1-5 times the length of W1. Has been. In this embodiment, as an example, H1 is 0.2 mm, W1 is 0.3 mm, and P1 is 1.2 mm, which is four times W1.

  As shown in FIG. 5, the cross-sectional shape of the first groove wall protrusion 24 cut along the groove bottom 14 </ b> C of the first circumferential groove 14 is a triangle like the cross-sectional shape of the first groove bottom protrusion 26. ing. Further, the protrusion height H1, the width W1 of the root portion, and the pitch P1 of the first groove bottom protrusion 26 are formed such that H1 is 0.2 mm or less, and W1 is 0, similarly to the first groove bottom protrusion 26. .3 mm or less, and P1 is formed 1 to 5 times as long as W1. In the present embodiment, the dimensions are the same as those of the first groove bottom protrusion 26 (H1 = 0.2 mm, W1 = 0.3 m, P1 = 1.2 mm).

  As shown in FIG. 8, first groove wall protrusions 24 are formed along the second circumferential groove 18 at predetermined intervals on the groove wall 18 </ b> A of the second circumferential groove 18. Further, as shown in FIG. 9, the groove wall 22 </ b> A of the narrow groove 22 constituting the second circumferential groove 18, that is, the side wall of the rib 20 has a predetermined distance toward the groove wall 22 </ b> A of the opposing narrow groove 22. Thus, the second groove wall protrusion 28 is formed. A second groove bottom protrusion 30 extending in the groove width direction of the narrow groove 22 is formed on the groove bottom 22 </ b> C of the narrow groove 22. The second groove bottom protrusion 30 is formed integrally with the first groove wall protrusion 24 or the second groove wall protrusion 28.

  Here, the cross-sectional shape obtained by cutting the second groove bottom protrusion 30 along the groove wall 22A of the fine groove 22 and the cross-sectional shape obtained by cutting the second groove wall protrusion 28 along the groove bottom 22C of the fine groove 22 are: It has become a triangle. The protrusion height H2 of the second groove bottom protrusion 30 and the second groove wall protrusion 28 is formed to be 0.2 mm or less, the width W2 of the root portion is formed to be 0.3 mm or less, and the pitch P2 is W2. The length is 1 to 5 times. In the present embodiment, the first groove bottom protrusion 26 and the first groove wall protrusion 24 have the same dimensions (H2 = 0.2 mm, W2 = 0.3 m, P2 = 1.2 mm).

  In the present embodiment, the first groove bottom protrusion 26 and the first groove wall protrusion 24 are integrally formed with the same dimensions, but the dimensions of the first groove bottom protrusion 26 and the first groove wall protrusion 24 are as follows. They may be formed with different dimensions, and the dimensions of the second groove bottom protrusion 30 and the second groove wall protrusion 28 are different from the dimensions of the first groove bottom protrusion 26 and the first groove wall protrusion 24. You may form by a dimension.

  Alternatively, only the first groove wall protrusion 24 may be formed without forming the first groove bottom protrusion 26. Further, the first groove bottom protrusion 26 and the first groove wall protrusion 24 may be formed separately. For example, the first groove bottom protrusions 26 may be formed between adjacent first groove wall protrusions 24 along the tire circumferential direction.

  Next, the operation of the vehicle tire 10 according to the present embodiment will be described. As shown in FIG. 2, the vehicular tire 10 according to the present embodiment includes one first circumferential groove 14 and two second circumferential grooves 18 formed on the tread surface 12, so that the circumferential direction Compared with a vehicle tire in which only one groove is formed, the amount of fluid drainage can be increased.

  Moreover, since the rib 20 which crosses the 2nd circumferential groove 18 is formed in the 2nd circumferential groove 18, the 2nd circumferential groove 18 divided | segmented by the rib 20 is a lateral groove extended in the tire width direction TW. It becomes the narrow groove 22 provided with the same function. Thereby, it is not necessary to separately form a lateral groove extending in the tire width direction TW on the tread surface 12, and a decrease in block rigidity due to the division of the tread surface 12 can be suppressed.

  Further, as shown in FIG. 8, the center 20 </ b> A of the rib 20 has a shape recessed toward the groove bottom 18 </ b> C side of the second circumferential groove 18, so that the tread surface 12 is worn and the second circumferential groove 18 As the groove depth becomes shallower, the contact area of the rib 20 that contacts the road surface increases, and the braking performance can be improved.

  As shown in FIG. 2, the end 20B of the rib 20 in the tire width direction TW is formed such that an angle θ1 formed by the rib 20 and a straight line L1 orthogonal to the tire equator line CL is smaller than a predetermined angle. Therefore, the rigidity in the tread width direction TW can be improved as compared with the case where the ribs 20 are formed linearly. On the other hand, the center 20A of the rib 20 is formed such that an angle θ2 formed by the rib 20 and the straight line L2 orthogonal to the tire equator line CL is larger than a predetermined angle, that is, formed along the tire circumferential direction TC. Therefore, compared with the case where the rib 20 is formed along the tire width direction TW, the drainage efficiency of the fluid flowing through the second circumferential groove 18 can be improved.

  Next, the operation of the first groove wall protrusion 24 and the first groove bottom protrusion 26 formed in the first circumferential groove 14 will be described. When the vehicular tire 10 enters the puddle during traveling, the water in the puddle is compressed between the road surface and the vehicular tire 10 by the load of the vehicular tire 10 and is formed in the first circumference formed in the vehicular tire 10. Enter the directional groove 14 and the second circumferential groove 18. At this time, as shown in FIG. 6, the water that has entered the first circumferential groove 14 moves in the first circumferential groove 14 in the direction opposite to the traveling direction of the vehicle as the vehicle tire 10 rolls ( Flows in the direction of the arrow in the figure.

  Here, the water flowing in the vicinity of the groove wall 14 </ b> A of the first circumferential groove 14 receives a frictional force from the groove wall 14 </ b> A, so that the flow velocity is slower than the water flowing in the center of the first circumferential groove 14. Due to the difference in the flow velocity of water, a plurality of vortices C are generated along the first circumferential groove 14 in the vicinity of the groove wall 14 </ b> A of the first circumferential groove 14. The vortex C tries to push back the water flowing in the first circumferential groove 14 in the direction opposite to the flow, but the first groove wall protrusion formed in the groove wall 14A of the first circumferential groove 14. Since 24 blocks the flow of the vortex C, the force of the vortex C does not act on the water flowing through the first circumferential groove 14. Thereby, the water in the 1st circumferential groove | channel 14 is drained without staying in the 1st circumferential groove | channel 14, and can suppress the fall of drainage efficiency.

  Moreover, the cross-sectional shape which cut | disconnected the 1st groove wall protrusion part 24 along the groove bottom 14C of the 1st circumferential groove 14 is a triangle, and it is with respect to the flow direction of the water which flows through the inside of the 1st circumferential groove 14 Since it is composed of an inclined slope, the water that has entered the groove wall 14A of the first circumferential groove 14 smoothly flows to the center of the first circumferential groove 14 along the slope of the first groove wall protrusion 24. . Thereby, the water that has entered the groove wall 14A of the first circumferential groove 14 can be peeled off from the groove wall 14A.

  Here, as shown in FIG. 5, the protrusion height H <b> 1 of the first groove wall protrusion 24 is formed to be 0.2 mm or less, and therefore occurs in the vicinity of the groove wall 14 </ b> A of the first circumferential groove 14. The vortex C becomes a small vortex C in proportion to the size of the first groove wall protrusion 24. For this reason, the vortex C generated in the vicinity of the groove wall 14 </ b> A does not hinder the drainage of water flowing through the center of the first circumferential groove 14. Further, the width W1 of the root portion of the first groove bottom protrusion 26 is formed to be 0.3 mm or less, and the slope forming the first groove wall protrusion 24 becomes the tire width direction TW as the width W1 is reduced. Therefore, the water that has entered the groove wall 14A of the first circumferential groove 14 can flow more smoothly to the center of the first circumferential groove 14.

  Further, since the pitch P1 of the first groove bottom protrusions 26 is formed to be larger than the width W1, the first groove wall protrusions 24 are not continuously formed along the first circumferential grooves 14. It is possible to suppress an increase in resistance to water flowing through the first circumferential groove 14. Further, since the pitch P1 of the first groove bottom protrusion 26 is shorter than five times the width W1, the vortex C generated in the vicinity of the groove wall 14A of the first circumferential groove 14 causes the first groove wall protrusion Never get past the 24 and push the water back.

  Further, as shown in FIG. 7, in the vicinity of the groove bottom 14 </ b> C of the first circumferential groove 14, water that flows through the groove bottom 14 </ b> C of the first circumferential groove 14 and the center and upper part of the first circumferential groove 14. A plurality of vortices C are generated due to the difference in flow velocity with water, and these vortices C try to push back the water flowing through the first circumferential groove 14 in the direction opposite to the flow. Since the first groove bottom protrusion 26 formed on the groove bottom 14 </ b> C of the groove 14 blocks the flow of the vortex C, the force of the vortex C does not act on the water flowing through the first circumferential groove 14. Thereby, the water in the 1st circumferential groove | channel 14 is drained without staying in the 1st circumferential groove | channel 14, and can suppress the fall of drainage efficiency. In addition, since the cross section of the first groove wall protrusion 24 cut along the groove wall 14A of the first circumferential groove 14 is a triangle, the water that has entered the groove bottom 14C of the first circumferential groove 14 is It flows smoothly along the slope of the first groove bottom protrusion 26 to the center of the first circumferential groove 14. Thereby, the water that has entered the groove bottom 14C of the first circumferential groove 14 can be peeled off from the groove bottom 14C.

  Next, the operation of the second groove wall protrusion 28 and the second groove bottom protrusion 30 formed in the second circumferential groove 18 will be described. Of the water that has entered the second circumferential groove 18, a part of the water flows through the center 20A of the rib 20 shown in FIG. 8 in the tire circumferential direction TC and is drained, and the remaining water is as shown in FIG. It flows through the narrow groove 22 and is drained.

  Here, the water flowing in the vicinity of the groove wall 22 </ b> A of the narrow groove 22 receives frictional force from the groove wall 22 </ b> A. Due to the difference in the flow velocity of water, a plurality of vortices C are generated along the narrow groove 22 in the vicinity of the groove wall 22A of the narrow groove 22. The vortex C tries to push back the water flowing through the narrow groove 22 in the opposite direction to the flow, but the second groove wall protrusion 28 formed on the groove wall 22A of the narrow groove 22 causes the flow of the vortex C to flow. Therefore, the force caused by the vortex C does not act on the water flowing through the narrow groove 22. Thereby, the water in the narrow groove 22 is drained without stagnation in the narrow groove 22, and the decrease in drainage efficiency can be suppressed. Similarly, since the second groove bottom protrusion 30 formed on the groove bottom 22C of the narrow groove 22 blocks the flow of vortices generated in the vicinity of the groove bottom 22C of the narrow groove 22, the water in the narrow groove 22 In addition, the water is drained without stagnation in the narrow groove 22, and a decrease in drainage efficiency can be suppressed. Other operations are the same as those of the first groove wall protrusion 24 and the first groove bottom protrusion 26.

(Second Embodiment)
Next, a vehicle tire 50 according to a second embodiment of the present invention will be described. In addition, about the structure similar to 1st Embodiment, the same code | symbol is attached | subjected and description is abbreviate | omitted. As shown in FIG. 11, the vehicle tire 50 according to the present embodiment is formed with a first circumferential groove 52 extending in the tire circumferential direction TC. The groove wall 52A of the first circumferential groove 52 is formed to meander, and the groove walls 52A of the first circumferential groove 52 facing each other are formed symmetrically with respect to the tire equator line CL. That is, the cross-sectional area of the first circumferential groove 52 cut in the tire radial direction TR is formed so as to periodically increase and decrease along the tire circumferential direction TC.

  A groove wall 52 </ b> A of the first circumferential groove 52 is formed with a first groove wall protruding portion 54 that protrudes toward the groove wall facing the first circumferential groove 52 at a predetermined interval. Further, first groove bottom protrusions 56 are formed at predetermined intervals along the first circumferential groove 52 at the groove bottom 52 </ b> C of the first circumferential groove 52. The first groove wall protrusion 54 extends in the groove depth direction of the first circumferential groove 52, the first groove bottom protrusion 56 extends in the groove width direction of the first circumferential groove 52, and It is formed integrally with the one groove wall protrusion 54. The configuration of the vehicle tire 50 other than the first circumferential groove 52 is the same as that of the vehicle tire 10 according to the first embodiment.

  Next, the operation of the vehicle tire 50 according to this embodiment will be described. As shown in FIG. 12, the groove wall 52A of the first circumferential groove 52 of the vehicle tire 50 according to the present embodiment meanders, so that the groove width of the first circumferential groove 52 is in the tire circumferential direction TC. It changes periodically along. As a result, when the running vehicle tire 50 enters the puddle, the groove width of the first circumferential groove 52 that is in contact with the road surface increases and decreases with the rolling of the tire and enters the first circumferential groove 52. Since the water is squeezed out, the water can be drained efficiently.

  Further, the groove wall 52A of the first circumferential groove 52 and the first groove wall protrusion 54 and the first groove bottom protrusion 56 formed on the groove bottom 52C are water flowing through the center of the first circumferential groove 52. The water in the first circumferential groove 52 stays in the first circumferential groove 52 to block the flow of the vortex C generated by the difference in flow velocity between the water flowing in the vicinity of the groove wall 52A or the groove bottom 52C. It is drained without any problem, and the decline in drainage efficiency can be suppressed. Other operations are the same as those of the vehicle tire 10 according to the first embodiment.

  In the first circumferential groove 52 according to the present embodiment, the groove wall 52A meanders, but the cross-sectional area of the first circumferential groove 52 cut in the tire radial direction TR is along the tire circumferential direction TC. The groove wall 52 </ b> A does not have to meander as long as it is formed so as to increase or decrease periodically. For example, as in the vehicle tire 60 shown in FIG. 13, the first circumferential groove 62 is configured by the narrow width portion 62A, the wide width portion 62B, and the inclined portion 62C between the narrow width portion 62A and the wide width portion 62B. Also good.

  The first embodiment and the second embodiment of the present invention have been described above. However, the present invention is not limited to such embodiments, and can be implemented in various modes without departing from the gist of the present invention. Of course you get. For example, a plurality of first circumferential grooves 14 may be formed on the tread surface 12.

10 vehicle tire 12 tread surface 14 first circumferential groove (circumferential groove)
14A Groove wall 14B Edge portion 14C Groove bottom 18 Second circumferential groove (circumferential groove)
20 Rib 24 First groove wall protrusion (groove wall protrusion)
26 1st groove bottom protrusion (groove bottom protrusion)
28 Second groove wall protrusion (groove wall protrusion)
30 Second groove bottom protrusion (groove bottom protrusion)
50 vehicle tire 52 first circumferential groove (circumferential groove)
54 1st groove wall protrusion (groove wall protrusion)
56 First groove bottom protrusion (groove bottom protrusion)
60 vehicle tire 62 first circumferential groove (circumferential groove)
C Vortex TC Tire circumferential direction TR Tire radial direction TW Tire width direction

Claims (8)

A circumferential groove formed in the tread surface and extending in the tire circumferential direction;
Projecting from the groove wall of the circumferential groove, extending in the groove depth direction, and groove wall protrusions formed at predetermined intervals along the circumferential groove;
A vehicle tire having:   In the circumferential groove, apart from the groove wall protrusion, a groove bottom protrusion that protrudes from the groove bottom of the circumferential groove and extends in the groove width direction is formed at a predetermined interval along the circumferential groove. The vehicle tire according to claim 1. The circumferential groove extends obliquely with respect to the tire circumferential direction with a downward inclination from the edge portion of the circumferential groove to the center of the groove bottom, and extends obliquely with respect to the tire circumferential direction with the upward inclination from the center to the edge portion. Ribs across the circumferential groove are provided at predetermined intervals along the circumferential groove,
The vehicle tire according to claim 1, wherein the groove wall protruding portion is also formed on a side wall of the rib.   The vehicle tire according to claim 1, wherein the circumferential groove is formed such that a cross-sectional area of the circumferential groove cut in a tire radial direction periodically increases and decreases along the tire circumferential direction.   The vehicle tire according to claim 4, wherein a groove wall of the circumferential groove meanders.   The vehicle tire according to claim 1, wherein a plurality of the circumferential grooves are formed on the tread surface.   7. The cross-sectional shape of the groove wall protrusion cut along the groove bottom and the cross-sectional shape of the groove bottom protrusion cut along the groove wall are triangular. Tires for vehicles.   The groove wall protrusion and the groove bottom protrusion are formed so that the protrusion height H is 0.2 mm or less, the width W of the root portion is 0.3 mm or less, and the pitch P is 1 to 5 times the width W. The vehicle tire according to any one of claims 1 to 7, wherein the vehicle tire is formed.

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