JP4926486B2 - Pneumatic tire - Google Patents

Description

  The present invention relates to a pneumatic tire.

In general, as shown in Patent Document 1 below, for example, a pneumatic tire has a plurality of circumferential grooves continuously extending in the tire circumferential direction at intervals in the width direction of the tread tread surface portion. In addition, a plurality of lug grooves that are opened in a pair of circumferential grooves adjacent to each other in the width direction are formed at intervals in the tire circumferential direction.
And in this kind of pneumatic tire, in order to suppress generation | occurrence | production of what is called a hydroplaning phenomenon, there exists a request with respect to improving the drainage performance of a tread tread surface part.
JP 2002-19423 A

However, in the conventional pneumatic tire, when the water accumulated in one circumferential groove of the pair of circumferential grooves is caused to flow toward the front side in the tire rotation direction along with the rotation of the tire, a part thereof is the circumferential groove. The lug groove opens into the lug groove that opens to the other, and the lug groove reaches the other circumferential groove that is open, and the remainder continues to flow toward the front side in the tire rotation direction without entering the lug groove. In this case, the water flow is disturbed at the opening (branching part) of the lug groove in one circumferential groove and the opening part (merging part) of the lug groove in the other circumferential groove. Water sometimes stayed. That is, in the one circumferential groove, when the water passes through the branch portion, the flow rate of water decreases rapidly, or the water flow is disturbed because the branch portion becomes resistant to the flow of water, In the other circumferential groove, the water from the lug groove joins the water originally flowing in this groove, and thus the original water flow may be disturbed at the joining portion.
These were great obstacles in improving drainage performance.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a pneumatic tire capable of improving drainage performance by suppressing disturbance of the water flow in the circumferential groove.

In order to solve the above problems and achieve such an object, in the pneumatic tire of the present invention, a circumferential groove extending continuously in the tire circumferential direction is formed on the tread tread portion of the tire in the width direction of the tread tread portion. A plurality of lug grooves that are opened in a pair of circumferential grooves adjacent to each other in the width direction are formed at intervals in the tire circumferential direction, and the rotation direction is specified. A first rectifying fin that extends along the tire circumferential direction on the front side in the tire rotation direction in the peripheral portion of the circumferential groove at the opening of the lug groove defines the circumferential groove. It is characterized by being arranged so as not to overlap the opening of the lug groove in a state where a gap is provided between the side wall surface and the side wall surface.

  In the present invention, since the first rectifying fin is provided, the peripheral portion of the opening portion of the lug groove in the circumferential groove, that is, the branching portion to the lug groove in one circumferential groove of the pair of circumferential grooves, and the other Even if the water flow is disturbed in at least one of the joining portions of the circumferential groove with the lug groove, this disturbance can be made by passing the water between the side wall surface of the circumferential groove and the first rectifying fin. It becomes possible. Or it becomes possible to prevent this disturbance of the water flow. Therefore, it becomes possible to prevent water from staying in at least one of the branching portion to the lug groove in one circumferential groove and the joining portion with the lug groove in the other circumferential groove, and the drainage performance of the tire is reduced. Can be improved.

  Here, a plurality of the first rectifying fins are arranged at intervals in the width direction of the circumferential groove, and these fins gradually move forward in the rotational direction of the tire from one side to the other side in the width direction of the circumferential groove. Alternatively, the position may be shifted on the rear side.

  In this case, since the plurality of first rectifying fins are provided at intervals in the width direction of the circumferential groove, it is possible to reliably arrange the disturbance of the water flow. In addition, since the plurality of first rectifying fins are provided with their positions shifted as described above, when the water reaches the position where the first rectifying fins are disposed in the process of water flowing in the circumferential groove. In addition, it is possible to prevent the flow from being hindered by a sudden reduction in the cross-sectional area of the water flow, and although the water flow can be adjusted by providing the first rectifying fins, It is possible to prevent the efficiency from decreasing.

  The length of the first rectifying fin in the tire circumferential direction may be shorter than the arrangement pitch of the lug grooves in the tire circumferential direction.

  Furthermore, at least an end of the first rectifying fin on the front side in the rotational direction of the tire may be gradually narrowed from the rear side in the rotational direction toward the front side.

  In this case, since the flow passage cross-sectional area of the water gradually increases toward the front side in the tire rotation direction at the position where the first rectifying fins are disposed in the circumferential groove, the water whose flow is adjusted by the first rectifying fins is smoothly supplied. It becomes possible to feed the circumferential groove toward the front side in the rotational direction.

  Furthermore, the height of the first rectifying fin may be 10% or more and 90% or less of the depth of the circumferential groove, and the width of the first rectifying fin is 5% or more of the width of the circumferential groove. While being 30% or less, it may be 20% or more and 40% or less of the width of the lug groove.

  Further, the lug groove gradually extends toward the front side in the rotational direction of the tire as it goes from the inner side in the width direction to the outer side of the tread surface, and the lug groove extends to the end of the lug groove on the front side in the rotational direction of the tire. The 2nd rectification fin extended along a direction may be arrange | positioned in the state in which the clearance gap was provided between the side wall surfaces which define this lug groove.

  In this case, even when the water flowing in the one circumferential groove collides with the branch portion of the circumferential groove, the flow of water entering the lug groove from the one circumferential groove is disturbed. It is possible to reach the other circumferential groove in a state in which this disturbance is adjusted, and it is possible to smoothly join the water flow that originally flowed in the other circumferential groove. Accordingly, it is possible to suppress the disturbance of the water flow at the portion where the other circumferential groove joins the lug groove, and in combination with the provision of the first rectifying fin, the water flow in the other circumferential groove Disturbance can be prevented more reliably.

  According to this invention, it is possible to improve the drainage performance by suppressing the disturbance of the water flow in the circumferential groove.

Hereinafter, a first embodiment of a pneumatic tire according to the present invention will be described with reference to FIG.
FIG. 1 is a plan view showing a tread tread surface portion 10a of a pneumatic tire 10. A tread tread surface portion 10a has a circumferential groove 11 extending continuously in the tire circumferential direction on the tread tread surface portion 10a whose rotation direction is specified. A plurality of these circumferential grooves 11 are formed at intervals in the width direction, and among these circumferential grooves 11, lug grooves 12 respectively opened in a pair of circumferential grooves 11 adjacent in the width direction of the tread tread surface portion 10a are spaced in the tire circumferential direction. A plurality are formed. The pneumatic tire 10 shown in FIG. 1 rotates so that the tread tread surface portion 10a moves from the lower side to the upper side in FIG. 1, and the upper side in FIG. It is the direction rear side B.

  In the present embodiment, the circumferential groove 11 includes a main circumferential groove 11a formed in each of the left part and the right part across the tire equator CL at the center in the width direction of the tread surface 10a, and these main circumferential grooves. A sub-peripheral groove 11b is formed on the outer side in the width direction of the tread tread portion 10a with respect to 11a, and is narrower than the main peripheral groove 11a. Of these, the main circumferential groove 11a defines a center rib 13 extending over the entire region in the tire circumferential direction on the tire equator CL. In the present embodiment, the center portion of the center rib 13 in the width direction of the tread surface portion 10a is positioned on the tire equator portion CL.

  The lug groove 12 includes a pair of circumferential grooves 11 adjacent to each other in the width direction of the tread tread surface portion 10a, that is, a main circumferential groove 11a in the tread tread surface portion 10a on the left side and the right side of the tire equator CL. Between the sub-circumferential groove 11b, the tread tread surface portion 10a is formed so as to gradually extend toward the front side A in the rotational direction of the tire from the inner side in the width direction toward the outer side. The lug grooves 12 open to the adjacent main circumferential groove 11a and sub circumferential groove 11b, respectively. Thereby, a plurality of land portions 14a defined by the main circumferential groove 11a, the sub circumferential groove 11b, and the lug groove 12 are arranged in the tire circumferential direction between the adjacent main circumferential groove 11a and the sub circumferential groove 11b. A land portion row 14 is formed.

  In the above configuration, when a vehicle equipped with the pneumatic tire 10 travels on a wet road surface, the pneumatic tire 10 rotates so that the tread surface portion 10a moves toward the front side A in the rotational direction. However, at this time, the water accumulated in the main circumferential groove 11a flows toward the front side A in the rotational direction along with the rotation of the tire 10, and part of the water enters the lug groove 12 opened in the main circumferential groove 11a. The lug groove 12 reaches the secondary circumferential groove 11b that is open, while the remainder does not enter the lug groove 12 and continues to flow in the main circumferential groove 11a toward the front side A in the rotational direction. Further, the water accumulated in the sub circumferential groove 11b flows toward the front side A in the rotation direction, and when the water reaches the opening of the lug groove 12, the water from the main circumferential groove 11a merges, and the rotation direction continues with this water. It flows toward the front side A.

  In this manner, the opening of the lug groove 12 in the main circumferential groove 11a is a water flow branching portion 11c that branches the water originally flowing in the main circumferential groove 11a toward the sub circumferential groove 11b, and the sub circumferential groove 11b. The opening of the lug groove 12 is a water flow confluence portion 11d where water from the main circumferential groove 11a merges with the water originally flowing through the sub circumferential groove 11b.

  In the present embodiment, the tire circumferential direction is on the front side A in the rotational direction at each peripheral portion of the branching portion 11c of the main circumferential groove 11a and the joining portion 11d of the sub circumferential groove 11b (the opening of the lug groove 12 in the circumferential groove 11). The first rectifying fins 15 extending along the circumferential direction are arranged in a state where a gap is provided between the first rectifying fins 15 and the side wall surface defining the circumferential groove 11. The illustrated first straightening fin 15 has a rectangular shape in plan view, and its end on the front side A in the rotational direction has a curved surface convex toward the front side A, and the end on the rear side B in the rotational direction has this end. The curved surface is convex toward the rear side B. Further, the first rectifying fins 15 are arranged on the front side A in the rotational direction in all the peripheral portions of the plurality of branch portions 11c and merging portions 11d. Further, the first rectifying fins 15 are disposed on the front side A in the rotational direction in the respective peripheral portions of the branching portion 11c and the joining portion 11d so as not to overlap these 11c and 11d.

A plurality of the first rectifying fins 15 are arranged at intervals in the width direction of the circumferential groove 11, and each of these fins 15 gradually rotates as it goes from one side to the other side in the width direction of the circumferential groove 11. The position is shifted to the front side A or the rear side B. In the illustrated example, three first rectifying fins 15 arranged on the front side A in the rotational direction are provided in the peripheral portion of the branch portion 11c of the main circumferential groove 11a, and these fins 15 are arranged in the tire width direction of the main circumferential groove 11a. As it goes from the outside to the inside, the position is gradually shifted to the front side A in the rotational direction. In addition, two first rectifying fins 15 arranged on the front side A in the rotational direction are provided in the peripheral portion of the confluent portion 11d of the sub circumferential groove 11b, and these first rectifying fins 15 are arranged in the tire width direction of the sub circumferential groove 11b. As it goes from the outside to the inside, the position is gradually shifted to the front side A in the rotational direction.
The first rectifying fins 15 that are arranged on the front side A in the rotational direction of the peripheral portions and are adjacent in the width direction of the circumferential groove 11 are arranged in a state in which at least a part of the side surfaces thereof face each other.
As described above, water can pass between the first rectifying fins 15 and between the first rectifying fins 15 and the side wall surface of the circumferential groove 11.

  Here, the length of the first rectifying fin 15 in the tire circumferential direction is shorter than the arrangement pitch of the lug grooves 12 in the tire circumferential direction. Further, the height of the first rectifying fins 15 is set to 10% or more and 90% or less of the depth of the main circumferential groove 11a. Further, the width of the first rectifying fins 15 is set to 5% to 30% of the width of the main circumferential groove 11a and 20% to 40% of the width of the lug groove 12. For example, when the width of the main circumferential groove 11a is 11 mm, the width of the first rectifying fin 15 is about 1 to 2 mm.

  Further, in the present embodiment, the second rectifying fin 16 extending along the direction in which the lug groove 12 extends is formed at the end of the lug groove 12 on the front side A in the rotational direction, and the side wall surface defining the lug groove 12. Are arranged with a gap between them. The end of the second rectifying fin 16 on the front side A in the rotational direction is disposed so as not to protrude from the side wall surface defining the sub circumferential groove 11b. The second rectifying fins 16 are substantially the same shape and size as the first rectifying fins 15. Further, in the illustrated example, one second rectifying fin 16 is disposed at the end of the lug groove 12 on the front side A in the rotational direction.

  Further, the length of the second rectifying fin 16 in the direction in which the lug groove 12 extends is shorter than the length of the lug groove 12. Further, the height of the second rectifying fins 16 is set to be 10% or more and 90% or less of the depth of the sub circumferential groove 11b.

  As described above, according to the pneumatic tire 10 according to the present embodiment, since the first rectifying fins 15 are provided, the peripheral portion of the opening of the lug groove 12 in the circumferential groove 11, that is, the main circumferential groove 11a. Even if the water flow is disturbed at the branching portion 11c to the lug groove 12 and at the joining portion 11d of the auxiliary circumferential groove 11b with the lug groove 12, the water flows into the side wall surface of the main circumferential groove 11a or the auxiliary circumferential groove 11b and the first rectification. By passing between the fins 15 and between the first rectifying fins 15, this disturbance can be adjusted. Or it becomes possible to prevent this disturbance of the water flow. Therefore, it is possible to prevent water from staying at the branching portion 11c of the main circumferential groove 11a to the lug groove 12 and the joining portion 11d of the auxiliary circumferential groove 11b with the lug groove 12, and the drainage performance of the tire 10 can be prevented. Can be improved.

  In the present embodiment, since the plurality of first rectifying fins 15 are arranged in the circumferential groove 11 at intervals in the width direction, the disturbance of the water flow can be reliably adjusted. In addition, since the plurality of first rectifying fins 15 are provided with their positions shifted as described above, the water reaches the position where the first rectifying fins 15 are disposed in the process of water flowing in the circumferential groove 11. However, when the flow passage cross-sectional area of the water suddenly decreases, it is possible to prevent the flow from being hindered, and the water flow can be adjusted by providing the first rectifying fins 15. The drainage efficiency can be prevented from decreasing.

  Further, since the second rectifying fin 16 is disposed in the lug groove 12 with a gap provided between the side wall surfaces defining the lug groove 12, the water flowing in the main circumferential groove 11a However, even when the flow of water that has entered the lug groove 12 from the main circumferential groove 11a is disturbed by colliding with the branch portion 11c of the main circumferential groove 11a, 11b can be achieved, and the water flow originally flowing in the auxiliary circumferential groove 11b can be smoothly joined. Accordingly, it is possible to suppress the disturbance of the water flow at the joining portion 11d of the sub circumferential groove 11b with the lug groove 12, and in combination with the provision of the first rectifying fins 15, this sub circumferential groove 11b. It is possible to more reliably prevent the water flow from being disturbed.

The technical scope of the present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention.
For example, in the embodiment, in the circumferential groove 11, the first rectifying fins 15 are arranged on the rotation direction front side A in the respective peripheral portions of the branching portion 11c of the main circumferential groove 11a and the joining portion 11d of the sub circumferential groove 11b. You may make it arrange | position to at least one of these. Moreover, although the plurality of first rectifying fins 15 are arranged on the front side A in the rotation direction in each peripheral portion, one may be arranged. Furthermore, although the first rectifying fins 15 are arranged on the front side A in the rotational direction in all the peripheral portions of the plurality of branch portions 11c and the merging portion 11d, they may be arranged in at least one place.

  In the embodiment, the plurality of first rectifying fins 15 arranged on the front side A in the rotation direction in the peripheral portion of the branching portion 11c of the main circumferential groove 11a are moved from the outer side in the tire width direction toward the inner side of the main circumferential groove 11a. Instead of this, the position is shifted to the front side A of the gradually rotating direction. Instead, as shown in FIGS. 2 and 3, the main circumferential groove 11a is gradually moved to the front side A as it goes from the inner side to the outer side in the tire width direction. The position may be shifted, or the position may not be shifted as described above and the width direction may be arranged in parallel, or the tire circumferential direction may be arranged in series. Good.

  Furthermore, in the said embodiment, the several 1st rectification fin 15 arrange | positioned in the rotation direction front side A in the peripheral part of the confluence | merging part 11d of the sub circumferential groove 11b is made to go inside from the tire width direction outer side of the sub circumferential groove 11b. Instead of this, the position is shifted to the front side A of the gradually rotating direction, but instead, the position of the auxiliary circumferential groove 11b may be shifted to the front side A of the gradually rotating direction from the inner side to the outer side in the tire width direction. Alternatively, it may be arranged in parallel in the width direction without shifting the position, or may be arranged in series in the tire circumferential direction.

  Moreover, in the said embodiment, while the edge part of the rotation direction front side A is made into the convex curved shape toward this front side A as the 1st rectification fin 15, the edge part of the rotation direction rear side B is this back side B. In FIG. 3, instead of this, the end portion on the front side A in the rotational direction is formed from the rear side B in the rotational direction, as shown in FIG. A tapered configuration with the width gradually decreasing toward the front side A may be employed. In addition to this configuration, as shown in FIG. You may employ | adopt the structure made into the taper shape by which the width | variety was gradually narrowed as it goes to the rear side B from the front side A.

  In these cases, since the flow passage cross-sectional area of the water gradually increases toward the front side A in the rotational direction at the position where the first rectifying fins 15 are disposed in the circumferential groove 11, the water whose flow is adjusted by the first rectifying fins 15. Can be smoothly fed out toward the front side A in the rotational direction of the circumferential groove 11.

Furthermore, in the said embodiment, although the structure where the one 2nd rectification fin 16 was arrange | positioned in the edge part of the rotation direction front side A in the lug groove 12 was replaced with this, you may arrange | position more than one. For example, as shown in FIG. 2, a plurality of second rectifying fins 16 may be arranged spaced apart from each other in the width direction of the sub circumferential groove 11 b. In this case, the plurality of second rectifying fins 16 may be arranged so as to be gradually shifted to one side or the other side in the width direction of the lug groove 12 in the direction in which the lug groove 12 extends. Or you may arrange | position in parallel in the width direction of the lug groove 12, without arranging a position in this way, and may arrange in series in the direction where the lug groove 12 extends. In FIG. 2, the second rectifying fin 16 disposed near the sub circumferential groove 11 b in the extending direction of the lug groove 12 is disposed on the front side A in the rotation direction, and the second rectifying fin 16 disposed near the main circumferential groove 11 a rotates. It is arranged on the direction rear side B. Moreover, you may arrange | position the 2nd rectifying fin 16 adjacent in the width direction of the lug groove 12 so that at least one part of the side surface may mutually oppose.
Furthermore, the planar view shape of the second rectifying fins 16 may be the other form of the first rectifying fins 15 described above, instead of the embodiment.

  Next, the verification test was implemented about the effect demonstrated above. In this test, the tire size is 205 / 55R16 and the NEG rate is 29%. The pneumatic tires 10, 20, and 30 shown in FIGS. When a conventional tire that does not have the fins 15 and 16 is mounted on a vehicle and the vehicle is driven on a wet road surface having a water depth of 5 mm, when the vehicle cannot travel straight, that is, when the hydroplaning occurs, the traveling speed Was evaluated by index evaluation. The width of the main circumferential groove 11a is about 12 mm, the width of the auxiliary circumferential groove 11b is about 7 mm, the height of the first and second rectifying fins 15 and 16 is about 4 mm, the main circumferential groove 11a, the auxiliary circumferential groove 11b and the lug. The depth of each groove 12 was about 8 mm.

  As a result, assuming that 100 when the conventional tire is mounted is 113 in the pneumatic tire 10 in FIG. 1, 115 in the pneumatic tire 20 in FIG. 2, and 113 in the pneumatic tire 30 in FIG. It was confirmed that the pneumatic tires shown in FIGS. 1 to 3 have improved drainage performance and can suppress the occurrence of the hydroplaning phenomenon.

  It is possible to improve drainage performance by suppressing disturbance of the water flow in the circumferential groove.

In 1st Embodiment which concerns on this invention, it is a top view which shows the tread surface part of a pneumatic tire. In 2nd Embodiment which concerns on this invention, it is a top view which shows the tread surface part of a pneumatic tire. In 3rd Embodiment which concerns on this invention, it is a top view which shows the tread surface part of a pneumatic tire.

Explanation of symbols

10, 20, 30 Pneumatic tire 10a Tread tread portion 11 Circumferential groove 11c Branch portion (opening portion of lug groove)
11d Junction (Lug groove opening)
12 lug grooves 15 first rectifying fins 16 second rectifying fins A rotation direction front side B rotation direction rear side

Claims (7)

A plurality of circumferential grooves continuously extending in the tire circumferential direction are formed in the tread tread portion of the tire at intervals in the width direction of the tread tread portion, and a pair of adjacent grooves in the width direction among these circumferential grooves. A plurality of lug grooves that are open in the circumferential grooves are formed at intervals in the tire circumferential direction, and a pneumatic tire in which a rotational direction is specified,
A gap is provided between the first rectifying fin extending along the tire circumferential direction and the side wall surface defining the circumferential groove on the front side in the tire rotation direction in the peripheral portion of the opening of the lug groove in the circumferential groove. A pneumatic tire characterized by being disposed so as not to overlap with the opening of the lug groove . The pneumatic tire according to claim 1,
A plurality of the first rectifying fins are arranged at intervals in the width direction of the circumferential groove, and these fins gradually move forward or backward in the rotational direction of the tire from one side to the other side in the width direction of the circumferential groove. A pneumatic tire characterized by being shifted in position. In the pneumatic tire according to claim 1 or 2,
The pneumatic tire according to claim 1, wherein a length of the first rectifying fin in the tire circumferential direction is shorter than an arrangement pitch of the lug grooves in the tire circumferential direction. In the pneumatic tire according to any one of claims 1 to 3,
A pneumatic tire characterized in that at least an end of the first rectifying fin on the front side in the rotational direction of the tire gradually decreases in width from the rear side in the rotational direction toward the front side. In the pneumatic tire according to any one of claims 1 to 4,
The pneumatic tire according to claim 1, wherein a height of the first rectifying fin is 10% or more and 90% or less of a depth of the circumferential groove. In the pneumatic tire according to any one of claims 1 to 5,
The pneumatic tire according to claim 1, wherein the width of the first rectifying fin is 5% to 30% of the width of the circumferential groove and 20% to 40% of the width of the lug groove. In the pneumatic tire according to any one of claims 1 to 6,
The lug groove gradually extends toward the front side in the rotational direction of the tire as it goes from the inner side to the outer side in the width direction of the tread surface, and the lug groove extends in the direction in which the lug groove extends at the end of the lug groove on the front side in the rotational direction. A pneumatic tire characterized in that the second rectifying fin extending along the side wall is disposed in a state where a gap is provided between the second rectifying fin and the side wall surface defining the lug groove.

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