JP5930586B2 - Pneumatic tire - Google Patents

Description

  The present invention relates to a pneumatic tire, particularly a pneumatic tire for a passenger car.

  BACKGROUND ART Conventionally, a pneumatic tire that exhibits sufficient braking performance with an edge effect on wet road surfaces and dry road surfaces is known (for example, Patent Document 1).

  In Patent Document 1, a plurality of circumferential grooves and lug grooves are formed in a tread to form a rib-like land portion extending in the tire circumferential direction and a plurality of block-like land portions adjacent to the outer side in the tire width direction of the rib-like land portion. The block-shaped land portion is deformed and the deformation of the block-shaped land portion during the braking (turning up of the edge portion) is suppressed by the rib-shaped land portion, so that the edge effect of the block-shaped land portion is fully exhibited and the braking performance is ensured.

JP 2010-023549 A

  However, in the tire of Patent Document 1, the land portion closest to the tread center (tire equatorial plane) of the tread is a rib-like land portion having high tire circumferential rigidity (low followability to the contact surface). Therefore, the wear of the land portion (rib-shaped land portion) closest to the tread center tends to be accelerated compared to other land portions.

  Moreover, since the lug groove which divides a several block-shaped land part is connected with the circumferential groove formed in the tire width direction outer side of a block-shaped land part, the waste_water | drain which flows through a circumferential groove | channel is provided in a tread. There is a tendency that turbulent flow is easily generated at the connecting portion of the lug groove, and the drainage tends to be lowered.

  An object of the present invention is to provide a pneumatic tire that suppresses wear of a tread center portion and improves drainage while suppressing deformation of a land portion during braking and when a lateral force is generated.

The pneumatic tire according to claim 1 is formed on the tire equatorial plane of the tread, and extends in the tire circumferential direction, and the tire circumferential direction of the first circumferential main groove of the tread. A pair formed on both sides and extending along the tire circumferential direction, formed between the first circumferential main groove and the second circumferential main groove of the tread, A first rib-like land portion extending continuously in the tire circumferential direction is defined between the second circumferential main groove and the groove walls are in contact with each other when the tread is grounded and compressed and deformed. A plurality of narrow grooves are formed between the first circumferential main grooves and the first narrow grooves of the tread at intervals in the tire circumferential direction, and extend in a direction intersecting the tire circumferential direction. The first circumferential main groove and the first narrow groove are connected, and the first rib-shaped land portion is connected to the first circumferential groove. An inclined groove that partitions a plurality of blocks shaped land portion which is wider than the first rib-like land portions adjacent to each other via a narrow groove, the end is opened in said first narrow groove, the other end the A first sipe that opens into the inclined groove, and a plurality of the first rib-shaped land portions are formed on the tread side of the first rib-shaped land portion at intervals in the tire circumferential direction. A second sipe extending continuously from the one end side to the other end side in the direction intersecting the tire circumferential direction and arranged along the same curve as the first sipe is provided .

In the pneumatic tire according to claim 1, when the tread comes into contact with the ground and compressively deforms, the groove walls of the first narrow grooves are in contact with each other, that is, the wall surface of the first rib-shaped land portion and the wall surface of the block-shaped land portion are in contact with each other. The first rib-like land portion and the block-like land portion come to support each other in contact with each other. For this reason, deformation of the block-shaped land portion in the tire circumferential direction during braking is suppressed by the support of the first rib-shaped land portion. As a result, the turning-up of the edge portion on the inclined groove side of the block-shaped land portion during braking is suppressed, and braking performance is ensured.
On the other hand, since the deformation in the tire width direction of the block-like land portion during turning is suppressed by the support of the first rib-like land portion, turning performance is ensured.

  Moreover, in the said pneumatic tire, since the land part nearest to the tire equator surface of a tread is made into a block-like land part, the land part nearest to the tire equator surface of a tread is made into the 1st rib-like land part, for example. Compared to the tread, the tire circumferential rigidity of the land closest to the tread tire equatorial plane is reduced, that is, the followability to the contact surface is improved. Part) is suppressed. Thereby, wear of the tread center portion is suppressed.

And in the said pneumatic tire, the 1st rib-shaped land part continuously extended in a tire circumferential direction is formed in the tire equatorial plane side (tire width direction inner side) of the 2nd circumferential direction main groove of a tread. Thus, for example, turbulent flow is less likely to occur in the drainage flowing through the second circumferential main groove, and drainage performance is improved, as compared with the case where the groove is connected to the second circumferential main groove from the tire equatorial plane side. From the above, according to the pneumatic tire, it is possible to suppress wear of the tread center portion and improve drainage while suppressing deformation of the land portion during braking and when a lateral force is generated.
Moreover, in the pneumatic tire of Claim 1, since several 2nd sipe is formed in the tread side of the 1st rib-shaped land part, drainage property improves. Furthermore, by forming the second sipe, the rigidity in the tire circumferential direction of the first rib-shaped land portion is reduced as compared with, for example, the case where the second sipe is not formed in the first rib-shaped land portion. That is, since the followability of the first rib-like land portion with respect to the ground contact surface is improved, wear of the first rib-like land portion is suppressed.

The pneumatic tire according to claim 2 is the pneumatic tire according to claim 1, wherein the first sipes are curved so as to pass through a central portion of the block-shaped land portion, and are spaced in the tire circumferential direction. Are formed.

The pneumatic tire according to claim 3 is the pneumatic tire according to claim 1 or 2 , wherein the pneumatic tire is formed on an outer side in the tire width direction of the second circumferential main groove of the tread, and the second circumferential main groove. And a second narrow groove that defines a second rib-like land portion extending continuously in the tire circumferential direction between the second circumferential main groove and the second circumferential main groove.

In the pneumatic tire according to claim 3 , the second rib-like land portion continuously extending in the tire circumferential direction on the opposite side (tire width direction outer side) of the second circumferential main groove of the tread to the tire equatorial plane side. Therefore, for example, compared to the case where the groove is connected to the second circumferential main groove from the opposite side to the tire equatorial plane side, the drainage flowing through the second circumferential main groove is disturbed. The flow is difficult to occur and drainage is improved. In particular, in the pneumatic tire, since the first rib-shaped land portion and the second rib-shaped land portion are formed on both sides in the tire width direction of the second circumferential main groove, the second circumferential main groove The wastewater flowing through the turbulent flow is less likely to occur, and the drainage performance is further improved.

A pneumatic tire according to a fourth aspect is the pneumatic tire according to the third aspect , wherein a plurality of pneumatic tires are provided in an outer land portion continuous in a tire circumferential direction defined outside the second narrow groove of the tread in a tire width direction. A widthwise groove is formed, extends in the tire width direction, and ends in the tire width direction and terminates in the outer land portion.

In the pneumatic tire according to claim 4 , since the end portion of the width direction groove on the inner side in the tire width direction terminates in the outer land portion, that is, the outer land portion is not divided by the width direction groove. Becomes difficult to deform in the tire circumferential direction and the tire width direction. Thereby, the deformation | transformation of the tire circumferential direction at the time of the braking of an outer land part and the deformation | transformation of the tire width direction at the time of turning are suppressed.

  As described above, according to the pneumatic tire of the present invention, it is possible to suppress wear of the tread center portion and improve drainage while suppressing deformation of the land portion during braking and when a lateral force is generated.

It is a top view of the tread of the pneumatic tire concerning one embodiment of the present invention.

  Hereinafter, an embodiment of a pneumatic tire according to the present invention will be described with reference to the drawings. In addition, the arrow W direction in a figure has shown the tire width direction.

  FIG. 1 shows a plan view of a pneumatic tire 10 (hereinafter simply referred to as “tire 10”) according to a first embodiment of the present invention. In addition, the internal structure of the tire 10 can use the thing similar to the internal structure of a conventionally well-known pneumatic tire. Therefore, the description of the internal structure of the tire 10 is omitted.

  As shown in FIG. 1, the tread 12 of the tire 10 is formed with a linear first circumferential main groove 14 that extends along the tire circumferential direction on the tire equatorial plane CL, and the first circumferential main groove 14. The linear second circumferential main grooves 16 extending along the tire circumferential direction are formed on both outer sides in the tire width direction.

  Further, the tread 12 is formed with a first narrow groove 18 extending linearly along the tire circumferential direction between the first circumferential main groove 14 and the second circumferential main groove 16, and the second circumferential main groove A second narrow groove 20 extending linearly along the tire circumferential direction is formed on the outer side of the groove 16 in the tire width direction, specifically, between the second circumferential main groove 16 and a ground contact end 12E described later. .

  As shown in FIG. 1, the tread 12 has a ground contact end 12 </ b> E in which a pneumatic tire 10 is mounted on a standard rim defined in JATMA YEAR BOOK (2011 edition, Japan Automobile Tire Association Standard), Filled with 100% of the air pressure (maximum air pressure) corresponding to the maximum load capacity (bold load in the internal pressure-load capacity correspondence table) for the applicable size and ply rating, and the outermost in the tire width direction when the maximum load capacity is applied Refers to the grounding part. When the TRA standard or ETRTO standard is applied at the place of use or manufacturing, the respective standards are followed.

  The tread 12 includes a first circumferential main groove 14 and a first narrow groove 18 extending between the first circumferential main groove 14 and the first narrow groove 18 in a direction intersecting the tire circumferential direction. A plurality of inclined grooves 22 to be connected are formed at intervals in the tire circumferential direction. In the present embodiment, the inclination directions of the inclined grooves 22 formed on both sides of the tire equatorial plane CL are the same direction (in the illustrated state of FIG. 1, the inclination direction is from the upper left to the lower right). .

  The first circumferential main groove 14, the second circumferential main groove 16, the inclined groove 22, and the width direction groove 38, which will be described later, are closed even when the tread 12 contacts the ground and the ribs and blocks are compressed and deformed. The groove width is set so that there is no.

  As shown in FIG. 1, the tread 12 is formed with a plurality of block-like land portions 24 partitioned by the first circumferential main groove 14, the first narrow groove 18, and the inclined groove 22. These block-like land portions 24 constitute block-like land portion rows 25 in the tire circumferential direction.

  Further, the tread 12 is formed with a rib-like land portion 26 continuously extending along the tire circumferential direction defined by the first narrow groove 18 and the second circumferential main groove 16. The rib-shaped land portion 26 is adjacent to the block-shaped land portion row 25 through the first narrow groove 18.

  Further, the tread 12 is formed with a rib-like land portion 28 that continuously extends along the tire circumferential direction defined by the second circumferential main groove 16 and the second narrow groove 20. The rib-shaped land portion 28 is adjacent to the rib-shaped land portion 26 via the second circumferential main groove 16.

  The first narrow groove 18 has a narrower groove width than the first circumferential main groove 14 and the second circumferential main groove 16, and the tread 12 contacts the ground, and the rib-shaped land portion 26 and the block-shaped land portion 24 are respectively compressed and deformed. In this case, the wall surface 26A of the rib-like land portion 26 that is the groove wall on the outer side in the tire width direction of the first narrow groove 18 and the wall surface 24A of the block-like land portion 24 that is the groove wall on the inner side in the tire width direction are in contact with each other. Thus, the groove width is set. The first narrow groove 18 of the present embodiment has a substantially constant groove width from the groove bottom to the groove opening portion on the tread surface side. In the present embodiment, the groove depth of the first narrow groove 18 is shallower than the groove depths of the first circumferential main groove 14 and the second circumferential main groove 16.

  As shown in FIG. 1, the tread surface side of the block-shaped land portion 24 is curved so as to pass through the central portion of the block-shaped land portion 24 from the wall surface 24A on the first narrow groove 18 side toward the wall surface 24B on the inclined groove 22 side. A first sipe 30 is formed. The first sipe 30 has one end opened in the first narrow groove 18 and the other end opened in the inclined groove 22.

  On the tread surface side of the rib-shaped land portion 26, second sipes 32 extending in a direction intersecting the tire circumferential direction from the second circumferential main groove 16 toward the first narrow groove 18 are spaced at regular intervals in the tire circumferential direction. A plurality are formed. The second sipe 32 has one end opened in the second circumferential main groove 16 and the other end opened in the first narrow groove 18.

  On the tread surface side of the rib-shaped land portion 28, third sipes 34 extending in a direction intersecting the tire circumferential direction from the second narrow groove 20 toward the second circumferential main groove 16 are spaced at regular intervals in the tire circumferential direction. A plurality are formed. The third sipe 34 has one end opened to the second narrow groove 20 and the other end opened to the second circumferential main groove 16.

The sipes 30, 32, and 34 are closed at the time of grounding so that the groove width becomes zero.
The sipes 30, 32, and 34 are arranged along the same curve as shown in FIG.

  An outer land portion 36 that is continuous in the tire circumferential direction is defined in the tread 12 outside the second narrow groove 20 in the tire width direction. The outer land portion 36 extends while smoothly curving in the tire width direction, and a plurality of width direction grooves 38 are formed at regular intervals in the tire circumferential direction, with end portions 38A on the inner side in the tire width direction terminating in the outer land portion 36. Has been.

  The second narrow groove 20 is narrower than the first circumferential main groove 14 and the second circumferential main groove 16 in the same manner as the first narrow groove 18, and the tread 12 contacts the rib-like land portion 28 and the outside. When the land portions 36 are respectively compressed and deformed, the wall surface 28A of the rib-like land portion 28 that is the groove wall on the inner side in the tire width direction of the second narrow groove 18 and the outer land portion 36 that is the groove wall on the outer side in the tire width direction. The groove width is set so that the wall surface 36A contacts. The second narrow groove 20 of the present embodiment has a substantially constant groove width from the groove bottom to the groove opening portion on the tread surface side. In the present embodiment, the groove depth of the second narrow groove 20 is shallower than the groove depths of the first circumferential main groove 14 and the second circumferential main groove 16.

Next, the operation of the tire 10 will be described.
In the tire 10, when the tread 12 is grounded and compressed and deformed, the groove walls of the first narrow grooves 18 are in contact with each other, that is, the wall surface 26 </ b> A of the rib-like land portion 26 and the wall surface 24 </ b> A of the block-like land portion 24 are in contact. The rib-like land portion 26 and the block-like land portion 24 come to support each other. Thereby, deformation of the block-shaped land portion 24 in the tire circumferential direction during braking is suppressed by the support of the rib-shaped land portion 26. As a result, the turning-up of the edge portion on the inclined groove 22 side of the block-shaped land portion 24 during braking is suppressed, and braking performance is ensured.
On the other hand, since the deformation in the tire width direction of the block-like land portion 24 during turning is suppressed by the support of the rib-like land portion 26, turning performance is ensured.

Further, in the tire 10, since the land portion closest to the tire equatorial plane CL of the tread 12 is the block-shaped land portion 24 (block-shaped land portion row 25), for example, the land closest to the tire equatorial plane CL of the tread 12 is used. Compared with a rib-like land portion that continuously extends in the tire circumferential direction, the rigidity in the tire circumferential direction of the land portion closest to the tire equatorial plane CL of the tread 12 is reduced, that is, the followability to the ground contact surface is reduced. In order to improve, the wear of the land part closest to the tire equatorial plane CL of the tread 12 is suppressed. That is, wear of the tread center portion 11 is suppressed.
The tread center portion 11 referred to here indicates a portion between the pair of second circumferential main grooves 16 including the second circumferential main grooves 16.

  And since the rib-like land part 26 is formed in the tire equatorial plane CL side (tire width direction inner side) of the 2nd circumferential direction main groove 16 of the tread 12, for example, a tire equator to the 2nd circumferential direction main groove 16 Compared with the case where the groove is connected from the surface CL side, turbulent flow is less likely to occur in the drainage flowing through the second circumferential main groove 16, and drainage performance is improved.

  Moreover, since the rib-like land portion 28 is formed on the opposite side (tire width direction outer side) of the second circumferential main groove 16 of the tread 12 with respect to the tire equatorial plane CL side, for example, the second circumferential main Compared with the case where the groove is connected to the groove 16 from the opposite side to the tire equatorial plane CL side, turbulent flow is less likely to occur in the drainage flowing through the second circumferential main groove 16, and drainage performance is improved.

  In particular, in the tire 10, the rib-like land portions 26 and the rib-like land portions 28 are formed on both sides in the tire width direction of the second circumferential main groove 16, so that the drainage flowing through the second circumferential main groove 16 is further disturbed. The flow is difficult to occur, and drainage is further improved.

  From the above, according to the tire 10, wear of the tread center portion 11 can be suppressed and drainage performance can be improved while suppressing deformation of the land portion during braking and occurrence of lateral force.

Further, in the tire 10, the end 38 </ b> A on the inner side in the tire width direction of the width direction groove 38 terminates in the outer land portion 36, that is, the outer land portion 36 is not divided by the width direction groove 38. The outer land portion 36 is not easily deformed in the tire circumferential direction and the tire width direction. Thereby, the deformation | transformation of the tire circumferential direction at the time of the braking of the outer side land part 36 and the deformation | transformation of the tire width direction at the time of turning are suppressed.
When the tread 12 comes into contact with the ground and compressively deforms, the groove walls of the second narrow grooves 20 come into contact with each other, that is, the wall surface 28A of the rib-like land portion 28 and the wall surface 36A of the outer land portion 36 come into contact with each other. The land portion 28 and the outer land portion 36 support each other. Thereby, since the deformation | transformation of the tire width direction of the outer side land part 36 and the rib-shaped land part 28 at the time of turning is suppressed by mutual support, turning performance is ensured.

  In particular, when turning, the input to the outer land portion 36 on the outer side in the turning radius direction of the vehicle is the largest, and this outer land portion 36 tends to be deformed inward in the tire width direction (tire equatorial plane CL side). Since the rib-like land portion 28 adjacent to the inner side in the tire width direction of the land portion 36 suppresses the deformation of the outer land portion 36 toward the inner side in the tire width direction, the turning performance can be improved more effectively.

In the tire 10, since the sipe 30, 32, and 34 are formed in each land part 24, 26, and 28, drainage property improves.
In particular, since the first sipe 30 has one end opened in the first narrow groove 18 and the other end opened in the inclined groove 22, the sucked water can be drained into the first narrow groove 18 and the inclined groove 22. Since the two sipes 32 have one end opened in the second circumferential main groove 16 and the other end opened in the first narrow groove 18, the sucked water is drawn into the second circumferential main groove 16 and the first narrow groove 18. Since the third sipe 34 has one end opened in the second narrow groove 20 and the other end opened in the second circumferential main groove 16, the third sipe 34 can suck the sucked water into the second narrow groove 20 and the second narrow groove 20. The circumferential main groove 16 can be drained. Thereby, the drainage of the tire 10 can be improved effectively.

Further, since the second sipe 32 is formed in the rib-like land portion 26, the rigidity in the tire circumferential direction of the rib-like land portion 26 is reduced, that is, the followability to the ground contact surface is improved, and the rib-like land portion 26 is improved. Wear is suppressed. Further, since the third sipe 34 is formed in the rib-shaped land portion 28, the rigidity in the tire circumferential direction of the rib-shaped land portion 28 is reduced, that is, the followability to the ground contact surface is improved, and the rib-shaped land portion 28 is improved. Wear is suppressed. Thereby, generation | occurrence | production of the partial wear of the tire 10 is suppressed.

  The embodiments of the present invention have been described above with reference to the embodiments. However, these embodiments are merely examples, and various modifications can be made without departing from the scope of the invention. It goes without saying that the scope of rights of the present invention is not limited to these embodiments.

10 Pneumatic tire 12 Tread 14 First circumferential main groove (first circumferential main groove)
16 Second circumferential main groove (second circumferential main groove)
18 First narrow groove (first narrow groove)
20 Second narrow groove (second narrow groove)
22 inclined groove 24 block-like land portion 24A wall surface (wall surface of first narrow groove)
26 Rib Land (First Rib Land)
26A wall surface (wall surface of the first narrow groove)
28 Rib Land (Second Rib Land)
32 Second Sipe (Sipe)
36 Outer land portion 38 Width direction groove 38A End portion (End portion on the inner side in the tire width direction of the width direction groove)
CL Tire equatorial plane W Tire width direction

Claims (4)

A first circumferential main groove formed on the tire equatorial plane of the tread and extending along the tire circumferential direction;
A pair of second circumferential main grooves formed on both sides of the first circumferential main groove of the tread in the tire width direction and extending along the tire circumferential direction;
First tread formed between the first circumferential main groove and the second circumferential main groove of the tread and extending continuously in the tire circumferential direction between the second circumferential main groove. A first narrow groove that divides a rib-like land portion, and the groove walls come into contact with each other when the tread is grounded and compressed and deformed;
A plurality of tire treads are formed at intervals in the tire circumferential direction between the first circumferential main groove and the first narrow groove of the tread, and extend in a direction intersecting the tire circumferential direction. A circumferential main groove and the first narrow groove are connected to each other and wider than the first rib-shaped land portion adjacent to the first rib-shaped land portion via the first narrow groove . An inclined groove that divides a plurality of block-shaped land portions;
A first sipe having one end opened in the first narrow groove and the other end opened in the inclined groove;
With
A plurality of tire ribs are formed on the tread surface side of the first rib-shaped land portion at intervals in the tire circumferential direction, and from the one end side to the other end side in the width direction of the first rib-shaped land portion with respect to the tire circumferential direction. A pneumatic tire provided with a second sipe extending continuously in the intersecting direction and arranged along the same curve as the first sipe .   2. The pneumatic tire according to claim 1, wherein a plurality of the first sipes are curved so as to pass through a central portion of the block-shaped land portion, and a plurality of the first sipes are formed at intervals in the tire circumferential direction.   Formed on the outer side in the tire width direction of the second circumferential main groove of the tread, the groove width is narrower than the second circumferential main groove, and the tire circumferential direction between the second circumferential main groove and the second circumferential main groove The pneumatic tire according to claim 1, further comprising a second narrow groove defining a second rib-like land portion extending continuously.   A plurality of outer land portions extending in the tire circumferential direction and spaced apart from each other in the tire circumferential direction, which are defined on the outer side in the tire width direction than the second narrow groove of the tread, extend in the tire width direction, and extend in the tire width direction. The pneumatic tire according to claim 3, wherein an inner end portion has a width direction groove that terminates in the outer land portion.

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