JP4149034B2 - Tires for vehicles - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a vehicle tire, and more specifically to a snow tire (studless tire).
[0002]
[Prior art]
Since spike tires have pollution such as dust and noise, various developments of snow tires (studless tires) have been made in place of the spike tires.
For example, in Japanese Patent Laid-Open No. 2-128907, “a block in which at least five block rows are provided in the tread portion and at least one sipe directed in a substantially fixed direction is provided in each block of each block row. In a vehicle snow tire having a pattern,
The snow tire for a vehicle in which the sipe of each block row gradually increases from the block row located at the outermost portion of the tread portion toward the block row located at the center portion of the tread portion, with respect to the tire equatorial plane. . ”Has been proposed (conventional example 1).
[0003]
In JP-A-2-175302, “at least two circumferential main grooves formed in the tread portion and extending in the tire circumferential direction, lateral main grooves extending between these circumferential main grooves, and Three or more block rows are partitioned by a circumferential main groove extending from the circumferential main groove located on the outermost side in the tire width direction to the edge on the tread portion side, and a plurality of blocks are provided in each block of these block rows. A pneumatic tire with a sipe
A pneumatic tire provided with three or more acute angle protrusions spaced from each other in the tire circumferential direction at at least one edge of each block in the tire width direction. ”Has been proposed (conventional example 2).
[0004]
[Problems to be solved by the invention]
Although the conventional examples 1 and 2 described above are useful as they are, they have the following problems.
The conventional example 1 expects a large traction force by having a large intersection angle with the sipe formed on the center block where the tire encroaching force in ice and snow is the largest, with respect to the tire equatorial plane. The pair of left and right circumferential main grooves that divide the center block are substantially straight, so that the traction force due to the main groove side edge (block side edge) is difficult to achieve. Although there is little, there is a problem that sipe wear becomes severe.
[0005]
In the conventional example 2, three or more acute angle protrusions are provided on the side edges of the center block and the side block, and the edge of the acute angle protrusion expects traction force with frictional force against the snowy and snowy road surface. However, there is a problem that it is not so effective.
Therefore, the present invention provides a vehicle tire having a tread portion of a block pattern, by devising a groove configuration of a pair of left and right center main grooves and a pair of left and right side main grooves, thereby providing an ice and snow road surface (including a new snow road). It is an object of the present invention to provide a vehicle tire that sufficiently secures the traction of the vehicle and secures a gripping force against a side slip of the vehicle.
[0006]
[Means for Solving the Problems]
The present invention takes the following technical means in order to achieve the above-mentioned object in a vehicle tire having a tread portion of a block pattern.
That is, the vehicle tire (particularly studless tire) according to the present invention includes a pair of left and right center main grooves that are arranged at intervals in the width direction of the tread portion and extend in the tire circumferential direction, and the center main grooves. And a pair of left and right side main grooves extending in the circumferential direction of the tire and arranged in the width direction outward of the tread portion of the tire, and the left and right pair of center main grooves and the left and right pair of side main grooves Each of them is formed in zigzag grooves that alternate between left and right in the tire circumferential direction with a fold angle with respect to the equator line, and the fold angle of the left and right pair of center main grooves and the fold angle of the left and right pair of side main grooves are the former Is set to be large and the latter is set to be small , a center block is formed between the pair of left and right center main grooves, and a side block is formed between the center main groove and the side main groove. Formed and before The center block and the side block are composed of two pairs adjacent in the circumferential direction by a lateral groove having a diagonal component, and the lateral groove of the side block has an opening width with respect to the side main groove. It is characterized by being set larger than the opening width for.
[0007]
By adopting such a configuration, the contact pressure distribution of the tread portion of the tire is the highest in the central portion (center region) of the tread portion, and the biting force on the tire into the snowy and snowy road is in that region. Become the largest. And, by forming the center main groove in zigzag grooves alternately left and right , and by increasing the bending angle, the traction force by the side edge of the center main groove, that is, the block side edge is secured, while the side main groove is Since the zigzag grooves are alternately left and right and the folding angle is small, the traction force is assisted at the block side edge and the side slip resistance (grip force) is increased.
[0008]
In addition, by adopting such a configuration, the traction force is enhanced by the edge action by the lateral grooves of two pairs of center blocks and side blocks adjacent in the circumferential direction, and the lateral grooves of the side blocks are the side main grooves. Since the opening width with respect to is set large, the snow drainage becomes good.
Further, in the vehicle tire according to the present invention, a shoulder block is formed to protrude outward in the width direction of the side main groove in the tread portion, and the center block, the side block, and the shoulder block are respectively Sipe having linear elements that are straight on the ground contact surface is formed, and the straight lines in the linear elements of the sipe are formed so that the crossing angles with respect to the tire width direction are different from each other. To do. Here, “each” means “each of the center block, side block, and shoulder block”, and “different angles of intersection” means the sipes formed on the center block, side block, and shoulder block. This means that the crossing angles on the straight lines are different from each other.
[0009]
By adopting such a configuration, in addition to the above-mentioned action, the traction force on the snowy road by the sipe edge is improved, and the traction force is not borne by the sipe edge. It becomes.
Preferably, each intersection angle of the sipe is made smaller in the order of the center block, the side block, and the shoulder block.
Each of the sipe is formed to have a corrugated element together with the linear element in the sipe longitudinal direction, and the linear element is open to the main groove and the corrugated element is closed on the grounding surface of each block. It is recommended that open and close are alternately arranged in the circumferential direction on one ground plane.
[0010]
Also, a vehicle tire according to the present invention, ground plane side edge of the center block and the side blocks, by being bordered on one sawtooth in the tire circumferential direction on the side facing to the main groove, pieces sawtooth The edging enhances the traction force and improves the grip for skidding on icy and snowy roads.
Furthermore, the shoulder block is divided in the width direction of the tread portion by narrow grooves extending in the tire circumferential direction, and the shoulder blocks are arranged in the circumferential direction via the lateral grooves. It is desirable that the inner side of the tread portion is small and the outer side of the tread portion is set large, and the narrow grooves extending in the tire circumferential direction have a zigzag shape alternately left and right in the tire circumferential direction, It is desirable that the contact surface side edge of the inner shoulder block divided by the narrow groove is edged in a single sawtooth shape in the tire circumferential direction on the side facing the side main groove.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows a part of a tread portion 2 of a radial pneumatic tire 1 in a vehicle tire, for example, a studless (snow tire), and has a tread portion 2 of a block pattern.
The tread portion 2 is divided in the tread width T direction by a pair of left and right center main grooves 3L and 3R and a pair of left and right side main grooves 4L and 4R, and an equator line (surface) between the pair of left and right center main grooves 3L and 3R. ) A center block 5 is formed on the XX so as to protrude, and a pair of left and right side blocks 6L, 6R are formed between the center main grooves 3L, 3R and the side main grooves 4L, 4R. In addition, a pair of left and right shoulder blocks 7L, 7R are formed to protrude outward in the width direction of the tread portion 2 of the side main grooves 4L, 4R.
[0012]
The pair of left and right center main grooves 3L and 3R are arranged with a gap in the width direction of the tread portion 2 and extend in the tire circumferential direction, and more specifically, a folding angle θ with respect to the equator line XX. And are formed in zigzag grooves that are alternately left and right in the tire circumferential direction.
The pair of left and right side main grooves 4L and 4R are disposed with a space outward in the width direction of the tread portion 2 of the center main grooves 3L and 3R, and extend in the tire circumferential direction. The zigzag grooves are alternately formed on the left and right sides in the tire circumferential direction with a folding angle θ1 with respect to the equator line XX.
[0013]
Further, the bending angle θ of the pair of left and right center main grooves 3L and 3R and the bending angle θ1 of the pair of left and right side main grooves 4L and 4R are set such that the former θ is large and the latter θ is small. Specifically, by setting 3 ° <θ1 <θ <30 °, traction on snow and ice is improved.
As shown in FIG. 2, the sipe 8, 9L, 9R, which has different intersection angles α1, α2, α3 with respect to the tire axial direction as shown in FIG. 2 is provided on each of the contact surfaces of the center block 5, the side blocks 6L, 6R, and the shoulder blocks 7L, 7R. 10L, 10R are formed, and the intersection angles α1, α2, α3 of the sipes 8, 9L, 9R, 10L, 10R are made smaller in the order of the center block 5, the side blocks 6L, 6R, and the shoulder blocks 7L, 7R.
[0014]
Specifically, the intersection angle α1 of the center block is maximum at 40 °, and the intersection angle α3 of the shoulder block is minimum.
The sipe 8, 9L, 9R, 10L, 10R is formed to have a linear element and a corrugated element in the sipe longitudinal direction as shown in FIG. The elements are open with respect to the center and side main grooves 3 and 4, the corrugated elements are closed, and the open and close are alternately arranged in the circumferential direction on one ground plane.
[0015]
Further, the center block 5 and the side blocks 6L and 6R are configured in two pairs adjacent in the circumferential direction by lateral grooves 11 and 12 having diagonal components, and the lateral grooves 12 of the side blocks 6L and 6R are formed by side mains. The opening width A for the grooves 4L and 4R is set larger than the opening width B for the center main grooves 3L and 3R.
The lateral groove 11 of the center block 5 and the lateral groove 12 of the side block 6 (6L, 6R) have two folds 11A, 12A in the tread width direction, and the grooves 11, 12 are components in an oblique direction. In combination with the above, the traction by the groove side edge (block side edge) and the grip force against side slip are improved, thereby ensuring the running performance on icy and snowy roads. In addition, about the horizontal groove 11, the opening width of the both sides of the diagonal direction component is each set large.
[0016]
Further, a single sawtooth in the tire circumferential direction on the side facing the main grooves 3 (3L, 3R), 4 (4L, 4R) of the center block 5, the side block 6 (6L, 6R) and the shoulder block 7 (7L, 7R) In FIG. 2, the edge portion 13 is represented by a symbol representing the shoulder block 7, and the protrusion amount β of the edge portion 13 is 0.5 to 2.5 mm. In addition, the pitch P is set to 2.0 to 6.0 mm, and the directionality of the edge portion 13 is alternately formed in the circumferential direction with the opposite direction in the circumferential direction. The edge effect is increased.
[0017]
Further, in FIG. 2, the shoulder block 7 (7 </ b> L, 7 </ b> R) is divided in the width direction of the tread portion 2 by a narrow groove 14 extending in the tire circumferential direction, and the shoulder block 7 is circumferentially interposed through the lateral groove 15. The width of the lateral groove 15 is set so that the inner side of the tread portion 2 is small as indicated by the symbol C, and the outer width of the tread portion 2 is large as indicated by the symbol D.
The narrow groove 14 has a zigzag shape alternately left and right in the tire circumferential direction, and the side edge of the inner shoulder block 10 divided by the narrow groove 14 is on the side facing the side main groove 4. By using the edge portion 16 edged in a single sawtooth shape (wave shape) in the tire circumferential direction, the traction and the skid grip force are enhanced, and the turning performance is improved.
[0018]
【The invention's effect】
As described above in detail, according to the present invention, it is possible to provide a tire capable of improving the traction force on an icy and snowy road and the grip force against skidding.
[Brief description of the drawings]
FIG. 1 is a plan view showing a partially expanded tread portion of a tire according to the present invention.
2 is a partially enlarged plan view of FIG. 1. FIG.
[Explanation of symbols]
1 tire
2 Tread 3L, 3R Center main groove 4L, 4R Side main groove
5 Center block 6L, 6R Side block 7L, 7R Shoulder block

Claims (7)

Met vehicle tire having a tread portion of the block pattern,
A pair of left and right center main grooves arranged in the width direction of the tread portion and extending in the tire circumferential direction;
A pair of left and right side main grooves arranged in the width direction of the tread portion of the center main groove with an interval and extending in the tire circumferential direction,
Each of the pair of left and right center main grooves and the pair of left and right side main grooves is formed in zigzag grooves alternately left and right in the tire circumferential direction with a fold angle with respect to the equator line,
The bending angle of the pair of left and right center main grooves and the bending angle of the pair of left and right side main grooves are set such that the former is large and the latter is small.
A center block bulges between the pair of left and right center main grooves,
A side block is formed to protrude between the center main groove and the side main groove,
The center block and the side block are composed of two pairs adjacent in the circumferential direction by lateral grooves having diagonal components,
The lateral groove of the side block is set to have an opening width with respect to the side main groove larger than an opening width with respect to the center main groove. A shoulder block is formed to protrude outward in the width direction of the side main groove in the tread portion,
The center block, the side block, and the shoulder block are each formed with a sipe having a linear element that is a straight line on the ground plane,
The vehicle tire according to claim 1, wherein the straight lines in the linear elements of the sipe are formed so as to have different angles with respect to the tire width direction. The vehicle tire according to claim 2, wherein each intersection angle of the sipes is made smaller in the order of the center block, the side block, and the shoulder block. Each of the sipe is formed with a wave element together with the linear element in the sipe longitudinal direction,
4. The linear element is open to the main groove and the corrugated element is closed on the ground surface of each block, and the open and close are alternately arranged in the circumferential direction on one ground surface. The vehicle tire described in 1. The vehicle according to any one of claims 2 to 4, wherein the edges of the ground contact surfaces of the center block and the side block are edged in a single sawtooth shape in the tire circumferential direction on the side facing the main groove. Tires. The shoulder block is divided in the width direction of the tread portion by narrow grooves extending in the tire circumferential direction,
The shoulder blocks are arranged in a circumferential direction through a lateral groove,
The vehicular tire according to any one of claims 2 to 5, wherein a width of the lateral groove is set so that an inner side of the tread portion is small and an outer side of the tread portion is large . The narrow groove extending in the tire circumferential direction has a zigzag shape alternating between left and right in the tire circumferential direction,
The side edge of the inner shoulder block divided by the narrow groove is edged in a single sawtooth shape in the tire circumferential direction on the side facing the side main groove.
Vehicle tire according to 請 Motomeko 6.

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