JP2018161944A - tire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pneumatic tire having improved snow and ice road performance while maintaining steering stability performance. A tire 1 has a tread surface 4a sandwiched between a first edge 5 and a second edge 6 extending in the circumferential direction of the tire. On the tread surface 4a, a full open sipe 10 extending from the first edge 5 to the second edge 6 and a first semi arranged adjacent to one side of the full open sipe 10 in the tire circumferential direction and extending from the first edge 5. At least an open sipe 11 and a second semi-open sipe 12 arranged adjacent to the other side of the full open sipe 10 in the tire circumferential direction and extending from the second edge 6 are provided. The first semi-open sipe 11 and the second semi-open sipe 12 are pneumatic tires extending in a direction approaching a virtual straight line connecting both ends of the full open sipe 10 toward the interrupted ends 11e and 12e, respectively. [Selection diagram] Fig. 1

Description

  The present invention relates to a tire provided with a plurality of blocks in a tread portion.

  For example, a tire intended for running on snowy and icy roads is provided with a plurality of blocks in the tread portion. A narrow sipe is formed in each block. Such tires increase the snow column shear force and the frictional force against the snow and ice road surface.

  In recent years, it has been demanded to improve running performance on snowy and ice road surfaces. In order to increase the frictional force on ice, it is conceivable to increase the number of sipes. However, such a method has a problem that the rigidity of the block is lowered and the steering stability performance is deteriorated.

JP 2012-224245 A

  The present invention has been devised in view of the above circumstances, and provides a tire that can improve driving performance on snowy and icy roads while maintaining steering stability performance based on improving the arrangement of sipes and the like. The main purpose is to do.

  The present invention is a tire provided with a plurality of blocks in the tread portion, and at least one of the blocks has a tread sandwiched between a first edge and a second edge extending in the tire circumferential direction, A full open sipe extending from the first edge to the second edge, and adjacent to one side in the tire circumferential direction of the full open sipe and extending from the first edge to the full tread. A first semi-open sipe having a discontinuous end that terminates without reaching both the sipe and the second edge; and disposed adjacent to the other side in the tire circumferential direction of the full-open sipe and extending from the second edge, At least a full open sipe and a second semi-open sipe having a break that terminates without reaching the first edge; Each semi-open sipes and the second semi-open sipes extend in a direction approaching the virtual straight towards the broken end of the respective connecting ends of the full-open sipe.

  In the tire according to the present invention, it is preferable that the full open sipe has a zigzag shape having a first apex portion and a second apex portion protruding from the one side and the other side in the tire circumferential direction with respect to the virtual straight line.

  In the tire according to the present invention, the full open sipe includes an inclined element that is inclined with respect to the virtual straight line and connects the first top portion and the second top portion, and the discontinuity of the first semi-open sipe. The end is preferably located within a projection region obtained by projecting the inclined element in the tire circumferential direction.

  In the tire according to the present invention, it is desirable that the discontinuous end of the first semi-open sipe is located 2 to 5 mm apart from the first top.

  In the tire according to the present invention, the full open sipe includes an inclined element that is inclined with respect to the virtual straight line and connects the first top portion and the second top portion, and the discontinuity of the second semi-open sipe. The end is preferably located within a projection region obtained by projecting the inclined element in the tire circumferential direction.

  In the tire according to the present invention, it is preferable that the discontinuous end of the second semi-open sipe is located 2 to 5 mm apart from the second top portion.

  In the tire according to the present invention, the full open sipe includes a second edge-side inclined element extending from the first top portion to the second edge with an inclination opposite to the inclined element, and the first semi-open sipe is It is desirable to incline in the same direction as the second edge side inclined element.

  In the tire according to the present invention, the full open sipe includes a first edge-side inclined element extending from the second top portion to the first edge at an inclination opposite to the inclined element, and the second semi-open sipe is It is desirable to incline in the same direction as the first edge side inclined element.

  In the tire according to the present invention, the full open sipe includes a second edge-side inclined element extending from the first top portion to the second edge with an inclination opposite to the inclined element, and the inclined element and the first It is desirable that the angle between the edge-side inclined element is 110 to 130 degrees, and the angle between the inclined element and the second edge-side inclined element is 110 to 130 degrees.

  In the tire according to the present invention, the first edge is arranged on the outer side in the tire axial direction with respect to the second edge, and the first edge-side inclined element is arranged at the end on the first edge side in the tire axial direction. It is desirable to have an axial portion extending along.

  In the tire according to the present invention, the block includes a first block in which the second edge extends zigzag and a second block in which the second edge extends smoothly, and the first block is the first semi-open. The angle of the sipe with respect to the tire axis direction is 10 to 30 degrees, the angle of the second semi-open sipe with respect to the tire axis direction is 20 to 40 degrees, and the second block is the tire axis of the first semi-open sipe The angle with respect to the direction is preferably 15 to 35 degrees, and the angle with respect to the tire axial direction of the second semi-open sipe is preferably 15 to 35 degrees.

  In the tire of the present invention, the block has a tread sandwiched between a first edge and a second edge extending in the tire circumferential direction. A full open sipe extending from the first edge to the second edge, and adjacent to one side in the tire circumferential direction of the full open sipe and extending from the first edge to the full tread. A first semi-open sipe that terminates without reaching both the sipe and the second edge; and the full-open sipe disposed adjacent to the other side in the tire circumferential direction of the full-open sipe and extending from the second edge; At least a second semi-open sipe that terminates without reaching the first edge is provided. Since the full open sipe, the first semi-open sipe, and the second semi-open sipe can exert a large frictional force, snow and ice road performance is improved. Further, the first semi-open sipe and the second semi-open sipe can suppress a decrease in the rigidity of the block while exhibiting the above-described action.

  Each of the first semi-open sipe and the second semi-open sipe extends in a direction approaching a virtual straight line connecting both ends of the full-open sipe toward the respective cut ends. Thereby, since the rigidity of a block is equalized, the crack which started from each sipe is suppressed. For this reason, since the rigidity reduction of a block is suppressed small, steering stability performance is further maintained.

  Therefore, the tire of the present invention improves snow and ice road performance while maintaining steering stability performance.

It is an expanded view of the tread part of one Embodiment of this invention. It is an expanded view of the block of one Embodiment. It is an expanded view of the block of one Embodiment. It is an expanded view of the block of one Embodiment. (A), (b) is a top view of the sipe of other embodiment. (A), (b) is a top view of the sipe of other embodiment. It is an expanded view of the tread part which shows a comparative example.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a development view of a tread portion 2 of a tire 1 showing an embodiment of the present invention. In this embodiment, a pneumatic tire for a passenger car is shown as a preferable aspect. However, it goes without saying that the present invention can also be applied to other categories of tires 1 such as for heavy loads.

  As shown in FIG. 1, the tread portion 2 of the present embodiment is provided with a plurality of blocks 4.

  In the present embodiment, the block 4 is sandwiched between the shoulder block 4A disposed closest to the tread end Te, the crown block 4B disposed closest to the tire equator C, and the shoulder block 4A and the crown block 4B. The middle block 4C is included. In the present embodiment, the blocks 4A to 4C are spaced apart in the tire circumferential direction.

  The “tread end” Te is a normal load obtained by applying a normal load to a flat tire with a camber angle of 0 degrees on a normal tire 1 in a normal state in which a normal rim is assembled and filled with a normal internal pressure. It is determined as the ground contact position on the outermost side in the tire axial direction in the loaded state. In the normal state, the distance in the tire axial direction between the tread ends Te and Te is determined as the tread width TW. When there is no notice in particular, the dimension of each part of the tire 1 is a value measured in a normal state.

  The “regular rim” is a rim determined for each tire in the standard system including the standard on which the tire is based. For example, “standard rim” for JATMA, “Design Rim” for TRA, “ETRTO” Then "Measuring Rim".

  “Normal internal pressure” is the air pressure that each standard defines for each tire in the standard system including the standard on which the tire is based. “JATIMA” is the “maximum air pressure”, TRA is the table “TIRE LOAD LIMITS” The maximum value described in “AT VARIOUS COLD INFLATION PRESSURES”, “INFLATION PRESSURE” in the case of ETRTO.

  “Regular load” is the load that each standard defines for each tire in the standard system including the standard on which the tire is based. It is “Maximum load capacity” for JATMA and “TIRE LOAD” for TRA. The maximum value described in “LIMITS AT VARIOUS COLD INFLATION PRESSURES”, or “LOAD CAPACITY” in ETRTO.

  FIG. 2 is a plan view showing an example of the block 4 of the present embodiment. As shown in FIG. 2, the tread surface 4 a of the block 4 is sandwiched between a first edge 5 and a second edge 6 extending in the tire circumferential direction. The tread 4a of the present embodiment further includes a third edge 7 extending in the tire tire axial direction at one end of the first edge 5 and the second edge 6 in the tire circumferential direction, and a first edge 5 and a second edge 6. The other end in the tire circumferential direction is sandwiched between the fourth edges 8 extending in the joint tire axial direction.

  A full open sipe 10, a first semi-open sipe 11, and a second semi-open sipe 12 are provided on the tread surface 4 a of the block 4. The full open sipe 10 extends from the first edge 5 to the second edge 6. The first semi-open sipe 11 is disposed adjacent to one side (upper side in the drawing) of the full-open sipe 10 and extends from the first edge 5 to reach both the full-open sipe 10 and the second edge 6. It has a discontinuous end 11e that terminates without termination. The second semi-open sipe 12 is disposed adjacent to the other side (lower side in the drawing) of the full-open sipe 10 in the tire circumferential direction and extends from the second edge 6 to reach the full-open sipe 10 and the first edge 5. It has a discontinuous end 12e that terminates without. Since the full open sipe 10, the first semi-open sipe 11, and the second semi-open sipe 12 exhibit a large frictional force, snow and ice road performance is improved. Moreover, since the 1st semi open sipe 11 and the 2nd semi open sipe 12 can suppress the rigidity fall of a block, exhibiting the said effect | action, the reduction of steering stability performance is suppressed.

  In the present specification, each “sipe” is defined as a cut having a width of less than 2 mm.

  Each of the first semi-open sipe 11 and the second semi-open sipe 12 extends in a direction approaching a virtual straight line 10c that connects both ends 10a and 10b of the full-open sipe 10 toward the cut ends 11e and 12e. Thereby, since the rigidity of a block is equalized, the crack which started from each sipe 10 thru | or 12 is suppressed. For this reason, since the rigidity reduction of a block is suppressed small, steering stability performance is further maintained. Therefore, the tire 1 of the present invention improves snow and ice road performance while maintaining steering stability performance.

  In the present invention, as long as at least one block 4 is provided with a full open sipe 10, a first semi-open sipe 11, and a second semi-open sipe 12, the above-described configuration is used regardless of the shape of the tread 4a of the block 4. The effect is demonstrated.

  In this embodiment, the full open sipe 10 is formed in a zigzag shape having a first apex portion 15 and a second apex portion 16 projecting toward the one side and the other side in the tire circumferential direction with respect to the virtual straight line 10c. Since such a full open sipe 10 has multidirectional edge components, the snow and ice road performance is maintained high.

  In the present embodiment, the first top portion 15 and the second top portion 16 are vertices that are farthest away from the virtual straight line 10c toward the one side and the other side in the tire circumferential direction. Thereby, a large edge component is obtained.

  The full open sipe 10 includes a tilt element 17, a first edge side tilt element 18, and a second edge side tilt element 19. The tilting element 17 connects between the first top 15 and the second top 16. The first edge-side inclined element 18 extends from the second top 16 to the first edge 5 with an inclination opposite to the inclined element 17. The second edge side inclined element 19 extends from the first top 15 to the second edge 6 with an inclination opposite to the inclined element 17. In such a full open sipe 10, the opening and closing of the sipe is restricted, so that cracks in the block 4 are suppressed.

  In the present embodiment, the inclination element 17 is inclined to one side in the tire axial direction (upward to the left in the drawing) and linearly extends. In the present specification, the “straight shape” includes a mode in which both ends are joined in a straight line, and a mode in which the ends are joined in a smooth arc shape without having a bent portion. The inclination element 17 is not limited to such a linearly extending aspect, and may be, for example, an aspect having a bent portion and extending to one side in the tire axial direction at different inclination angles.

  In the present embodiment, the first edge-side inclined element 18 joins the main portion 18a inclined from the second top portion 16 in the opposite direction to the inclined element 17, and the main portion 18a and one end 10a and extends along the tire axial direction. The axial direction part 18b is included. Such a first edge-side tilting element 18 causes the axial direction portion 18b to exert a large frictional force with respect to straight traveling, and the main portion 18a has a tire circumferential direction component. Make it work. In the present specification, the “axial portion extending along the tire axial direction” includes not only an aspect extending parallel to the tire axial direction, but also other inclined elements having continuous axial portions (mainly in this embodiment). Part) extending at a smaller angle than the tire axial direction. For example, it is desirable that the axial portion extends at an angle α of 5 degrees or less with respect to the tire axial direction.

  The 1st edge side inclination element 18 is not limited to such an aspect, For example, the aspect extended linearly between the 2nd top part 16 and the one end 10a may be sufficient (illustration omitted).

  In the present embodiment, the second edge-side inclined element 19 extends linearly between the first top portion 15 and the other end 10b. Note that the second edge-side inclined element 19 is not limited to such an aspect, and includes, for example, a main portion 19a and an axial direction portion 19b, similarly to the first edge-side inclined element 18. (It is shown in FIG. 4).

  The angle θ1 between the inclined element 17 and the first edge-side inclined element 18 is preferably 110 to 130 degrees. In addition, it is desirable that the angle θ2 between the tilt element 17 and the second edge side tilt element 19 is 110 to 130 degrees. When the angles θ1 and θ2 are less than 110 degrees, the rigidity is reduced between the inclined element 17 and the first edge-side inclined element 18, or between the inclined element 17 and the second edge-side inclined element 19, There is a risk that steering stability will deteriorate. When the angles θ1 and θ2 exceed 130 degrees, the inclination element 17 and the first edge side inclination element 18 or the inclination element 17 and the second edge side inclination element 19 approach one straight line. There is a possibility that the opening and closing of can not be suppressed. In this specification, when each edge side inclination element 18 and 19 includes an axial part, the said angles (theta) 1 and (theta) 2 are measured by the angle between each main part 18a, 19a and the inclination element 17. FIG.

  FIG. 3 is a plan view showing an example of the block 4 of the present embodiment. As shown in FIG. 3, the first semi-open sipe 11 is inclined in the same direction as the second edge-side inclined element 19 in the present embodiment. Thereby, since the big frictional force of the same direction is exhibited by the 2nd edge side inclination element 19 and the 1st semi-open sipe 11, snow and ice road performance is improved.

  In the present embodiment, the first semi-open sipe 11 joins the main portion 11a extending from the discontinuous end 11e toward the first edge 5 side, and the main portion 11a and one end 11i on the first edge 5 side, and in the tire axial direction. The axial direction part 11b extended along. The first semi-open sipe 11 is not limited to such a mode, and may be a mode in which the discontinuous end 11e and the one end 11i are joined in a straight line (not shown).

  In the present embodiment, the discontinuous end 11e of the first semi-open sipe 11 is located in an in-projection region 17A obtained by projecting the inclined element 17 in the tire circumferential direction. Since the first semi-open sipe 11 has a large edge component, it exhibits excellent snow and ice road performance. In FIG. 3, the in-projection area 17A of the first semi-open sipe 11 is indicated by hatching.

  In order to effectively exhibit the above-described action, it is desirable that the discontinuous end 11e of the first semi-open sipe 11 is located at a distance La of 5 mm or less from the first top portion 15. In addition, when the distance La between the discontinuous end 11e of the first semi-open sipe 11 and the first top portion 15 is less than 2 mm, the rigidity of the block 4 becomes excessively small, and the discontinuous end 11e and the first top portion 15 are the starting points. There is a risk that cracks are likely to occur. For this reason, the distance La is desirably 2 mm or more.

  The first semi-open sipe 11 is inclined in the same direction as the third edge 7. Thereby, the rigidity step in the tire circumferential direction of the block 4 between the first semi-open sipe 11 and the second edge-side inclined element 19 and the third edge 7 is kept small.

  In the present embodiment, the second semi-open sipe 12 is inclined in the same direction as the first edge-side inclined element 18. Thereby, since a big frictional force is exhibited by the 1st edge side inclination element 18 and the 2nd semi-open sipe 12, snow and ice road performance is improved.

  In the present embodiment, the second semi-open sipe 12 extends linearly between the interrupted end 12e and the other end 12i on the second edge 6 side. The second semi-open sipe 12 is not limited to such an aspect. The second semi-open sipe 12 includes, for example, a main portion 12a extending from the discontinuous end 12e toward the second edge 6, and an axial portion 12b extending from the main portion 12a and the other end 12i along the tire axial direction. May be included (shown in FIG. 4).

  In the present embodiment, the discontinuous end 12e of the second semi-open sipe 12 is located in the in-projection region 17A. Since the second semi-open sipe 12 has a large edge component, the snow and ice road performance is improved.

  The discontinuous end 12e of the second semi-open sipe 12 is located at a distance La of 2 to 5 mm from the second top portion 16 for the same reason as the disposition position of the discontinuous end 11e of the first semi-open sipe 11. desirable.

  The second semi-open sipe 12 is inclined in the same direction as the fourth edge 8. Thereby, the rigidity step in the tire circumferential direction of the block 4 between the second semi-open sipe 12 and the first edge-side inclined element 18 and the fourth edge 8 is kept small.

  In the present embodiment, the first edge 5 is provided on the outer side in the tire axial direction than the second edge 6. And the 1st edge side inclination element 18 and the 1st semi-open sipe 11 have the axial direction parts 18b and 11b, respectively. Thereby, since the tire axial direction rigidity of the block 4 on the first edge 5 side on which a large lateral force acts is maintained largely, cracking of the block is suppressed.

  It is desirable that two or more of the first semi-open sipe 11, the second semi-open sipe 12, the first edge-side inclined element 18, and the second edge-side inclined element 19 have an axial portion. Thereby, the stability at the time of straight running on a snowy and ice road is highly improved.

  In order to effectively exhibit the above-described action, the depth of each sipe 10 to 12 is desirably 70% to 90% of the block height of the block 4.

  FIG. 4 is a development view showing an embodiment of the block 4. As shown in FIG. 4, the block 4 includes a first block 20 and a second block 21 in the present embodiment. In the present embodiment, the first block 20 and the second block 21 are alternately arranged in the tire circumferential direction. In the first block 20, the second edge 6 extends in a zigzag shape having a bent portion 22 at the central portion 6a in the tire circumferential direction. In the present embodiment, the second edge 6 of the first block 20 is provided with one bent portion 22a that protrudes outward in the tire axial direction and one bent portion 22b that protrudes inward in the tire axial direction. It has been. In the second block 21, the second edge 6 is inclined smoothly and continuously on one side in the tire axial direction at the central portion 6 a in the tire circumferential direction. In the present specification, the “center portion in the tire circumferential direction” means a tire circumference that is 30% to 70% of the tire circumferential direction length Lb of the second edge 6 from one end to the other end of the second edge 6. This refers to the direction area.

  Although not particularly limited, in the present embodiment, the first edge 20 of the first block 20 and the second block 21 includes a bent portion 22a that protrudes inward in the tire axial direction at the central portion 5a and an outer side in the tire axial direction. One bent portion 22b is provided.

  Thus, the shape of the second edge 6 is different between the first block 20 and the second block 21, and the rigidity of the first block 20 on the second edge 6 side is the second edge 6 of the second block 21. Each block 20, while increasing the frictional force on ice, by defining the sipe angle, the sipe length ratio, and the ratio of the width of the block in the tire axial direction as follows: The rigidity of 21 can be made uniform.

  In the first block 20 of the present embodiment, the second semi-open sipe 12 and the second edge side inclined element 19 extend linearly. In the second block 21 of the present embodiment, the second semi-open sipe 12 and the second edge-side inclined element 19 have main portions 12a and 19a and axial portions 12b and 19b, respectively.

  In the first block 20, the angle θ3 of the first semi-open sipe 11 with respect to the tire axial direction is preferably 10 to 30 degrees. In the first block 20, the angle θ4 of the second semi-open sipe 12 with respect to the tire axial direction is preferably 20 to 40 degrees. Thereby, snow and ice road performance is exhibited effectively.

  In the first block 20, the ratio (L2 / L1) of the length L1 of the main part 11a of the first semi-open sipe 11 to the length L2 of the second semi-open sipe 12 is, for example, 1.1 to 1.2. It is desirable.

  In the second block 21, the angle θ5 of the first semi-open sipe 11 with respect to the tire axial direction is preferably 15 to 35 degrees. In the second block 21, the angle θ6 of the second semi-open sipe 12 with respect to the tire axial direction is preferably 15 to 35 degrees.

  In the second block 21, the ratio (L4 / L3) of the length L3 of the main portion 11a of the first semi-open sipe 11 to the length L4 of the main portion 12a of the second semi-open sipe 12 is, for example, 0.75 It is desirable that it be 0.85.

  In order to improve snow and ice road performance while suppressing reduction in steering stability performance, the tire axial width Wb of the second block 21 is preferably larger than the tire axial width Wa of the first block 20. More specifically, the tire axial direction width Wb of the second block 21 is more preferably more than 1.0 times and not more than 1.1 times the tire axial direction width Wa of the first block 20.

  As shown in FIG. 1, in this embodiment, such a full open sipe 10, a first semi-open sipe 11, and a second semi-open sipe 12 are formed in all the middle blocks 4C arranged in the tire circumferential direction. Has been. The middle block 4 </ b> C is a block 4 on which the ground pressure due to straight traveling and the lateral force due to turning travel greatly act. For this reason, by providing the sipes 10 to 12 in the middle block 4C, the traveling performance on the snow and ice road surface is improved in both the turning traveling and the straight traveling.

  It should be noted that the sipes 10 to 12 of the present invention are not limited to those arranged in the middle block 4C, but may be provided in the crown block 4B or the shoulder block 4A.

  A lateral groove 30 is formed between the first block 20 and the second block 21. The horizontal groove 30 of the present embodiment is provided with a tie bar 31 having a groove bottom 30s raised. Thereby, since the deformation | transformation of the block 4 at the time of driving | running | working is restrict | limited, the crack of a block is suppressed. The tie bar 31 of the present embodiment extends from the inner end of the block 4 in the tire axial direction to the outer side in the tire axial direction.

  In the present embodiment, the tie bar 31 is provided with a sipe 32 on the outer surface 31a in the tire radial direction. The sipe 32 extends linearly along the groove center line 30 c of the lateral groove 30. In this embodiment, both ends of the sipe 32 are terminated in the outer surface 31a. Such a sipe 32 effectively reduces the rigidity of the tie bar 31 and smoothly discharges snow in the lateral groove 30 to improve snow and ice road performance.

  FIG. 5A shows a sipe according to another embodiment that exhibits the same effect as the present invention. About the same structure as the sipe of this embodiment, the same code | symbol is attached | subjected and the description is abbreviate | omitted. In this embodiment, the first semi-open sipe 11A and the second semi-open sipe 12A are arranged facing each other with the inclined element 17 interposed therebetween so as to form one smooth virtual sipe.

  FIG. 5 (b) shows a sipe of still another embodiment that exhibits the same effect as the present invention. About the same structure as the sipe of this embodiment, the same code | symbol is attached | subjected and the description is abbreviate | omitted. In this embodiment, the full open sipe 10B includes an inclined element 17B extending along the tire circumferential direction, a first edge-side inclined element 18B extending along the tire axial direction, and a second edge side extending along the tire axial direction. And an inclined element 19B. The first semi-open sipe 11B extends along the tire axial direction so as to form one smooth sipe with the second edge-side inclined element 19B. The second semi-open sipe 12B extends along the tire axial direction so as to form one smooth virtual sipe with the first edge-side inclined element 18B.

  FIG. 6A shows a sipe according to still another embodiment that exhibits the same effect as the present invention. About the same structure as the sipe of this embodiment, the same code | symbol is attached | subjected and the description is abbreviate | omitted. In this embodiment, the full open sipe 10C is inclined from the first edge 5 to the second edge 6 on one side (downward in the drawing) with respect to the tire axial direction. The first edge side inclination element 18C and the second edge side inclination element 19C are inclined at a smaller angle than the inclination element 17C with respect to the tire axial direction. The first semi-open sipe 11 </ b> C has an inclination opposite to that of the full-open sipe 10, and ends with a distance La of 2 to 5 mm from the first top portion 15. The second semi-open sipe 12C has an inclination opposite to that of the full-open sipe 10 and terminates with a distance La of 2 to 5 mm from the second top portion 16.

  FIG. 6 (b) shows a sipe of still another embodiment that exhibits the same effect as the present invention. About the same structure as the sipe of this embodiment, the same code | symbol is attached | subjected and the description is abbreviate | omitted. In this embodiment, the full open sipe 10 </ b> D extends linearly from the first edge 5 to the second edge 6. The first semi-open sipe 11D and the second semi-open sipe 12D are arranged so as to form one smooth virtual sipe with the full-open sipe 10D interposed therebetween.

  As mentioned above, although embodiment of this invention was explained in full detail, it cannot be overemphasized that this invention is not limited to exemplary embodiment, and can be deform | transformed and implemented in a various aspect.

Tires of size 265 / 60R18 having the basic pattern of FIG. 1 were prototyped based on the specifications in Table 1, and the snow / ice road performance and steering stability performance of each sample tire were tested. The main common specifications and test methods for each sample tire are as follows.
Middle block height: 10.5mm

<Snow and ice road performance / steering stability performance>
Each sample tire was mounted on all wheels of a 3600cc four-wheel drive vehicle under the following conditions. Then, the test driver drove the test course on the snow and ice road surface and the dry asphalt road surface, and the driving characteristics regarding the traction, the driving stability, and the steering performance at this time were evaluated based on the sensuality of the test driver. The results are displayed with a score of Comparative Example 1 being 100. The larger the value, the better.
Rims: 18x7.5J
Internal pressure: 240 kPa (all wheels)
Table 1 shows the test results.

  As a result of the test, it was confirmed that the snow of the example was improved in the tire of the example while suppressing a great reduction in the steering stability performance as compared with the tire of the comparative example.

DESCRIPTION OF SYMBOLS 1 Tire 4a Tread 5 First edge 6 Second edge 10 Full open sipe 11 First semi-open sipe 11e First semi-open sipe break 12 Second semi-open sipe 12e Second semi-open sipe break 10c Virtual straight line

Claims (11)

A tire provided with a plurality of blocks in the tread portion,
At least one of the blocks has a tread sandwiched between a first edge and a second edge extending in the tire circumferential direction,
The tread has a full open sipe extending from the first edge to the second edge;
A first semi-open sipe having a discontinuous end disposed adjacent to one side in the tire circumferential direction of the full-open sipe and extending from the first edge and terminating without reaching both the full-open sipe and the second edge When,
A second semi-open sipe that is disposed adjacent to the other side of the tire in the circumferential direction of the full-open sipe and has a discontinuous end that extends from the second edge and terminates without reaching the full-open sipe and the first edge; Is provided,
Each of the first semi-open sipe and the second semi-open sipe extends in a direction approaching an imaginary straight line connecting both ends of the full-open sipe toward the respective discontinuous ends.   2. The tire according to claim 1, wherein the full open sipe has a zigzag shape having a first apex portion and a second apex portion that protrude toward the one side and the other side in the tire circumferential direction with respect to the virtual straight line. The full open sipe includes an inclined element that is inclined with respect to the virtual straight line and connects between the first top and the second top.
3. The tire according to claim 2, wherein the discontinuous end of the first semi-open sipe is located in a projection region in which the inclined element is projected in the tire circumferential direction.   The tire according to claim 3, wherein the discontinuous end of the first semi-open sipe is located 2 to 5 mm apart from the first top portion. The full open sipe includes an inclined element that is inclined with respect to the virtual straight line and connects between the first top and the second top.
The tire according to any one of claims 2 to 4, wherein the discontinuous end of the second semi-open sipe is located in a projection region obtained by projecting the inclined element in the tire circumferential direction.   The tire according to claim 5, wherein the discontinuous end of the second semi-open sipe is located 2 to 5 mm apart from the second top portion. The full-open sipe includes a second edge-side inclined element extending from the first top to the second edge with an inclination opposite to the inclined element;
The tire according to any one of claims 3 to 6, wherein the first semi-open sipe is inclined in the same direction as the second edge-side inclined element. The full open sipe includes a first edge-side inclined element that extends from the second top to the first edge with an inclination opposite to the inclined element;
The tire according to any one of claims 3 to 7, wherein the second semi-open sipe is inclined in the same direction as the first edge-side inclined element. The full-open sipe includes a second edge-side inclined element extending from the first top to the second edge with an inclination opposite to the inclined element;
The angle between the inclined element and the first edge-side inclined element is 110 to 130 degrees,
The tire according to claim 8, wherein an angle between the inclined element and the second edge-side inclined element is 110 to 130 degrees. The first edge is arranged on the outer side in the tire axial direction than the second edge,
The tire according to claim 9, wherein the first edge-side inclined element has an axial direction portion extending along a tire axial direction at an end portion on the first edge side. The block includes a first block in which the second edge extends zigzag, and a second block in which the second edge extends smoothly,
The first block has an angle with respect to the tire axial direction of the first semi-open sipe of 10 to 30 degrees, and an angle with respect to the tire axial direction of the second semi-open sipe is 20 to 40 degrees,
11. The second block has an angle with respect to a tire axial direction of the first semi-open sipe of 15 to 35 degrees, and an angle with respect to a tire axial direction of the second semi-open sipe is 15 to 35 degrees. The tire according to any one of the above.

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