JP6481289B2 - Pneumatic tire - Google Patents

Description

  The present invention relates to a pneumatic tire.

  As disclosed in Patent Document 1, the pneumatic tire includes a block defined by a groove provided in a tread portion. The block has an edge that defines the contour of the ground plane.

Special table 2013-516346 gazette

  A studless tire is known as one of pneumatic tires. The studless tire has a plurality of subdivided blocks. A high edge effect can be obtained by subdividing the blocks. Due to the high edge effect, the performance on ice (ice running performance) of the pneumatic tire can be improved. The pneumatic tire drives, brakes, and turns. In each of these driving, braking, and turning, an improvement in performance on ice of a pneumatic tire is desired.

  An object of an aspect of the present invention is to provide a pneumatic tire capable of improving the performance on ice in each of driving, braking, and turning.

  An aspect of the present invention is defined by a block having an edge defined by a narrow groove provided in a tread portion, a grounding surface disposed inside the edge, and a plurality of the blocks adjacent to each other through the narrow groove. And an edge of the block is provided between the first line, the second line, one end of the first line and one end of the second line, and protrudes outward. A first corner, a third line, a fourth line, a second corner that is provided between one end of the third line and one end of the fourth line and is recessed inward, and the first line A fifth line connecting the other end of the third line and the other end of the third line, a sixth line connecting the other end of the second line and the other end of the fourth line, and the third line. And a third corner provided between the first line and the fifth line A fourth corner provided between the fourth line and the sixth line, and the plurality of blocks of the block group are each around a virtual point set inside the narrow groove, respectively. The first corner of the first block group is disposed so as to face the virtual point, and the block group includes a first block group and a second block group adjacent to the first block group, and the first block group And the second block group is a pneumatic tire arranged such that the third corner of the block of the first block group and the fourth corner of the block of the second block group are opposed to each other. provide.

  According to the aspect of the present invention, the edge (outer shape) of the block that defines the outer shape of the ground plane by the first corner protruding outward and the second corner recessed inward has anisotropy. Accordingly, the pneumatic tire can obtain a high edge effect in each of driving, braking, and turning.

  Moreover, according to the aspect of the present invention, a block group is defined by a plurality of blocks adjacent via the narrow groove. The block group is defined by a plurality of blocks arranged around an imaginary point set inside the narrow groove. These blocks are arranged such that the first corner faces the virtual point. In other words, the plurality of blocks in the block group are arranged so as to face each other with their first corners close to each other. Thus, the edges of the blocks having anisotropy are arranged in various directions. Therefore, even if forces in various directions act on the tread portion, the pneumatic tire can obtain a high edge effect. Accordingly, the pneumatic tire can improve the performance on ice in each of driving, braking, and turning.

  Further, the blocks in the block group are adjacent to each other through a narrow groove. Therefore, even if a force acts on a certain block among the plurality of blocks and the block is about to fall down, it is supported by the adjacent block. Thereby, the fall of a block is suppressed. By suppressing the collapse of the block, the on-ice performance of the pneumatic tire can be improved in each of driving, braking, and turning.

  In the tread portion, the block group includes a first block group and a second block group adjacent to the first block group. That is, a plurality of adjacent block groups are provided in the tread portion. The third corners of the blocks of the first block group are arranged so as to face the fourth corners of the blocks of the adjacent second block group. That is, the first block group and the second block group are arranged so that the third corner of the first block group and the fourth corner of the second block group are close to each other and face each other. Thereby, a plurality of block groups are arranged so as to be dense, and a plurality of blocks are arranged so as to be dense. As a result, a higher edge effect is obtained and the collapse of the block is sufficiently suppressed. Therefore, the performance on ice of the pneumatic tire can be greatly improved in each of driving, braking, and turning.

  In the aspect of the present invention, the edge of the block includes a fifth corner provided between the other end of the first line and the fifth line, the other end of the second line, and the sixth line. And a sixth corner provided between the first and second corners.

  Thereby, even if forces in various directions act on the tread portion by the six lines and the six corners, the pneumatic tire can obtain a high edge effect. Accordingly, the pneumatic tire can improve the performance on ice in each of driving, braking, and turning.

  In the aspect of the present invention, the first line and the third line may be parallel, and the second line and the fourth line may be parallel.

  Thereby, a high edge effect is obtained and the performance on ice is improved.

  In the aspect of the present invention, the fifth line and the sixth line may be parallel.

  Thereby, a high edge effect is obtained and the performance on ice is improved.

  In the aspect of the present invention, the block group includes three blocks arranged around the virtual point, and a plurality of the second block groups are arranged around the first block group. All of the three third corners of the group are opposed to the fourth corner of the second block group, and all of the three fourth corners of the first block group are of the second block group. You may oppose the said 3rd corner.

  Thereby, it arrange | positions so that a some block group may be crowded, and while being able to obtain a high edge effect, the fall of a block is suppressed.

  In the aspect of the present invention, the block group includes four blocks arranged around the virtual point, and a plurality of the second block groups are arranged around the first block group. All of the four third corners of the group are opposed to the fourth corner of the second block group, and all of the four fourth corners of the first block group are of the second block group. You may oppose the said 3rd corner.

  Thereby, it arrange | positions so that a some block group may be crowded, and while being able to obtain a high edge effect, the fall of a block is suppressed.

  In the aspect of the present invention, among the four blocks arranged around the virtual point, the first corner of the first block, the second corner of the first block, and the first corner of the third block And the second corner of the third block are arranged on a first straight line, and among the four blocks arranged around the virtual point, the first corner of the second block and the second block The second corner of the fourth block, the first corner of the fourth block, and the second corner of the fourth block are arranged on a second straight line, and the first straight line and the second straight line are orthogonal to each other. Also good.

  Thereby, high on-ice performance is obtained.

  In the aspect of the present invention, the block group includes six blocks arranged around the virtual point, and a plurality of the second block groups are arranged around the first block group, and the first block Four of the six third corners of the group are opposed to the fourth corner of the second block group, and four of the six fourth corners of the first block group are four. The fourth corner may face the third corner of the second block group.

  Thereby, it arrange | positions so that a some block group may be crowded, and while being able to obtain a high edge effect, the fall of a block is suppressed.

  In the aspect of the present invention, among the six blocks arranged around the virtual point, the first corner of the first block, the second corner of the first block, and the first corner of the fourth block And the second corner of the fourth block are arranged on a first straight line, and the first straight line of the first block group and the first straight line of the second block group are arranged on the same straight line. May be.

  Thereby, high on-ice performance is obtained.

  In the aspect of the present invention, the block group includes six blocks arranged around the virtual point, and a plurality of the second block groups are arranged around the first block group, and the first block All of the six third corners of the group are opposed to the fourth corner of the second block group, and all of the six fourth corners of the first block group are of the second block group. You may oppose the said 3rd corner.

  Thereby, it arrange | positions so that a some block group may be crowded, and while being able to obtain a high edge effect, the fall of a block is suppressed.

  In an aspect of the present invention, among the six blocks arranged around the virtual point, the narrow groove that separates the first block and the second block, and the narrow groove that separates the fourth block and the fifth block; May be arranged on a first straight line, and the first straight line of the first block group and the first straight line of the second block group may be arranged on the same straight line.

  Thereby, high on-ice performance is obtained.

  In the aspect of the present invention, among the six blocks arranged around the virtual point, the first corner of the first block, the second corner of the first block, and the first corner of the fourth block And the second corner of the fourth block are arranged on a first straight line, and the first straight line of the first block group and the first straight line of the second block group are arranged on the same straight line. May be.

  Thereby, high on-ice performance is obtained.

  In the aspect of the present invention, each dimension of the first line, the second line, the third line, the fourth line, the fifth line, and the sixth line may be 5 mm or more and 25 mm or less.

  Thereby, the fall of block rigidity and the fall of an edge effect are suppressed. If the dimension is smaller than 5 mm, the block rigidity is lowered, and as a result, the performance on ice may be lowered. When the dimension is larger than 25 mm, a sufficient edge effect cannot be obtained, and as a result, the performance on ice is lowered.

  In the aspect of the present invention, an angle formed by the first line and the second line is 40 degrees or more and 160 degrees or less, and an angle formed by the third line and the fourth line is 200 degrees or more and 320 degrees. It may be the following.

  Thereby, the fall of a block and the fall of an edge effect are suppressed. If the angle formed by the first line and the second line is smaller than 40 degrees, the block rigidity is locally reduced, and as a result, the possibility that the block collapses increases. If the angle formed by the first line and the second line is larger than 160 degrees, the edge effect of the block may be reduced. When the angle formed by the third line and the fourth line is larger than 320 degrees, the block rigidity is locally reduced, and as a result, the possibility that the block collapses increases. If the angle formed by the third line and the fourth line is smaller than 200 degrees, the edge effect of the block may be lowered.

  In the aspect of the present invention, the first line and the fifth line may be arranged on the same straight line, and the second line and the sixth line may be arranged on the same straight line.

  Thereby, high on-ice performance can be obtained by the block having four sides.

  In the aspect of the present invention, the dimension of the first line and the dimension of the second line may be substantially equal, and the dimension of the third line and the dimension of the fourth line may be substantially equal.

  Thereby, high on-ice performance can be obtained by a block having a line-symmetric outer shape. In addition, the blocks can be made dense.

  In the aspect of the present invention, the width of the narrow groove may be 1 mm or more and 4 mm or less.

  Thereby, falling of a block can be suppressed, maintaining the water removal effect of a tread part. When the width of the narrow groove is smaller than 1 mm, the water removal effect is lowered. When the width of the narrow groove is larger than 4 mm, when a certain block falls, it becomes difficult for the adjacent block to support, and as a result, the block falls.

  In the aspect of the present invention, a sipe provided in the block may be provided.

  As a result, the performance on ice can be further improved. In addition, a sipe is a groove | channel whose width is 0.4 mm or more and less than 1.0 mm, and is thinner than the above-mentioned fine groove.

  According to the aspect of the present invention, a pneumatic tire capable of improving the performance on ice in each of driving, braking, and turning is provided.

FIG. 1 is a cross-sectional view showing a part of the pneumatic tire according to the first embodiment. FIG. 2 is a plan view illustrating an example of a tread portion of the pneumatic tire according to the first embodiment. FIG. 3 is a plan view showing an example of a block according to the first embodiment. FIG. 4 is an enlarged plan view of a part of the tread portion according to the first embodiment. FIG. 5 is an enlarged plan view of a part of the tread portion according to the first embodiment. FIG. 6 is an enlarged plan view of a part of the tread portion according to the first embodiment. FIG. 7 is a diagram in which three block groups are extracted from a plurality of block groups according to the first embodiment. FIG. 8 is a plan view showing an example of a block according to the second embodiment. FIG. 9 is an enlarged plan view of a part of the tread portion according to the second embodiment. FIG. 10 is an enlarged plan view of a part of the tread portion according to the second embodiment. FIG. 11 is a diagram in which five block groups are extracted from a plurality of block groups according to the second embodiment. FIG. 12 is a plan view illustrating an example of a block according to the third embodiment. FIG. 13 is an enlarged plan view of a part of the tread portion according to the third embodiment. FIG. 14 is an enlarged plan view of a part of the tread portion according to the third embodiment. FIG. 15 is an enlarged plan view of a part of the tread portion according to the fourth embodiment. FIG. 16 is an enlarged plan view of a part of the tread portion according to the fourth embodiment. FIG. 17 is a plan view showing an example of a block according to the fifth embodiment. FIG. 18 is a plan view showing an example of a block according to the fifth embodiment. FIG. 19 is a plan view showing an example of a block according to the fifth embodiment. FIG. 20 is a plan view showing an example of a block according to the fifth embodiment. FIG. 21 is a plan view showing an example of a block according to the fifth embodiment. FIG. 22 is a plan view showing an example of a block according to the sixth embodiment. FIG. 23 is a plan view showing an example of a block according to the sixth embodiment. FIG. 24 is a diagram showing the results of a performance test of the pneumatic tire according to the present embodiment. FIG. 25 is a view showing a pneumatic tire according to a conventional example. FIG. 26 is a view showing a pneumatic tire according to a conventional example.

  Hereinafter, embodiments according to the present invention will be described with reference to the drawings, but the present invention is not limited thereto. The components of the embodiments described below can be combined as appropriate. Some components may not be used.

<First Embodiment>
A first embodiment will be described. FIG. 1 is a cross-sectional view showing a part of a pneumatic tire 1 according to this embodiment. FIG. 1 shows a meridional section passing through the rotation axis AX of the pneumatic tire 1. FIG. 2 is a plan view illustrating an example of the tread portion 3 of the pneumatic tire 1 according to the present embodiment.

  The pneumatic tire 1 rotates around the rotation axis AX. In the following description, a rotation direction around the rotation axis AX is appropriately referred to as a circumferential direction, a direction parallel to the rotation axis AX is appropriately referred to as a width direction, and a radial direction with respect to the rotation axis AX is appropriately determined as a radial direction. . A center line (equatorial line) CL of the pneumatic tire 1 passes through the center of the pneumatic tire 1 in the width direction.

  In the present embodiment, the pneumatic tire 1 is a studless tire having a plurality of subdivided blocks 30. In the following description, the pneumatic tire 1 is appropriately referred to as a tire 1.

  As shown in FIG. 1, the tire 1 includes a tread portion 3 having a ground contact surface 2, a bead portion 4 connected to a rim, and a sidewall portion 5 that connects the tread portion 3 and the bead portion 4. . The ground contact surface 2 is in contact with the road surface (ground) when the tire 1 is traveling.

  The tire 1 has a carcass 6 and an inner liner 7. The carcass 6 is a skeleton of the tire 1 and maintains the shape of the tire 1. The inner liner 7 is disposed so as to face the internal space of the tire 1. The carcass 6 and the inner liner 7 are disposed in the tread portion 3, the bead portion 4, and the sidewall portion 5.

  The bead portion 4 includes a bead core 11 and a bead filler 12. The bead core 11 fixes the tire 1 to the rim. The bead cores 11 are disposed on both sides of the center line CL of the tire 1 in the width direction. The bead core 11 includes a plurality of bundled high carbon steel annular members. The bead core 11 is disposed so as to surround the rotation axis AX. The bead filler 12 increases the rigidity of the bead portion 4.

  The tread portion 3 includes a belt 14 and a tread rubber 15. The belt 14 includes a plurality of stacked belt materials. The belt 14 is disposed outside the carcass 6 with respect to the radial direction. The belt 14 tightens the carcass 6 to increase the rigidity of the tread portion 3. A tread pattern is formed on the tread rubber 15. The tread rubber 15 is disposed outside the carcass 6 and the belt 14 in the radial direction. The ground contact surface 2 is disposed on the tread rubber 15.

  The sidewall portion 5 includes a sidewall rubber 16. The sidewall portions 5 are disposed on both sides of the center line CL in the width direction.

  The carcass 6 is disposed in a toroidal shape between the bead core 11 on one side and the bead core 11 on the other side of the center line CL in the width direction. Both ends of the carcass 6 are folded back so as to surround the bead filler 12.

  Grooves 8 are formed in the tread rubber 15. The tread pattern is formed by the grooves 8. The groove 8 includes a main groove 9 formed in the circumferential direction of the tire 1, a lug groove formed in the width direction of the tire 1, and a narrow groove 20. The block 30 is formed by the tread rubber 15 being partitioned by the narrow groove 20. The ground plane 2 includes the surface of the block 30.

  The main groove 9 is formed in the circumferential direction of the tire 1. At least a part of the main groove 9 is provided in the center portion of the tread portion 3 of the tire 1. The main groove 9 has a tread wear indicator inside. The treadwear indicator indicates the end of wear. The main groove 9 has a width of 4.0 mm or more and may have a depth of 5.0 mm or more.

  At least a part of the lug groove is formed in the width direction of the tire 1. The lug groove has a width of 1.5 mm or more. The lug groove may have a depth of 4.0 mm or more, and may partially have a depth of less than 4.0 mm.

  The narrow groove 20 is formed in each of the circumferential direction, the width direction, the direction inclined with respect to the circumferential direction, and the direction inclined with respect to the width direction of the tire 1. The narrow groove 20 is provided in each of the center portion and the shoulder portion of the tread portion 3 of the tire 1. The narrow groove 20 has a width of 1 mm or more and 4 mm or less.

  A plurality of blocks 30 are formed in the tread portion 3 by the narrow grooves 20 provided in the tread portion 3. The plurality of blocks 30 are delimited by the narrow grooves 20.

  FIG. 3 is a plan view showing an example of the block 30 according to the present embodiment. FIG. 3 shows one block 30 among the plurality of blocks 30 provided in the tread portion 3. As described above, the ground plane 2 includes the surface of the block 30. In the following description, the surface of the block 30 is appropriately referred to as a ground plane 2.

  The block 30 has a ground plane 2 and an edge 10 that defines the outline of the ground plane 2. A narrow groove 20 is provided around the block 30. An edge 10 of the ground contact surface 2 of the block 30 is defined by a narrow groove 20 provided in the tread portion 3. The outer shape of the ground plane 2 is defined by the narrow groove 20. The ground plane 2 is disposed inside the edge 10.

  The edge 10 of the block 30 includes a first line 51, a second line 52, a first corner 61 provided between one end of the first line 51 and one end of the second line 52, and a third line 53. And the fourth line 54, the second corner 62 provided between one end of the third line 53 and one end of the fourth line 54, the other end of the first line 51, and the third line 53. Between the fifth line 55 connecting the end, the sixth line 56 connecting the other end of the second line 52 and the other end of the fourth line 54, and between the third line 53 and the fifth line 55. A third corner 63 provided and a fourth corner 64 provided between the fourth line 54 and the sixth line 56 are included.

  In the present embodiment, the edge 10 of the block 30 includes a fifth corner 65 provided between the other end of the first line 51 and the fifth line 55, and the other end of the second line 52 and the sixth line 56. And a sixth corner 66 provided between the first corner 66 and the second corner 66.

  In this embodiment, the block 30 is substantially hexagonal.

  In the present embodiment, the first line 51 is linear. The second line 52 is linear. The third line 53 is linear. The fourth line 54 is linear. The fifth line 55 is linear. The sixth line 56 is linear.

  In the present embodiment, the first line 51 and the third line 53 are parallel. The second line 52 and the fourth line 54 are parallel. The fifth line 55 and the sixth line 56 are parallel.

  In the present embodiment, the dimension (length) of the first line 51 and the dimension (length) of the second line 52 are substantially equal. The dimension (length) of the third line 53 and the dimension (length) of the fourth line 54 are substantially equal. The dimension (length) of the fifth line 55 and the dimension (length) of the sixth line 56 are substantially equal.

  The length of the first line 51 is the distance between one end and the other end of the first line 51. The same applies to the second line 52, the third line 53, the fourth line 54, the fifth line 55, and the sixth line 56.

  In the present embodiment, the dimensions of the first line 51, the second line 52, the third line 53, the fourth line 54, the fifth line 55, and the sixth line 56 are 5 mm or more and 25 mm or less.

  The first corner 61 is angular. The second corner 62 is angular. The third corner 63 is angular. The fourth corner 64 is angular. The fifth corner 65 is angular. The sixth corner 66 is angular.

  The first corner 61 protrudes outward. The first corner 61 protrudes outward with respect to the center (centroid) of the ground plane 2. The second corner 62 is recessed inward. The second corner 62 is recessed inward with respect to the center of the ground plane 2.

  The angle θ1 formed by the first line 51 and the second line 52 is not less than 40 degrees and not more than 160 degrees. The angle θ2 formed by the third line 53 and the fourth line 54 is not less than 200 degrees and not more than 320 degrees. An angle θ3 formed by the third line 53 and the fifth line 55 is smaller than 90 degrees. An angle θ4 formed by the fourth line 54 and the sixth line 56 is smaller than 90 degrees. The angle θ5 formed by the first line 51 and the fifth line 55 is greater than 90 degrees. The angle θ6 formed by the second line 52 and the sixth line 56 is greater than 90 degrees.

  In the present embodiment, the sum of the angle θ1 and the angle θ2 is 360 degrees. The angle θ3 and the angle θ4 are equal. The angle θ5 and the angle θ6 are equal.

  FIG. 4 is an enlarged plan view of a part of the tread portion 3 according to the present embodiment. In the present embodiment, a block group 40 is defined by a plurality of blocks 30 adjacent via the narrow groove 20. FIG. 4 shows one block group 40.

  As shown in FIG. 4, in the present embodiment, one block group 40 is defined by three blocks 30. That is, in the present embodiment, the block group 40 includes three blocks 30. In the following description, each of the three blocks 30 is appropriately referred to as a first block 31, a second block 32, and a third block 33.

  The external shape of the ground plane 2 of the first block 31, the external shape of the ground plane 2 of the second block 32, and the external shape of the ground plane 2 of the third block 33 are the same. In the present embodiment, the angle θ1 is about 120 degrees. The angle θ2 is about 240 degrees.

  FIG. 5 is a diagram showing the narrow grooves 20 with emphasis on one block group 40. As shown in FIGS. 4 and 5, the plurality of blocks 30 (31, 32, 33) of the block group 40 are arranged around a virtual point R set inside the narrow groove 20. The plurality of blocks 30 (31, 32, 33) of the block group 40 are arranged so that each first corner 61 faces the virtual point R around the virtual point R set inside the narrow groove 20. The The first block 31, the second block 32, and the third block 33 are arranged around the virtual point R at equal intervals.

  As shown in FIG. 5, the narrow groove 20 includes the first narrow groove 21 disposed between the first line 51 of the first block 31 and the second line 52 of the second block 32, and the second block 32. Between the 2nd fine groove 22 arrange | positioned between the 1st line 51 and the 2nd line 52 of the 3rd block 33, and the 1st line 51 of the 3rd block 33, and the 2nd line 52 of the 1st block 31 And the third narrow groove 23 disposed in the. The first fine groove 21, the second fine groove 22, and the third fine groove 23 intersect. The imaginary point R is set at a portion where the first fine groove 21, the second fine groove 22, and the third fine groove 23 intersect.

  In the following description, a portion where the first fine groove 21, the second fine groove 22, and the third fine groove 23 intersect is appropriately referred to as an intersection space. The intersection space is a space inside the narrow groove 20. The virtual point R is set inside the intersection space.

  At least a part of the intersection space is defined by the first corner 61 of the first block 31, the first corner 61 of the second block 32, and the first corner 61 of the third block 33. The first block 31 is arranged so that the first corner 61 of the first block 31 faces the intersection space including the virtual point R. The second block 32 is arranged so that the first corner 61 of the second block 32 faces the intersection space including the virtual point R. The third block 33 is arranged so that the first corner 61 of the third block 33 faces the intersection space including the virtual point R. The plurality of blocks 30 (31, 32, 33) of the block group 40 are arranged so that the first corners 61 are close to each other and face each other.

  FIG. 6 is an enlarged plan view of a part of the tread portion 3 according to the present embodiment. As shown in FIG. 6, a plurality of block groups 40 are provided in the tread portion 3. The plurality of block groups 40 are arranged adjacent to each other. In FIG. 6, in order to make the drawing easy to see, the narrow groove 20 that defines the outer shape of the block group 40 is shown thick, but the width of the narrow groove 20 is uniform throughout the tread portion 3.

  As shown in FIG. 6, the tread portion 3 includes a block 37 surrounded by a plurality of block groups 40. The block 37 does not belong to the block group 40. In the example shown in FIG. 6, the outer shape of the ground contact surface 2 of the block 37 is a regular hexagon.

  FIG. 7 is a diagram in which three block groups 40 are extracted from the plurality of block groups 40. In the following description, each of the three block groups 40 is appropriately referred to as a first block group 41, a second block group 42, and a third block group 43.

  The first block group 41 and the second block group 42 are adjacent to each other. The second block group 42 and the third block group 43 are adjacent to each other. The third block group 43 and the first block group 41 are adjacent to each other.

  The outer shape of the first block group 41, the outer shape of the second block group 42, and the outer shape of the third block group 43 are the same.

  As shown in FIG. 7, the fourth corner 64 of the block 30 (third block 33) of the first block group 41 and the third corner 63 of the block 30 (first block 31) of the second block group 42 face each other. To be arranged. That is, the fourth corner 64 of the first block group 41 and the third corner 63 of the second block group 42 are arranged so as to face each other with the narrow groove 20 therebetween.

  The fourth corner 64 of the block 30 (first block 31) of the second block group 42 and the third corner 63 of the block 30 (second block 32) of the third block group 43 are arranged to face each other. That is, the fourth corner 64 of the second block group 42 and the third corner 63 of the third block group 43 are arranged so as to face each other through the narrow groove 20.

  The fourth corner 64 of the block 30 (second block 32) of the third block group 43 and the third corner 63 of the block 30 (third block 33) of the first block group 41 are arranged to face each other. That is, the fourth corner 64 of the third block group 43 and the third corner 63 of the first block group 41 are arranged so as to face each other through the narrow groove 20.

  Thus, in the present embodiment, two adjacent block groups 40 in the tread portion 3 are divided into the third corner 63 of the block 30 of one block group 40 and the fourth corner of the block 30 of the other block group 40. 64 is arranged to face each other.

  In the present embodiment, the block group 40 includes three blocks 30 (31, 32, 33) arranged around the virtual point R. One block group 40 has three third corners 63. One block group 40 has three fourth corners 64.

  As shown in FIG. 6 and the like, a plurality of other block groups 40 are arranged around a certain block group (specific block group) 40. Each of the plurality of other block groups 40 is arranged adjacent to the specific block group 40. In the present embodiment, all of the three third corners 63 included in the specific block group 40 face the fourth corners 64 included in the other block group 40. All of the four fourth corners 64 included in the specific block group 40 face the third corners 63 included in the other block group 40.

  As described above, according to the present embodiment, the edge 10 of the block 30 that defines the outer shape of the ground plane 2 has the first corner 61 protruding outward and the second corner 62 recessed inward, Has anisotropy. Thereby, the tire 1 can obtain a high edge effect in each of driving, braking, and turning.

  Further, according to the present embodiment, the block group 40 is defined by the plurality of blocks 30 that are adjacent via the narrow groove 20. The block group 40 is defined by a plurality of blocks 30 arranged around the virtual point R set inside the intersecting space of the narrow grooves 20. The blocks 30 are arranged such that the first corner 61 faces the virtual point R. In other words, the plurality of blocks 30 of the block group 40 are arranged so that the first corners 61 are close to each other and face each other. Thereby, the edge 10 of the block 30 which has anisotropy is arrange | positioned so that it may face in various directions. Therefore, even if forces in various directions act on the tread portion 3, the tire 1 can obtain a high edge effect. Therefore, the tire 1 can improve the performance on ice in each of driving, braking, and turning.

  Further, the blocks 30 of the block group 40 are adjacent to each other through the narrow groove 20. Therefore, even if a force acts on a certain block 30 among the plurality of blocks 30 and the block 30 is about to fall down, the block 30 is supported by the adjacent block 30. Thereby, falling of the block 30 is suppressed. By suppressing the collapse of the block 30, the performance on the ice of the tire 1 can be improved in each of driving, braking and turning.

  In the present embodiment, a plurality of block groups 40 are provided in the tread portion 3 so as to be adjacent to each other. Of the two adjacent block groups 40, the third corner 63 of the block 30 of one block group 40 is arranged to face the fourth corner 64 of the block 30 of the other block group 40. Two adjacent block groups 40 are arranged such that the third corner 63 of one block group 40 and the fourth corner 64 of the other block group 40 are close to each other and face each other. Thereby, the plurality of block groups 40 are arranged so as to be densely arranged, and the plurality of blocks 30 are arranged so as to be densely arranged. As a result, a higher edge effect is obtained, and the collapse of the block 30 is sufficiently suppressed. Therefore, the on-ice performance of the tire 1 can be significantly improved in each of driving, braking, and turning.

  In the present embodiment, the edge 10 of the block 30 includes a fifth corner 65 provided between the other end of the first line 51 and the fifth line 55, and the other end of the second line 52 and the fifth line 55. And a sixth corner 66 provided between the six lines 56. Thereby, even if forces in various directions act on the tread portion 3 due to the six lines and the six corners, the tire 1 can obtain a high edge effect. Therefore, the tire 1 can improve the performance on ice in each of driving, braking, and turning.

  In the present embodiment, the first line 51 and the third line 53 are parallel, and the second line 52 and the fourth line 54 are parallel. In the present embodiment, the fifth line 55 and the sixth line 56 are parallel. Thereby, a high edge effect is obtained and the performance on ice is improved.

  In the present embodiment, the dimension of the first line 51 and the dimension of the second line 52 are substantially equal, and the dimension of the third line 53 and the dimension of the fourth line 54 are substantially equal. Thereby, high on-ice performance can be obtained by the block 30 having a line-symmetric outer shape. Further, the blocks 30 can be densely packed.

  In the present embodiment, the block group 40 includes three blocks 30 arranged around the virtual point R, and a plurality of other block groups 40 are arranged around the specific block group 40. All of the three third corners 63 included in the specific block group 40 are opposed to the fourth corner 64 of the other block group 40, and all of the three fourth corners 64 included in the specific block group 40 are the other It faces the third corner 63 of the block group 40. Thereby, it arrange | positions so that the some block group 40 may be crowded, and while being able to obtain a high edge effect, the fall of the block 30 is suppressed.

  In the present embodiment, the dimensions of the first line 51, the second line 52, the third line 53, the fourth line 54, the fifth line 55, and the sixth line 56 are 5 mm or more and 25 mm or less. Thereby, the fall of the rigidity of the block 30 and the fall of the edge effect are suppressed. If the dimension is smaller than 5 mm, the rigidity of the block 30 is lowered, and as a result, the performance on ice may be lowered. When the dimension is larger than 25 mm, a sufficient edge effect cannot be obtained, and as a result, the performance on ice is lowered.

  In the present embodiment, the angle θ1 formed by the first line 51 and the second line 52 is not less than 40 degrees and not more than 160 degrees, and the angle θ2 formed by the third line 53 and the fourth line 54 is 200. More than 320 degrees and less. Thereby, the fall of the block 30 and the fall of the edge effect are suppressed. When the angle θ1 formed by the first line 51 and the second line 52 is smaller than 40 degrees, the rigidity of the block 30 is locally reduced, and as a result, the possibility that the block 30 falls is increased. If the angle θ1 formed by the first line 51 and the second line 52 is larger than 160 degrees, the edge effect of the block 30 may be reduced. If the angle θ2 formed by the third line 53 and the fourth line 54 is larger than 320 degrees, the rigidity of the block 30 is locally reduced, and as a result, the possibility of the block 30 falling is increased. If the angle θ2 formed by the third line 53 and the fourth line 54 is smaller than 200 degrees, the edge effect of the block 30 may be reduced.

  Moreover, in this embodiment, the width | variety of the narrow groove 20 is 1 mm or more and 4 mm or less. Thereby, falling of the block 30 can be suppressed while maintaining the water removal effect of the tread portion 3. If the width of the narrow groove 20 is smaller than 1 mm, the water removal effect is lowered. When the width of the narrow groove 20 is larger than 4 mm, when a certain block 30 tries to fall down, it becomes difficult for the adjacent block 30 to support, and as a result, the block 30 falls down.

  In the present embodiment, the first line 51 and the third line 53 may be non-parallel. The second line 52 and the fourth line 54 may be non-parallel. The fifth line 55 and the sixth line 56 may be non-parallel. The same applies to the following embodiments.

  In the present embodiment, the dimension of the first line 51 and the dimension of the second line 52 may be different. The dimension of the third line 53 and the dimension of the fourth line 54 may be different. The same applies to the following embodiments.

Second Embodiment
A second embodiment will be described. In the following description, the same or equivalent components as those in the above-described embodiment are denoted by the same reference numerals, and the description thereof is simplified or omitted.

  FIG. 8 is a plan view showing an example of a block 30B according to the present embodiment. The edge 10B of the block 30B includes a first line 51, a second line 52, a first corner 61 provided between one end of the first line 51 and one end of the second line 52, and a third line 53. And the fourth line 54, the second corner 62 provided between one end of the third line 53 and one end of the fourth line 54, the other end of the first line 51, and the third line 53. Between the fifth line 55 connecting the end, the sixth line 56 connecting the other end of the second line 52 and the other end of the fourth line 54, and between the third line 53 and the fifth line 55. A third corner 63 provided; a fourth corner 64 provided between the fourth line 54 and the sixth line 56; and a fifth corner provided between the other end of the first line 51 and the fifth line 55. Corner 65, the other end of second line 52 and sixth line 56 It includes a sixth corner 66 provided between, the.

  The first line 51, the second line 52, the third line 53, the fourth line 54, the fifth line 55, and the sixth line 56 are each linear.

  The first line 51 and the third line 53 are parallel. The second line 52 and the fourth line 54 are parallel. The fifth line 55 and the sixth line 56 are parallel. The dimension of the first line 51 and the dimension of the second line 52 are substantially equal. The dimension of the third line 53 and the dimension of the fourth line 54 are substantially equal. The dimension of the fifth line 55 and the dimension of the sixth line 56 are substantially equal.

  The first corner 61, the second corner 62, the third corner 63, the fourth corner 64, the fifth corner 65, and the sixth corner 66 are each angular.

  The sum of the angle θ1 and the angle θ2 is 360 degrees. In the present embodiment, the angle θ1 is about 90 degrees. The angle θ2 is about 270 degrees. The angle θ3 and the angle θ4 are equal. The angle θ5 and the angle θ6 are equal.

  FIG. 9 is an enlarged plan view of a part of the tread portion 3B according to the present embodiment. In the present embodiment, a block group 40B is defined by a plurality of blocks 30B adjacent via the narrow groove 20. FIG. 9 shows one block group 40B.

  In the present embodiment, one block group 40B is defined by the four blocks 30B. That is, in the present embodiment, the block group 40B has four blocks 30B arranged around the virtual point R. The plurality of blocks 30 </ b> B of the block group 40 </ b> B are arranged so that each first corner 61 faces the virtual point R around the virtual point R set inside the narrow groove 20. In the following description, each of the four blocks 30B is appropriately referred to as a first block 31B, a second block 32B, a third block 33B, and a fourth block 34B.

  Of the four blocks 30B arranged around the virtual point R, the first corner 61 of the first block 31B, the second corner 62 of the first block 31B, the first corner 61 of the third block 33B, The second corner 62 of the three blocks 33B is arranged on the straight line L1.

  Of the four blocks 30B arranged around the virtual point R, the first corner 61 of the second block 32B, the second corner 62 of the second block 32B, the first corner 61 of the fourth block 34B, The second corner 62 of the four block 34B is arranged on the straight line L2.

  In the present embodiment, the straight line L1 and the straight line L2 are orthogonal to each other.

  FIG. 10 is an enlarged plan view of a part of the tread portion 3B according to the present embodiment. As shown in FIG. 10, a plurality of block groups 40B are provided in the tread portion 3B. The plurality of block groups 40B are arranged adjacent to each other. In FIG. 10, for the sake of clarity, the narrow groove 20 that defines the outer shape of the block group 40B is shown thick, but the width of the narrow groove 20 is uniform throughout the tread portion 3B.

  As shown in FIG. 10, the tread portion 3B has a block 38 surrounded by a plurality of block groups 40B. The block 38 does not belong to the block group 40B. In the example shown in FIG. 10, the outer shape of the ground plane 2 of the block 38 is a square.

  FIG. 11 is a diagram in which five block groups 40B are extracted from the plurality of block groups 40B. In the following description, each of the five block groups 40B is appropriately referred to as a first block group 41B, a second block group 42B, a third block group 43B, a fourth block group 44B, and a fifth block group 45B.

  In FIG. 11, the second block group 42B, the third block group 43B, the fourth block group 44B, and the fifth block group 45B are arranged around the first block group 41B. The first block group 41B and the second block group 42B are adjacent to each other. The first block group 41B and the third block group 43B are adjacent to each other. The first block group 41B and the fourth block group 44B are adjacent to each other. The first block group 41B and the fifth block group 45B are adjacent to each other.

  As shown in FIG. 11, the third corner 63 of the first block group 41 </ b> B and the fourth corner 64 of the second block group 42 </ b> B are opposed to each other through the narrow groove 20. The fourth corner 64 of the first block group 41B and the third corner 63 of the second block group 42B are opposed to each other through the narrow groove 20.

  The third corner 63 of the first block group 41B and the fourth corner 64 of the third block group 43B are opposed to each other through the narrow groove 20. The fourth corner 64 of the first block group 41B and the third corner 63 of the third block group 43B are opposed to each other through the narrow groove 20.

  The third corner 63 of the first block group 41B and the fourth corner 64 of the fourth block group 44B are opposed to each other through the narrow groove 20. The fourth corner 64 of the first block group 41B and the third corner 63 of the fourth block group 44B are opposed to each other through the narrow groove 20.

  The third corner 63 of the first block group 41B and the fourth corner 64 of the fifth block group 45B are opposed to each other through the narrow groove 20. The fourth corner 64 of the first block group 41B and the third corner 63 of the fifth block group 45B are opposed to each other through the narrow groove 20.

  Thus, also in this embodiment, the two block groups 40B adjacent in the tread portion 3B are divided into the third corner 63 of the block 30B of one block group 40B and the fourth corner of the block 30B of the other block group 40B. 64 is arranged to face each other.

  In the present embodiment, the block group 40B includes four blocks 30B (31B, 32B, 33B, 34B) arranged around the virtual point R. One block group 40 </ b> B has four third corners 63. One block group 40 </ b> B has four fourth corners 64.

  As shown in FIGS. 10 and 11, a plurality of other block groups 40B are arranged around one block group (specific block group) 40B. Each of the plurality of other block groups 40B is arranged adjacent to the specific block group 40B. In the present embodiment, all of the four third corners 63 included in the specific block group 40B are opposed to the fourth corners 64 included in the other block group 40B. All of the four fourth corners 64 included in the specific block group 40B are opposed to the third corners 63 included in the other block group 40B.

  As described above, also in the present embodiment, the tire 1 can obtain high performance on ice. In addition, the plurality of block groups 40B are arranged so as to be dense, and a high edge effect is obtained, and the collapse of the block 30B is suppressed.

<Third Embodiment>
A third embodiment will be described. In the following description, the same or equivalent components as those in the above-described embodiment are denoted by the same reference numerals, and the description thereof is simplified or omitted.

  FIG. 12 is a plan view showing an example of a block 30C according to the present embodiment. The edge 10 </ b> C of the block 30 </ b> C includes a first line 51, a second line 52, a first corner 61 provided between one end of the first line 51 and one end of the second line 52, and a third line 53. And the fourth line 54, the second corner 62 provided between one end of the third line 53 and one end of the fourth line 54, the other end of the first line 51, and the third line 53. Between the fifth line 55 connecting the end, the sixth line 56 connecting the other end of the second line 52 and the other end of the fourth line 54, and between the third line 53 and the fifth line 55. A third corner 63 provided; a fourth corner 64 provided between the fourth line 54 and the sixth line 56; and a fifth corner provided between the other end of the first line 51 and the fifth line 55. Corner 65, the other end of second line 52 and sixth line 56 It includes a sixth corner 66 provided between, the.

  The first line 51, the second line 52, the third line 53, the fourth line 54, the fifth line 55, and the sixth line 56 are each linear.

  The first line 51 and the third line 53 are parallel. The second line 52 and the fourth line 54 are parallel. The fifth line 55 and the sixth line 56 are parallel. The dimension of the first line 51 and the dimension of the second line 52 are substantially equal. The dimension of the third line 53 and the dimension of the fourth line 54 are substantially equal. The dimension of the fifth line 55 and the dimension of the sixth line 56 are substantially equal.

  The first corner 61, the second corner 62, the third corner 63, the fourth corner 64, the fifth corner 65, and the sixth corner 66 are each angular.

  The sum of the angle θ1 and the angle θ2 is 360 degrees. In the present embodiment, the angle θ1 is about 60 degrees. The angle θ2 is about 300 degrees. The angle θ3 and the angle θ4 are equal. The angle θ5 and the angle θ6 are equal.

  FIG. 13 is an enlarged plan view of a part of the tread portion 3C according to the present embodiment. In the present embodiment, a block group 40C is defined by a plurality of blocks 30C adjacent via the narrow groove 20. FIG. 13 shows one block group 40C.

  In the present embodiment, one block group 40C is defined by six blocks 30C. That is, in the present embodiment, the block group 40C has six blocks 30C arranged around the virtual point R. The plurality of blocks 30 </ b> C of the block group 40 </ b> C are arranged so that each first corner 61 faces the virtual point R around the virtual point R set inside the narrow groove 20. In the following description, each of the six blocks 30C is appropriately referred to as a first block 31C, a second block 32C, a third block 33C, a fourth block 34C, a fifth block 35C, and a sixth block 36C.

  Of the six blocks 30C arranged around the virtual point R, the narrow groove 21 separating the first block 31C and the second block 32C and the narrow groove 24 separating the fourth block 34C and the fifth block 35C are provided. It arrange | positions on the straight line La. Among the six blocks 30C arranged around the virtual point R, the narrow groove 22 that separates the second block 32C and the third block 33C and the narrow groove 25 that separates the fifth block 35C and the sixth block 36C are provided. It arrange | positions on the straight line Lb. Of the six blocks 30C arranged around the virtual point R, the narrow groove 23 separating the third block 33C and the fourth block 34C and the narrow groove 26 separating the sixth block 36C and the first block 31C are provided. It arrange | positions on the straight line Lc.

  Of the six blocks 30C arranged around the virtual point R, the first corner 61 of the first block 31C, the second corner 62 of the first block 31C, the first corner 61 of the fourth block 34C, The second corner 62 of the four block 34C is arranged on the straight line L1.

  Among the six blocks 30C arranged around the virtual point R, the first corner 61 of the second block 32C, the second corner 62 of the second block 32C, the first corner 61 of the fifth block 35C, and the first The second corner 62 of the five blocks 35C is arranged on the straight line L2.

  Of the six blocks 30C arranged around the virtual point R, the first corner 61 of the third block 33C, the second corner 62 of the third block 33C, the first corner 61 of the sixth block 36C, The 6th block 36C and the 2nd corner 62 are arrange | positioned on the straight line L3.

  FIG. 14 is an enlarged plan view of a part of the tread portion 3C according to the present embodiment. As shown in FIG. 14, a plurality of block groups 40C are provided in the tread portion 3C. The plurality of block groups 40C are arranged adjacent to each other. In FIG. 14, the narrow grooves 20 that define the outer shape of the block group 40 </ b> C are shown thicker to make the drawing easier to see, but the width of the narrow grooves 20 is uniform throughout the tread portion 3 </ b> C.

  As illustrated in FIG. 14, the tread portion 3C includes a block 39 surrounded by a plurality of block groups 40C. The block 39 does not belong to the block group 40C.

  As shown in FIG. 14, the plurality of block groups 40C are arranged so as to be adjacent to each other. A plurality of other block groups 40C are arranged around the specific block group 40C.

  Also in the example illustrated in FIG. 14, the two block groups 40C adjacent in the tread portion 3C include the third corner 63 of the block 30C of one block group 40C and the fourth corner 64 of the block 30C of the other block group 40C. Are arranged to face each other.

  In the present embodiment, the block group 40C includes six blocks 30C (31C, 32C, 33C, 34C, 35C, and 36C) arranged around the virtual point R. One block group 40 </ b> C includes six third corners 63. One block group 40 </ b> C has six fourth corners 64.

  A plurality of other block groups 40C are arranged around a certain block group (specific block group) 40C. Each of the plurality of other block groups 40C is arranged adjacent to a specific block group 40C. In the example illustrated in FIG. 14, four third corners 63 of the six third corners 63 included in the specific block group 40C face the fourth corners 64 of the other block group 40C. Of the four fourth corners 64 included in the specific block group 40C, the four fourth corners 64 face the third corner 63 of the other block group 40C.

  In the example illustrated in FIG. 14, the straight line L2 of one block group 40C and the straight line L2 of the other block group 40C among the two adjacent block groups 40C are arranged on the same straight line.

  Further, in the example shown in FIG. 14, the straight line Lc of one block group 40C and the straight line Lc of the other block group 40C among the two adjacent block groups 40C are arranged on the same straight line.

  As described above, also in the present embodiment, the tire 1 can obtain high performance on ice. Further, the plurality of block groups 40C are arranged so as to be dense, and a high edge effect is obtained, and the collapse of the block 30C is suppressed.

<Fourth embodiment>
A fourth embodiment will be described. In the following description, the same or equivalent components as those in the above-described embodiment are denoted by the same reference numerals, and the description thereof is simplified or omitted.

  This embodiment is a modification of the above-described third embodiment. 15 and 16 show examples of arrangement of the block group 40C according to the present embodiment. The block group 40C is the block group 40C described with reference to FIG.

  In the example shown in FIGS. 15 and 16, a plurality of other block groups 40C are arranged around a specific block group 40C. All of the six third corners 63 included in the specific block group 40C face the fourth corners 64 of the other block group 40C. All of the six fourth corners 64 of the specific block group 40C face the third corners 63 of the other block group 40C.

  In the example illustrated in FIG. 15, the straight line La of one block group 40C and the straight line La of the other block group 40C among the two adjacent block groups 40C are arranged on the same straight line. Of the two adjacent block groups 40C, the straight line Lb of one block group 40C and the straight line Lb of the other block group 40C are arranged on the same straight line. Of the two adjacent block groups 40C, the straight line Lc of one block group 40C and the straight line Lc of the other block group 40C are arranged on the same straight line.

  In the example shown in FIG. 16, the straight line L1 of one block group 40C and the straight line L1 of the other block group 40C among the two adjacent block groups 40C are arranged on the same straight line. Of the two adjacent block groups 40C, the straight line L2 of one block group 40C and the straight line L2 of the other block group 40C are arranged on the same straight line. Of the two adjacent block groups 40C, the straight line L3 of one block group 40C and the straight line L3 of the other block group 40C are arranged on the same straight line.

  Also in the example shown in FIGS. 15 and 16, the tire 1 can obtain high performance on ice. Further, the plurality of block groups 40C are arranged so as to be dense, and a high edge effect is obtained, and the collapse of the block 30C is suppressed.

<Fifth Embodiment>
A fifth embodiment will be described. In the following description, the same or equivalent components as those in the above-described embodiment are denoted by the same reference numerals, and the description thereof is simplified or omitted.

  FIG. 17 is a diagram illustrating an example of a block 30D according to the present embodiment. In the above-described embodiments, the first corner 61 to the sixth corner 66 are all angular. As shown in FIG. 17, the first corner 61 may include a curve. That is, the first corner 61 may be rounded. In addition to the first corner 61, at least one of the second corner 62, the third corner 63, the fourth corner 64, the fifth corner 65, and the sixth corner 66 may include a curve.

  FIG. 18 is a diagram illustrating an example of a block 30E according to the present embodiment. In the above-described embodiments, all of the first line 51 to the sixth line 56 are linear. As shown in FIG. 18, the third line 53 may include a curve, and the fourth line 54 may include a curve. Note that at least one of the first line 51, the second line 52, the fifth line 55, and the sixth line 56 may include a curve.

  FIG. 19 is a diagram illustrating an example of a block 30F according to the present embodiment. As shown in FIG. 19, the first line 51 and the fifth line 55 may be arranged on the same straight line, and the second line 52 and the sixth line 56 may be arranged on the same straight line. A block 30F shown in FIG. 19 is substantially rectangular. The block 30 </ b> F includes a first corner 61, a second corner 62, a third corner 63, and a fourth corner 64. In the example shown in FIG. 19, high on-ice performance can be obtained by the block 30F having four lines (sides).

  FIG. 20 is a diagram illustrating an example of a block 30G according to the present embodiment. As shown in FIG. 20, a seventh corner 67 may be provided on at least a part of the fifth line 55 that connects the other end of the first line 51 and the other end of the third line 53. An eighth corner 68 may be provided on at least a part of the sixth line 56 that connects the other end of the second line 52 and the other end of the fourth line 54.

  That is, in each of the above-described embodiments, as illustrated in FIG. 21, the edge of the block 30 </ b> X includes the first line 51, the second line 52, one end of the first line 51, and one end of the second line 52. A first corner 61, a third line 53, a fourth line 54, a second corner 62 provided between one end of the third line 53 and one end of the fourth line 54, Between the fifth line 55 forming the third corner 63 between the other end of the first line 51 and the third line 53, and between the other end of the second line 52 and the fourth line 54. And the sixth line 56 forming the fourth corner 64 may be included. The form of the fifth line 55 and the form of the sixth line 56 can be arbitrarily selected.

<Sixth Embodiment>
A sixth embodiment will be described. In the following description, the same or equivalent components as those in the above-described embodiment are denoted by the same reference numerals, and the description thereof is simplified or omitted.

  FIG. 22 is a diagram illustrating an example of a block 30H according to the present embodiment. As illustrated in FIG. 22, the block 30 </ b> H includes a sipe 71. The sipe 71 is formed so as to connect the fifth line 55 and the sixth line 56. The sipe 71 is linear.

  FIG. 23 is a diagram illustrating an example of a block 30I according to the present embodiment. As shown in FIG. 23, the block 30I has a sipe 72. The sipe 72 is formed so as to connect the fifth line 55 and the sixth line 56. The sipe 72 has a bent portion.

  The sipe 71 and the sipe 72 are grooves having a width of 0.4 mm or more and less than 1.0 mm, and are narrower than the above-described narrow groove 20.

  According to the present embodiment, the performance on ice can be further improved by the sipe 71 or the sipe 72.

(Example)
FIG. 24 is a diagram showing the results of a performance test of the tire 1 according to this embodiment. FIG. 24 shows the results of a performance test relating to the on-ice braking, on-ice turning, and on-snow braking of the tire 1.

  In the performance test, the tire 1 is mounted on a sedan type test vehicle having a displacement of 1000 [cc]. The size of the tire 1 is 195 / 65R15, and the air pressure of the tire 1 is 220 kPa. The test vehicle traveled on an ice board road surface and evaluated braking / driving performance and turning performance. Moreover, the test vehicle traveled on a snow-capped road surface and evaluated braking / driving performance. In the braking test, index evaluation was performed with a braking distance from 40 km / h as a reference (100) based on Conventional Example 1. This evaluation is preferable as the numerical value increases.

  In FIG. 24, a block group (no adjacency) means that a plurality of block groups are arranged apart from each other, although a block group is provided in the tread portion. The block group (with adjacent) means that a plurality of block groups are arranged adjacent to each other in the tread portion as described in the above embodiments.

In FIG. 24, the length of the line is the dimension of the first line 51 to the sixth line 56. θ1 is an angle formed by the first line 51 and the second line 52 . The narrow groove width is the width of the narrow groove 20.

  In FIG. 24, Conventional Example 1 is a tire having a tread pattern as shown in FIG. As shown in FIG. 25, the tire of Conventional Example 1 has a main groove 9. The outer shape of the block 301J is a quadrangle. In Conventional Example 1, the block group (40) does not exist. The dimension of the line (side) of the block 301J is 10 mm, and the width of the narrow groove 20 is 2 mm.

In FIG. 24, Conventional Example 2 is a tire having a tread pattern as shown in FIG. As shown in FIG. 26, the tire of Conventional Example 2 has a main groove 9. The outer shape of the block 302J is equivalent to the block 30 described with reference to FIG. The angle θ1 is 120 degrees. In Conventional Example 2, the first corners 61J of the plurality of blocks 302J face the same direction. In Conventional Example 2, the block group (40) does not exist. The block 302J has a line size of 10 mm, and the narrow groove 20 has a width of 2 mm.

Example 2 has a block group 40 as described in the above embodiments. In the second embodiment , the plurality of block groups 40 are arranged adjacent to each other. In Example 2 , the angle θ1 is 120 degrees. The width of the narrow groove 20 is 2 mm. The dimension of the line of Example 2 is 10 mm .

As shown in the test results, it can be seen that in the tire 1 of Example 2 , on-ice braking / driving performance, on-ice turning performance, and on-snow braking / driving performance are improved .

In Example 2 , it was confirmed that when the block was provided with sipes, the on-ice braking / driving performance, on-ice turning performance, and on-snow braking / driving performance were further improved.

DESCRIPTION OF SYMBOLS 1 Pneumatic tire 2 Ground contact surface 3 Tread part 4 Bead part 5 Side wall part 6 Carcass 7 Inner liner 8 Groove 9 Main groove 10 Edge 11 Bead core 12 Bead filler 14 Belt 15 Tread rubber 16 Side wall rubber 20 Narrow groove 21 First narrow Groove 22 2nd narrow groove 23 3rd narrow groove 24 4th narrow groove 25 5th narrow groove 26 6th narrow groove 30 Block 31 1st block 32 2nd block 33 3rd block 34 4th block 35 5th block 36 1st 6 blocks 37 connected blocks 40 block group 41 first block group 42 second block group 43 third block group 51 first line 52 second line 53 third line 54 fourth line 55 fifth line 56 sixth line 61 first Corner 62 second corner 63 third corner 64 fourth corner 65 fifth corner 66 sixth Corner 71 Sipe 72 Sipe AX Rotation axis CL Center line R Virtual point

Claims (18)

An edge defined by a narrow groove provided in the tread portion, and a block having a grounding surface disposed inside the edge;
A group of blocks defined by a plurality of the blocks adjacent via the narrow groove;
With
The edge of the block is
The first line;
The second line;
A first corner provided between one end of the first line and one end of the second line and protruding outward;
The third line;
The fourth line;
A second corner provided between one end of the third line and one end of the fourth line and recessed inward;
A fifth line connecting the other end of the first line and the other end of the third line;
A sixth line connecting the other end of the second line and the other end of the fourth line;
A third corner provided between the third line and the fifth line;
A fourth corner provided between the fourth line and the sixth line;
Including
The plurality of blocks of the block group are arranged around a virtual point set inside the narrow groove so that each of the first corners faces the virtual point,
The block group includes a first block group and a second block group adjacent to the first block group,
The first block group and the second block group face the narrow groove where the third corner of the block of the first block group and the fourth corner of the block of the second block group are common. And arranged to face each other through the narrow groove ,
Pneumatic tire. The edge of the block is
A fifth corner provided between the other end of the first line and the fifth line;
The pneumatic tire according to claim 1, further comprising a sixth corner provided between the other end of the second line and the sixth line. The first line and the third line are parallel;
The pneumatic tire according to claim 2, wherein the second line and the fourth line are parallel to each other.   The pneumatic tire according to claim 2 or 3, wherein the fifth line and the sixth line are parallel to each other. The block group has three blocks arranged around the virtual point,
A plurality of the second block groups are arranged around the first block group,
All of the three third corners of the first block group are opposed to the fourth corner of the second block group,
The pneumatic tire according to any one of claims 2 to 4, wherein all three of the fourth corners of the first block group are opposed to the third corner of the second block group. The block group has four blocks arranged around the virtual point,
A plurality of the second block groups are arranged around the first block group,
All of the four third corners of the first block group are opposed to the fourth corner of the second block group,
The pneumatic tire according to any one of claims 2 to 4, wherein all of the four fourth corners of the first block group are opposed to the third corner of the second block group. Of the four blocks arranged around the virtual point, the first corner of the first block, the second corner of the first block, the first corner of the third block, and the third block Are arranged on a first straight line,
Of the four blocks arranged around the virtual point, the first corner of the second block, the second corner of the second block, the first corner of the fourth block, and the fourth block Are arranged on a second straight line,
The pneumatic tire according to claim 6, wherein the first straight line and the second straight line are orthogonal to each other. The block group has six blocks arranged around the virtual point,
A plurality of the second block groups are arranged around the first block group,
Of the six third corners of the first block group, four of the third corners face the fourth corner of the second block group,
5. The four fourth corners out of the six fourth corners of the first block group are opposed to the third corner of the second block group, according to claim 2. Pneumatic tires. Among the six blocks arranged around the virtual point, the first corner of the first block, the second corner of the first block, the first corner of the fourth block, and the fourth block Are arranged on a first straight line,
The pneumatic tire according to claim 8, wherein the first straight line of the first block group and the first straight line of the second block group are arranged on the same straight line. The block group has six blocks arranged around the virtual point,
A plurality of the second block groups are arranged around the first block group,
All of the six third corners of the first block group are opposed to the fourth corner of the second block group,
The pneumatic tire according to any one of claims 2 to 4, wherein all of the six fourth corners of the first block group are opposed to the third corner of the second block group. Of the six blocks arranged around the virtual point, the narrow groove separating the first block and the second block and the narrow groove separating the fourth block and the fifth block are on the first straight line. Arranged,
The pneumatic tire according to claim 10, wherein the first straight line of the first block group and the first straight line of the second block group are arranged on the same straight line. Among the six blocks arranged around the virtual point, the first corner of the first block, the second corner of the first block, the first corner of the fourth block, and the fourth block Are arranged on a first straight line,
The pneumatic tire according to claim 10, wherein the first straight line of the first block group and the first straight line of the second block group are arranged on the same straight line.   The dimension of each of the first line, the second line, the third line, the fourth line, the fifth line, and the sixth line is 5 mm or more and 25 mm or less. A pneumatic tire according to claim 1. The angle formed by the first line and the second line is not less than 40 degrees and not more than 160 degrees,
The pneumatic tire according to any one of claims 2 to 13, wherein an angle formed by the third line and the fourth line is not less than 200 degrees and not more than 320 degrees. The first line and the fifth line are arranged on the same straight line,
The pneumatic tire according to claim 1, wherein the second line and the sixth line are arranged on the same straight line. The dimension of the first line and the dimension of the second line are substantially equal;
The pneumatic tire according to any one of claims 1 to 15, wherein a dimension of the third line and a dimension of the fourth line are substantially equal.   The pneumatic tire according to any one of claims 1 to 16, wherein a width of the narrow groove is 1 mm or more and 4 mm or less.   The pneumatic tire according to any one of claims 1 to 17, further comprising a sipe provided in the block.

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