JP6518573B2 - tire - Google Patents

Description

  The present invention relates to a tire capable of traveling on a snowy road, such as a studless tire.

  2. Description of the Related Art Conventionally, as a studless tire intended to exhibit performance on a snowy road, a configuration using a composite land portion row configured by a plurality of land portion rows extending in the tire circumferential direction is known.

  For example, in the studless tire disclosed in Patent Document 1, longitudinal grooves extending obliquely with respect to the circumferential direction of the tire are intermittently formed between land portion rows constituting a composite land portion row (intermediate land portion). It is done. Further, in the composite land portion row, there are formed lateral grooves which extend obliquely with respect to the tire width direction and one ends in the land portion row. Moreover, several sipe is formed in the land part block which comprises a land part row | line | column.

  According to such a studless tire, the traction and braking performance on the icy and snow road are improved by the increase of the edge component in the tire width direction due to the lateral grooves, and the compound land portion row (intermediate land portion sandwiched between the lateral grooves and the longitudinal grooves The sharp corner of the) is not caught against the road surface at the time of cornering, and the cornering performance is also improved.

Japanese Patent Application Publication No. 2003-146016

  With studless tires, it is known that by increasing the number of sipes formed on land blocks, it is possible to increase the edge components that scratch the road surface and to improve braking performance on snowy and snowy roads, particularly on ice. .

  On the other hand, when the number of sipes formed in the land block increases, the rigidity of the land block (block stiffness) decreases, which hinders other performance improvements. When the block stiffness decreases, there is also a decrease in the braking performance on the icy road surface as described above, but there is a problem that the wear resistance performance particularly on a dry road surface significantly decreases.

  Specifically, when the number of sipes formed in the land block increases, the block stiffness of the entire land block is significantly reduced, so the end on the kicking side of the land block during acceleration, braking, etc. It is easy for the unit to lift up without touching the road surface. As a result, the wear of the land block progresses and the tire life is shortened.

  In addition, in winter tires such as studless tires, it is important to be able to reliably stop on the surface of ice, that is, the performance on ice in the circumferential direction of the tire, which is required when braking on the surface of ice. Since the performance on ice is improved by forming sipes in land blocks, the performance on ice has been improved by forming as many sipes as possible in one land block.

  For example, circumferential edges of land blocks that receive input in the tire circumferential direction at the time of braking, by making adjacent sipes face each other in the tire circumferential direction and make them parallel as much as possible in parallel with the tire width direction in which edge effects appear The number of sipes is increased as the side wall and the sipe are parallel to each other and the side wall and the sipe are as close as possible.

  Conventionally, as described above, the edge effect by the sipe edge is improved by forming the sipe in the closest state to the land block by making the sipe interval as small as possible.

  In addition, the pitch length which is the dimension in the tire circumferential direction of the pitch of the land portion block which is one basic unit of the tread pattern continuously repeated in the tire circumferential direction, and the circumferential direction dimension of the land portion block are increased. By improving the rigidity of the land block (block stiffness) and suppressing the land block collapse, the ground contact area is increased, and the performance on ice and the wear resistance are improved.

  However, the sipe density in the land block has already increased to the limit, and the sipe interval could not be reduced further. Even if the pitch length is increased and the circumferential dimension of the land block is increased, block stiffness is reduced if the land block is divided too finely by sipes.

  Furthermore, since the pitch length and the circumferential dimension of the land block increase, and the pitch in the contact length and the number of land blocks decrease, when the number is further decreased, the land block circumference is reduced. There is a problem that the dimension of the direction becomes too large, the area of the lug groove decreases and the drainage performance can not be secured, and the block edge component due to the lug groove can not be exhibited. The conventional tire as described above has not been able to solve such a problem.

  Therefore, the present invention has been made in view of such a situation, and the performance on an icy road surface and the dry road surface are achieved using a composite land portion row constituted by a plurality of land portion rows extending in the tire circumferential direction. It is an object of the present invention to provide a tire capable of traveling on a snowy road including an ice road surface such as a studless tire, which is compatible with performance, particularly wear resistance performance, in a higher dimension.

  The inventors of the present invention have studied the relationship between the vehicle characteristics and the contact state of the tire surface with regard to the improvement of the performance on ice at the time of braking, and as a result, the antilock brake system is In the case of a vehicle equipped with (ABS), the tread contact surface of the tire in contact with the ice surface is constantly updated without locking the wheel at the time of braking. It was found that there was little opportunity for the water film to intervene between the road surface and the tire surface when traveling on the road.

  Based on such findings, it has been found that, in the case of an ABS-equipped vehicle, securing a larger ground contact area is more effective for obtaining on-ice performance than improving the edge effect. Then, the inventors found out the following technical ideas as a result of earnestly examining from the viewpoint of the composition (tread pattern) of a tire about improvement of the performance on ice at the time of braking.

  First, the block stiffness can be improved by increasing the sipe interval. As a result, the ground contact area is improved by suppressing the falling of the land block, the force for pressing the block edge and the sipe edge against the road surface is improved, and the edge effect is improved. Also, as a result, the wear resistance performance is improved.

  In the present invention, the block stiffness means the block stiffness in the tire circumferential direction which is necessary when braking the road surface on ice unless otherwise noted.

  Here, when the sipe interval is increased, the number of sipe formed in the land block decreases, so the edge effect by the sipe edge decreases. Therefore, by further reducing the pitch length of the land block, the number of blocks per tire circumference is increased, and instead of the reduced sipe edge effect, the edge effect by the block edge having a larger edge effect is improved. To improve the total edge effect.

  That is, by increasing the sipe interval and reducing the pitch length of the land block, the block rigidity is improved, and the ground area is improved by suppressing the falling of the land block. In addition, the wear resistance performance is improved while the overall edge effect is improved by the improvement of the force pressing the block edge and the sipe edge against the road surface and the improvement of the block edge.

  As a result, the braking performance on the icy road surface and the performance on the dry road surface, particularly the wear resistance performance, can be compatible at a higher level.

  Therefore, in one aspect of the present invention, a circumferential groove extending in the circumferential direction of the tire and a lug groove extending in the width direction of the tire are formed, divided by the circumferential groove and the lug groove, and along the circumferential direction of the tire It is a tire provided with the compound land part line constituted by the 1st land part line and the 2nd land part line provided, and the 1st land part line and the 2nd land part line adjoin in the width-of-tire direction. The first land portion row is constituted by a first block, the second land portion row is constituted by a second block, and the first block is inclined relative to the tire width direction, and the second land portion A first inclined groove is formed in the column side wall, and the second block is inclined in the same direction as the first inclined groove and opened in the side wall opposite to the first land row side. Two inclined grooves are formed, and one end of the first inclined groove is in the first block. A first end sloped groove that terminates, the second sloped groove is a second end sloped groove whose one end terminates in the second block, and the second block that is adjacent to the first block in the tire width direction There is formed a transverse inclined groove which is inclined in the same direction as the first end inclined groove and which separates the adjacent second block, and the first end inclined groove in the contact surface with the road surface of the tire, The total area of the second end inclined groove and the transverse inclined groove is defined as a groove total area S1, and from one end of the composite land portion row in the tire width direction to the other end of the composite land portion row in the tire width direction When the total area of the land portion and the groove portion up to the portion is a combined land portion row total area S2, S1 / S2 is 0.05 or more and 0.25 or less.

  In one aspect of the present invention, the first block and the second block are formed with a plurality of sipes that extend in an inclined manner with respect to the tire width direction, and the circumference of the sipes adjacent in the tire circumferential direction in the first block The spacing in the direction may be 3.3 mm or more and 10.0 mm or less, and the spacing in the circumferential direction of the sipes adjacent to the tire circumferential direction in the second block may be 4.4 mm or more and 10.0 mm or less.

  In one aspect of the present invention, the negative rate of the first block may be 8.9% or more and 20.7% or less, and the negative rate of the second block may be 11.8% or more and 27.4% or less.

  In one aspect of the present invention, an average negative ratio of the first block and the second block adjacent to the first block in the tire width direction may be 13.2% or more and 30.8% or less.

  In one aspect of the present invention, the first block and the second block are formed with a plurality of sipes extending in an inclined manner with respect to the tire width direction, and an inclination angle of the sipes with respect to the tire width direction in the second block The inclination angle of the second end inclined groove and the inclination angle of the cross inclined groove may be equal to or greater than the inclination angle of the sipe with respect to the tire width direction in the first block and the inclination angle of the first end inclined groove.

  In one aspect of the present invention, the first end sloped groove, the second end sloped groove, and the cross sloped groove may be inclined in a direction opposite to the sipe with respect to the tire width direction.

  In one aspect of the present invention, the first block is formed with a notched groove opening on a side wall opposite to the second land portion row side and in the tire width direction, and an extension along the crossing inclined groove The first end inclined groove and the notch groove may be located.

  In one aspect of the present invention, at least a part of the composite land portion row may be provided in a center region including a tire equator line.

  According to the tire described above, the performance on an icy road surface and the performance on a dry road surface, in particular, the wear resistance performance can be further enhanced while using a composite land portion row constituted by a plurality of land portion rows extending in the tire circumferential direction. Can be compatible with

FIG. 1 is an overall schematic perspective view of a pneumatic tire 10. FIG. 2 is a partially enlarged perspective view of the pneumatic tire 10. FIG. 3 is a partial plan development view of the tread 20. FIG. FIG. 4 is a partially enlarged plan view of the V-shaped land portion row 100. As shown in FIG. FIG. 5 is a partially enlarged plan view of the V-shaped land portion block 101 constituting the V-shaped land portion row 100. FIG. 6 is a partially enlarged plan view of the central land portion row 200. As shown in FIG. FIGS. 7A and 7B are explanatory views of the rotational moment generated in the land portion block 210 and the rotational moment generated in the conventional land portion block 210P. FIG. 8 is a partially enlarged plan view of the shoulder land portion row 300in. FIG. 9 is an enlarged perspective view of the land block 310 constituting the shoulder land row 300in. FIG. 10 is a diagram showing the definition of various dimensions of the V-shaped land portion row 100. As shown in FIG. FIG. 11 is a diagram showing the definition of various dimensions of the central land portion row 200. As shown in FIG. FIG. 12 is a diagram showing the definition of various dimensions of the shoulder land portion row 300 in. FIG. 13 is a partial plan development view of a pneumatic tire 10A in which a pitch different from that of the pneumatic tire 10 shown in FIGS. 1 to 12 is set.

  Hereinafter, embodiments will be described based on the drawings. In addition, the same or similar reference numerals are given to the same functions or configurations, and the description thereof is appropriately omitted.

(1) Overall Schematic Configuration of Tire FIG. 1 is an overall schematic perspective view of a pneumatic tire 10 according to the present embodiment. FIG. 2 is a partially enlarged perspective view of the pneumatic tire 10. 1 and 2, illustration of a part of the pattern (tread pattern) formed on the tread 20 is omitted. FIG. 3 is a partial plan development view of the tread 20. FIG.

  As shown in FIGS. 1 to 3, the pneumatic tire 10 is a tire corresponding to traveling on a snowy road, particularly a road surface on ice, so-called studless tire. The pneumatic tire 10 has no designation of the rotational direction, but defines a row of shoulder land portions that should be positioned inside (vehicle hub side) and outside when the vehicle is mounted (see FIG. 2).

  The tread 20 of the pneumatic tire 10 is provided with a plurality of land portion rows in contact with the road surface. Specifically, the tread 20 is provided with a V-shaped land portion row 100, a central land portion row 200, and a shoulder land portion row 300 in and 300 out.

  The V-shaped land portion row 100 is provided offset from the position of the tire equator line CL (not shown in FIGS. 1 and 2, see FIG. 3). Specifically, the V-shaped land portion row 100 is provided on the tread end side with respect to the tire equator line CL.

  The central land portion row 200 is provided adjacent to the V-shaped land portion row 100 and at a position including the tire equator line CL.

  The shoulder land portion row 300out is provided adjacent to the central land portion row 200 and positioned outside the central land portion row 200 when the vehicle is mounted.

  The shoulder land portion row 300in is provided adjacent to the V-shaped land portion row 100 and positioned inside the V-shaped land portion row 100 when the vehicle is mounted.

  The tread 20 is formed with a plurality of circumferential grooves extending in the tire circumferential direction. Specifically, a circumferential groove 30 is formed between the V-shaped land portion row 100 and the central land portion row 200.

  A circumferential groove 40 is formed between the V-shaped land portion row 100 and the shoulder land portion row 300 in, and a circumferential groove 50 is formed between the central land portion row 200 and the shoulder land portion row 300 out. Ru.

  In addition, a circumferential groove 60 is formed between the land portion row 201 and the land portion row 202 constituting the central land portion row 200.

  Further, in the shoulder land portion row 300 out, a lug groove 70 extending in the tire width direction is formed, and in the shoulder land portion row 300 in, a lug groove 80 extending in the tire width direction is formed.

  In addition, the land part row mentioned above is comprised, and the element of the land part which can contact with a road surface is expressed as a land part block (or only a block).

  It is preferable that rubber (tread rubber) which constitutes such a tread 20 be foam rubber. The reason that foamed rubber is preferable is the ease of compressive deformation due to the effect that the rubber solid phase portion is replaced by the air phase portion by the inclusion of air holes in the foamed rubber.

  This improves the ground contact area by flexibility, removes the water film which greatly reduces the coefficient of friction μ on the ice surface by the foam holes in the tread surface, and sipe edge components or blocks by micro edges by scratching the block foam holes. The improvement of the edge effect similar to the edge component is remarkable.

  The tread rubber preferably has a two or more layer structure of surface rubber and internal rubber, and preferably uses foamed rubber as the surface rubber, and uses the internal rubber as non-foamed rubber or foamed rubber having a larger elastic modulus than the surface rubber. In addition, it is preferable to use surface rubber up to the radial depth position of the snow platform which shows the use limit due to wear, and to use internal rubber at a radially inner position rather than the snow platform.

  The foam rubber contains air holes inside, and has low elasticity, so that the rigidity of the entire land block (land block) is ensured by the rigidity of the inner rubber. The foaming rate is preferably 3 to 40%. When the foaming ratio is 40%, the elastic modulus of the foamed rubber is 60% with respect to the elastic modulus of the non-foamed rubber, and if the foaming ratio is larger than this, the elastic modulus of the foamed rubber is too low. This is because securing of rigidity can not be maintained even with the shape of the land block.

  When the foaming ratio is 3%, the elastic modulus of the foamed rubber is 97% with respect to the elastic modulus of the non-foamed rubber, and the block rigidity can be ensured. This is because it is not possible to exert the effect of removing the water film, removing the water film, or the edge. Optimally 12% to 32% is good. This is because block rigidity is secured, contact area by flexibility, water film removal, and edge effect are both achieved at a high level.

  Also, in winter tires such as studless tires, the elastic modulus of the tread rubber in contact with the road surface is softened to improve the coefficient of friction μ on the ice surface and improve the contact area due to flexibility, etc. In the tread rubber composition, if the amount of carbon added is reduced, the polymer is made to be low elastic in the temperature range of use, or the amount of added vulcanizing agent is reduced to suppress crosslinking, the wear performance is reduced. .

  In addition, when the amount of added oil is increased to lower the elasticity, in the product tire after vulcanization, the oil shifts to the outside of the tread rubber, and the elastic modulus becomes high and becomes hard due to aging with a half year to 1 year. I lose my sex. However, in the foamed rubber, since the flexibility is ensured by the internal air holes, the internal foam holes are not lost like oil due to the secular change.

  Furthermore, with respect to the compounding of the rubber solid phase portion other than rubber, the amount of carbon added can be increased, the elastic modulus in the polymer use temperature range can be increased, and the amount of added vulcanizing agent can be increased. This makes it possible to achieve extremely high elasticity with excellent wear performance without increasing the amount of oil added. Even with high elasticity, if the foaming ratio is 20%, it is replaced by air holes, and the elastic modulus of the foamed rubber can be 80% low elasticity rubber with respect to the elastic modulus of non-foamed rubber.

  In the pneumatic tire 10, the shape of the land block is greatly increased by utilizing the flexibility of the foamed rubber which can lower the elastic modulus so that the elastic modulus can be made lower than the elastic modulus of ordinary non-foamed rubber and the ease of compressive deformation. High rigidity.

  The elastic modulus of the rubber is 2.0 MPa to 5.0 MPa, preferably 2.3 MPa to 3.5 MPa. The rubber is preferably a foamed rubber. The foaming rate is 3% to 40%, and preferably 12% to 32%.

The elastic modulus (unit MPa) of rubber is a measured value at 23 ° C. defined in the JIS standard. The modulus of elasticity was measured using a spectrometer manufactured by Uejima Mfg. Co., Ltd. under the conditions of initial strain 2%, dynamic strain 1%, frequency 52 Hz, and the dynamic tensile storage elastic modulus E 'at 23 ° C. as the elastic modulus .
The larger the modulus of elasticity, the higher the modulus of elasticity.

  Here, the measured elastic modulus is the dynamic tensile storage elastic modulus E ′ in the dynamic tensile viscoelasticity test. However, also in tests other than the above, such as dynamic compression viscoelasticity test and dynamic shear viscoelasticity test, other dynamic viscoelasticity tests, their results are similar to the results of the dynamic tensile viscoelasticity test. The larger the ratio, the lower the elasticity.

  Therefore, the configuration of the elastic modulus of the tire described in the present embodiment is all satisfied in the dynamic viscoelasticity test under the above-described measurement conditions or the measurement conditions according thereto. The reason is that the rubber used in the tread portion of the tire has a Poisson's ratio close to 0.5 and there is very little volume change even if it is deformed, so the elastic modulus in tension, the elastic modulus in compression, the elastic modulus in shear Because it is proportional to the rate.

(2) Configuration of Tread 20 Next, the configuration of the tread 20 will be described. Specifically, the shapes of the V-shaped land portion row 100, the center land portion row 200, and the shoulder land portion row 300out provided in the tread 20 will be described.

(2.1) V-shaped land section row 100
FIG. 4 is a partially enlarged plan view of the V-shaped land portion row 100. As shown in FIG. The V-shaped land portion row 100 includes land portions blocks divided by the circumferential grooves 30 and 40 and the width direction sloping grooves 160 (lag grooves). Specifically, the V-shaped land portion row 100 is configured of a plurality of V-shaped land portion blocks 101 along the tire circumferential direction.

  The V-shaped land portion block 101 has a convex portion which is convex toward one of the tire circumferential direction and a concave portion which is similarly concave toward one of the tire circumferential direction, and is V-shaped in the tread surface view . Specifically, the V-shaped land portion block 101 is a V-shaped land portion block having a convex portion 110 and a concave portion 120. The V-shaped land portion block 101 means a block having a V-shaped or arrow-shaped shape in a tread surface view.

  In the tread surface view, the inclination angle θ1 (inclination direction) with respect to the tire width direction of the convex side wall portion 111 of the V-shaped land portion block 101 constituting the convex portion 110 is the tire width direction of the concave side wall portion 121 constituting the concave portion 120 Is the same as (in the same direction as) the inclination angle θ2 with respect to Similarly, the inclination angle θ3 (inclination direction) of the convex side wall portion 112 of the V-shaped land block 101 with respect to the tire width direction is the same as the inclination angle θ4 of the concave side wall portion 122 constituting the concave portion 120 with respect to the tire width direction Direction). In addition, the said inclination angle does not necessarily need to be the same, and "the same" or "the same direction" means that the difference of both inclination angles is less than 20 degrees (following, description of an inclination angle) Is similar).

  The inclination angles of the convex side wall 111, the sipe 130, and the end inclined groove 150 on the tire equatorial line CL side, and the inclination angles of the convex side wall 112 and the sipe 140 on the tread end side are one side with respect to the tire width direction. Is preferably in the range of 15 ° to 35 °, and the other side is in the range of 7 ° to 25 °. In the present embodiment, the angles of θ1, 2, 5, 6 (one side) shown in FIG. 4 are the same, and the angles of θ3, 4, 7, 8, 9 (the other side) are the same.

  If the inclination angle with respect to the tire width direction of the two side wall portions located on the convex portion 110 side of the V-shaped land block 101 is within such a range, the edge effect by the block edge and sipe edge in the tire circumferential direction is particularly enhanced. Because you can do it.

  The V-shaped land portion block 101 is formed with a plurality of sipes inclined with respect to the tire width direction. Specifically, sipes 130 and sipes 140 are formed. Although both the sipe 130 and the sipe 140 are inclined with respect to the tire width direction, the sipe 130 is inclined in the opposite direction to the sipe 140 with respect to the tire width direction.

  In the present embodiment, the sipes 130 and the sipes 140 are in a zigzag shape. Specifically, the sipe 130 and the sipe 140 are formed so as to be bent (one or more) in the extending direction in the tread surface view and to be linear in the tire radial direction. Alternatively, sipes 130 and sipes 140 may be formed to bend in both the extending direction and the tire radial direction. Alternatively, the sipes 130 and the sipes 140 may be formed so as to be bent in the tire radial direction and to be linear in the extending direction. Alternatively, the sipes 130 and the sipes 140 may be formed so as to be linear in the radial direction of the tire and linear in the extending direction thereof. Moreover, a sipe is a narrow groove closed within the contact surface of the land block, and the opening width of the sipe when not grounded is not particularly limited, but preferably 0.1 mm to 1.5 mm.

  Further, the V-shaped land portion block 101 is formed with a terminal inclined groove which is inclined with respect to the tire width direction. Specifically, on the tire equator line CL side of the V-shaped land portion block 101, a terminal inclined groove 150 is formed.

  Inclination with respect to the tire width direction means not parallel to the tire width direction but having a predetermined angle with respect to the tire width direction, but parallel to the tire circumferential direction (that is, It does not include the state where the angle with the tire width direction is 90 degrees).

  The inclination angle θ5 (inclination direction) of the end inclination groove 150 with respect to the tire width direction is the same as the inclination angle θ1 (inclination angle θ2) of the convex side wall portion 111 with respect to the tire width direction. Similarly, the inclination angle of the sipe 130 with respect to the tire width direction is also the same (the same direction) as the inclination angle θ1 (inclination angle θ2) with respect to the convex side wall portion 111 tire width direction. The same applies to the relationship between the recess side wall 121 and the sipe 130, the protrusion side wall 112 and the sipe 140, and the recess side wall 122 and the sipe 140.

  One end of the sipe 130 is open to the side wall 100 a of the V-shaped land portion block 101 in the tire width direction. On the other hand, the other end of the sipe 130 terminates in the V-shaped land block 101. Specifically, the end 131 of the sipe 130 terminates within the V-shaped land block 101.

  Similarly, one end of the end inclined groove 150 opens to the side wall 100 a on the tire equator line CL side. On the other hand, the end 151 of the end slope groove 150 ends in the V-shaped land portion block 101.

  The circumferential dimension of the V-shaped land portion block 101 in the tire circumferential direction is larger than the widthwise dimension of the V-shaped land portion block 101 in the tire width direction. The circumferential dimension of the V-shaped land portion block 101 means the length of the longest portion of the V-shaped land portion block 101 in the tire circumferential direction, and more specifically, the “circumferential dimension shown in FIG. ". The widthwise dimension of the V-shaped land portion block 101 means the length between the side wall 100a and the side wall 100b, and is the same as the "widthwise dimension" shown in FIG.

  The plurality of sipes 140 formed in the V-shaped land portion block 101 includes a communication sipe in communication with the end inclined groove 150. Specifically, the sipe 140 includes the communication sipe 141.

  One end of the communication sipe 141, specifically, the end 141 a communicates with the end 151 that is the end portion of the end inclined groove 150. The other end of the communication sipe 141 opens in the side wall 100 b in the tire width direction of the V-shaped land portion block 101. The side wall 100 b is a side wall at the tread end side in the tire width direction of the V-shaped land portion block 101.

  In the tread surface view, the side wall 100c of the V-shaped land portion block 101 constituting the end portion (end portion 151) of the end inclined groove 150 is continued on the extension line of the communication sipe 141. The position of the end portion of the end inclined groove 150 is different from the position of the most convex portion 110 a of the convex portion 110 in the tire width direction.

  Further, the end inclined groove 150 extends in the same direction as the sipe 130 formed on the opening end side of the end inclined groove 150 rather than the most recessed portion 120 a of the recess 120. The sipe 130 is formed on the opening end side of the end inclined groove 150 rather than the most recessed portion 120 a. The sipe 140 is formed closer to the end (end 151) of the end inclined groove 150 than the most concave portion 120a.

  The most convex portion of the convex portion 110 and the most concave portion of the concave portion 120 mean a maximum convex point and a maximum concave point which are bending points of the convex portion 110 and the concave portion 120. The bending point of the convex portion 110 and the concave portion 120 is a trapezoidal shape of two places or a plurality of places, or the convex portion 110 and the concave portion 120 are curved in a trapezoidal shape and the maximum convex point and the maximum concave point are in the tire width direction When there is a range, it means the center position in the tire width direction of the range.

  In the present embodiment, the most convex portion 110a is located closer to the tread end than the most concave portion 120a.

  The length of the end slope groove 150 is the same as the length of the sipe 130 formed on the open end side of the end slope groove 150. The length of the end slope groove 150 is the dimension of the end slope groove 150 along the extension direction of the end slope groove 150. The length of the sipe 130 is the dimension of the sipe 130 along the extension direction of the sipe 130.

  The end inclined groove 150 is inclined and extends in the same direction as the sipe 130 formed on the tire equatorial line CL side with respect to the center of the V-shaped land portion block 101 in the tire width direction.

  The V-shaped land portion block 101 includes a V-shaped land portion block 101A (first block) and a V-shaped land portion block 101B (second block) adjacent in the tire circumferential direction. Thus, a plurality of V-shaped land portion blocks 101 are provided along the tire circumferential direction.

  Between the V-shaped land portion block 101A and the V-shaped land portion block 101B, a width direction inclined groove that is inclined with respect to the tire width direction is formed. Specifically, a width direction inclined groove 160 having one bend is formed between the V-shaped land portion block 101A and the V-shaped land portion block 101B.

  Specifically, the widthwise inclined groove 160 is formed by the inclined groove portion 161 (first inclined groove portion) located on one side in the tire width direction with reference to the bent portion 163 and the tire width direction with respect to the bent portion 163. And an inclined groove portion 162 (second inclined groove portion) positioned on the other side. The inclined groove portion 161 is positioned closer to the opening end side of the end inclined groove 150 than the bending portion 163, that is, on the tire equator line CL side. The inclined groove portion 162 is located closer to the end (end portion 151) of the end inclined groove 150 than the bending portion 163.

  The bent portion 163 is bent at the position of the convex portion 110 of the V-shaped land portion block 101A and the recessed portion 120 of the V-shaped land portion block 101B. That is, the bent portion 163 is bent at the positions of the convex portion 110 and the concave portion 120 offset in the tire width direction, and as a result, the circumferential direction dimension (groove length) of the width direction inclined groove 160 along the tire circumferential direction ) Are different in the tire width direction. Specifically, the inclined groove portion 161 and the inclined groove portion 162 have different dimensions, and the dimension of the inclined groove portion 161 is larger than the dimension of the inclined groove portion 162.

  Further, a straight line connecting the most convex portion 110 a and the most concave portion 120 a is a boundary between the inclined groove portion 161 and the inclined groove portion 162. A line segment connecting the center point in the tire circumferential direction on this boundary line and the center point in the tire circumferential direction of the end opposite to the boundary of the inclined groove portion 161, and on the opposite side of the boundary with the boundary of the inclined groove portion 162 A line segment connecting a center point of the end portion in the tire circumferential direction is referred to as a width direction dimension.

  The end inclined groove 150 is inclined and extends in the same direction as the inclined groove portion 161. The sipe 130 also extends in the same direction as the inclined groove portion 161. The sipe 140 extends in the same direction as the inclined groove portion 162.

  The V-shaped land portion block 101 is provided in a center region including the tire equator line CL or in a second region located on the outer side in the tire width direction of the center region.

  In the present embodiment, among land blocks divided by the circumferential groove and the lug groove, those located at the ground contact end are located adjacent to the inside of the shoulder land block and the shoulder land land block in the tire width direction. The second land part block and the second land part block adjacent to each other on the inner side in the tire width direction and including the position of the tire equator line CL is called a center land block.

  In addition, areas included in the center part land block, the second land block, and the shoulder land block are referred to as a center area, a second area, and a shoulder area.

  When the center land block is in one row in the tire width direction, the center region is the tire equator line CL, that is, 16 from the ground contact center in the tire width direction which is half the ground contact width (W) of the pneumatic tire 10. % Area (W / 2 × 0.16), shoulder area means 42% area (W / 2 × 0.42) from the ground end, and second area is located on the inner side of the shoulder area in the tire width direction, and the ground area It is a 42% area (W / 2 × 0.42) of the width (W).

  When the center land block row is adjacent in the tire width direction and has two or more rows, the center region is the tire equator line CL, that is, the tire width direction which is half the contact width (W) of the pneumatic tire 10 22% area (W / 2 × 0.22) from the center of contact in the ground, shoulder area means 39% area (W / 2 × 0.39) from the ground end, and the second area is the tire width direction inside of the shoulder area And is a 39% area (W / 2 × 0.39) of the ground contact width (W).

  In the case of a land block that spans a plurality of areas of the center area, the second area, and the shoulder area, the land block of the area having the larger area is used. For example, when the area which exists in a center area | region is larger than a 2nd area | region, it is set as a center part land part block.

  In addition, if it is difficult to distinguish the division position of the center land block, the second land land block, and the shoulder land land block due to the shape of the circumferential groove (land block), etc. The land blocks present are the center land blocks, the land blocks present in the second region the second land blocks, and the land blocks present in the shoulder region the shoulder land blocks.

  Further, the ground contact width (W) refers to the dimension in the tire width direction of the tread 20 which is in contact with the road surface when a regular load is applied to the pneumatic tire 10 set to the regular internal pressure. Similarly, the ground contact surface (ground contact area) means a portion of the tread 20 that contacts the road surface when a regular load is applied to the pneumatic tire 10 set to the regular internal pressure.

  The normal internal pressure is the air pressure corresponding to the maximum load capacity of JATMA (Japan Automobile Tires Association) YearBook, and the normal load is the maximum load capacity (maximum load) corresponding to the maximum load capacity of JATMA YearBook.

  The negative rate of the V-shaped land portion block 101 is 2.5% or more and 30% or less. The negative rate is preferably 2.5% to 12.5%.

  The negative ratio of the V-shaped land block 101 means that the area of the V-shaped land block 101 is the area including the end slope groove 150 and the notched recess 170 present in the V-shaped land block 101 (hereinafter the same). The ratio of the sum of the area of the end slope groove 150 and the notch recess 170 to this area. That is, the groove area ratio, which is the ratio of the total area of the groove portion to the contact area of the tire including the negative ratio of the entire pneumatic tire 10 and the area of the groove portion, is calculated for one land block. Since the sipe closes in the ground plane, the area is zero.

  In addition, the negative ratio of the V-shaped land portion train 100 is 6% or more and 36% or less. The negative ratio is preferably 8% to 23%.

  The negative ratio of the V-shaped land portion row 100 means the area between the side walls (side wall 100 a to side wall 100 b) on both sides in the tire width direction of the V-shaped land portion row 100. The area including the grooves 150 and the notched recesses 170 and the widthwise inclined grooves 160 is the ratio of the area of the end inclined grooves 150 and the notched recesses 170 and the widthwise inclined grooves 160 to the total area It is. Because the sipe closes in the ground plane, the area is zero.

  The ratio of the widthwise dimension of the end inclined groove 150 to the widthwise dimension (see FIG. 10) of the V-shaped land portion block 101 is 24% or more and 64% or less. The ratio is preferably 34% to 54%. Further, the ratio of the widthwise dimension of the V-shaped land portion block 101 to the tread width of the tire is 8% or more and 38% or less. In addition, it is preferable that the said ratio is 10%-25%.

  The ratio of the circumferential dimension of the end inclined groove 150 to the circumferential dimension (see FIG. 10) of the V-shaped land portion block 101 is 7% or more and 37% or less. The ratio is preferably 9% to 29%. The circumferential dimension of the end inclined groove 150 means the length of the end inclined groove 150 along the tire circumferential direction (see FIG. 10). Further, the width direction dimension of the end inclined groove 150 means the length of the end inclined groove 150 along the tire width direction (see FIG. 10). The same applies to the other groove portions hereinafter.

  The ratio of the circumferential dimension of the end inclined groove 150 to the width direction of the end inclined groove 150 is 2.5% or more and 20% or less. The ratio is preferably 3% to 10%.

  The side wall 100 b located at the tire width direction end of the V-shaped land portion block 101 is formed with a cutout recess that is recessed like the V-shaped land portion block 101 is cut out. Specifically, a notch recess 170 is formed in the V-shaped land portion block 101.

  The sipe 140 formed in the V-shaped land portion block 101 includes a communication sipe (communication sipe 142) in communication with the notch recess 170.

  The circumferential dimension (see FIG. 10) of the notch recess 170 along the tire circumferential direction becomes larger toward the end of the V-shaped land portion block 101 in the tire width direction, specifically, the side wall 100b.

  In the present embodiment, the notched recess 170 is a wedge-shaped wedge-shaped groove. However, the shape of the notched recess 170 is not limited to a wedge shape (triangle) that tapers toward the center of the V-shaped land portion block 101 in the tire width direction in the tread surface view. For example, the notch recess portion 170 may have a shape such as a semicircular shape (sector shape) or a rectangular shape whose corner portions are chamfered in a tread surface view so that the edge of the communication sipe 142 does not have an acute angle.

  FIG. 5 is a partially enlarged plan view of the V-shaped land portion block 101 including the communication sipe 142. As shown in FIG. 5, one side wall (side wall 100 d) of the V-shaped land portion block 101 forming the communication sipe 142 is one side wall of the V-shaped land portion block 101 forming the cutout recess 170 (wedge groove). (The side wall 100e) is connected. The side wall 100 d extends in the same direction as the communication sipe 142.

  Further, the other side wall (side wall 100f) of the V-shaped land portion block 101 forming the communication sipe 142 is continuous with the other side wall (side wall 100g) of the V-shaped land portion block 101 forming the wedge-shaped groove. The side wall 100 g extends in the opposite direction to the communication sipe 142 with respect to the tire width direction, that is, based on the tire width direction.

  The ratio of the area of the notch recess 170 to the area of the V-shaped land portion block 101 including the area of the notch recess 170 is 0.3% or more and 15% or less. In addition, it is preferable that the said ratio is 0.3%-7%.

The ratio of the widthwise dimension (see FIG. 10) of the notched recess 170 to the widthwise dimension of the V-shaped land portion block 101 is 9% or more and 38% or less. The ratio is preferably 9, 2% to 30%, and more preferably 11% to 26%. In addition, the ratio of the circumferential dimension of the notched recess 170 to the circumferential dimension of the V-shaped land block 101 is 3% or more and 23% or less. The ratio is preferably 3% to 13%. The ratio of the widthwise dimension of the notched recess 170 to the circumferential dimension of the notched recess 170 is 130% or more and 270% or less. In addition, the said ratio is 150%-230%. The notch recessed part 170 is formed in the side wall 100b by the side of the tread end part of the V-shaped land part block 101. FIG. The notch recess 170 is recessed toward the tire equator line CL, and the circumferential dimension of the notch recess 170 increases toward the tread end.

  The V-shaped land portion block 101 is formed on one side in the tire width direction with respect to the most convex portion 110a of the convex portion 110, and has a convex portion side wall portion 111 (convex portion first side wall portion) inclined with respect to the tire width direction And a convex side wall portion 112 (convex second side wall portion) which is formed on the other side in the tire width direction with respect to the most convex portion 110a of the convex portion 110 and which is inclined to the tire width direction.

  The sipe 130 formed on one side in the tire width direction, specifically, on the tire equator line CL side, extends in the same direction as the convex sidewall portion 111. On the other hand, the other side in the tire width direction, specifically, the sipe 140 formed on the tread end side extends in the same direction as the convex side wall portion 112.

  The protrusion side wall portion 111 is longer than the protrusion side wall portion 112. Specifically, the length along the sidewall surface of the convex sidewall portion 111 in the tread surface view is longer than the length along the sidewall surface of the convex sidewall portion 112 in the tread surface. Also, the sipe 130 is shorter than the sipe 140. Specifically, the length along the extension direction of sipe 130 (not including the amplitude due to the zigzag portion) is shorter than the length along the extension direction of sipe 140 (not including the amplitude due to the zigzag portion) .

  The V-shaped land portion block 101 is formed on one side in the tire width direction, more specifically, on the tire equator line CL side with respect to the most recessed portion 120a, and is a recessed side wall portion 121 inclined with respect to the tire width direction. 1 side wall portion) and the other side in the tire width direction with respect to the most recessed portion 120a, specifically, the recessed side wall portion 122 (recessed second side wall portion) formed on the tread end side and inclined with respect to the tire width direction And).

  The recessed side wall 121 is longer than the recessed side wall 122. Specifically, the length along the side wall surface in the tread surface view of the recessed side wall portion 121 is longer than the length along the side wall surface in the tread surface view of the recessed side wall portion 122. Further, the convex side wall portion 111 is longer than the concave side wall portion 121. Furthermore, the recessed side wall 122 is longer than the recessed side wall 121. Specifically, the length along the side wall surface in the tread surface view of the recessed side wall portion 122 is longer than the length along the side wall surface in the tread surface view of the recessed side wall portion 121.

  In the present embodiment, the inclination angle (inclination direction) of the protrusion side wall portion 111 and the inclination angle (inclination direction) of the recess side wall portion 121 are the same (the same direction).

  The most convex portion 110 a of the V-shaped land portion block 101 is offset from the center of the V-shaped land portion block 101 in the tire width direction in the tire width direction. The offset amount is preferably 2.5% to 22.5% of the widthwise dimension of the V-shaped land portion block 101.

  If the most convex portion 110a is disposed off center by 2.5% to 22.5% of the width of the V-shaped land block 101, the circumferential dimension of the widthwise inclined groove 160 on the tread end side is reduced, and the V-shaped land block By increasing the circumferential dimension of 101, the block stiffness on the tread end side is improved. Also, by increasing the circumferential dimension of the widthwise inclined groove 160 on the tire equator line CL side and decreasing the circumferential dimension of the V-shaped land block 101, the block rigidity is reduced, and V is made more V than on the tread end side. The land portion block 101 falls appropriately to improve the edge effect by the block edge and the sipe edge on the tire equator line CL side. Thereby, the block rigidity of the V-shaped land portion block 101 can be configured in a well-balanced manner, which contributes to the coexistence of the on-ice performance and the wear resistance performance.

  The circumferential dimension W1 along the tire circumferential direction of the inclined groove portion 161 located on one side in the tire width direction relative to the bent portion 163 is the tire circumference of the inclined groove portion 162 located on the other side in the tire width direction than the bent portion 163 It is larger than the circumferential dimension W2 along the direction. The circumferential dimension W1 and the circumferential dimension W2 mean the lengths of the inclined groove portion 161 and the inclined groove portion 162 along the tire circumferential direction, as with the circumferential dimensions of the other groove portions.

  The sipe 130 formed on one side in the tire width direction with respect to the bent portion 163, specifically, on the tire equatorial line CL side extends in the same direction as the inclined groove portion 161. On the other hand, the sipe 140 formed on the other side in the tire width direction with respect to the bent portion 163, specifically, on the tread end side extends in the same direction as the inclined groove portion 162.

  In addition, the sipe 140 includes a sipe that is wider than the sipe 130 in the tire width direction. Specifically, the sipes 140 and the communication sipes 141 shown in FIG. 4 are wider in the tire width direction than the sipes 130.

  The widthwise dimension, which is the dimension of the inclined groove portion 161 in the tire width direction, is larger than the widthwise dimension of the inclined groove portion 162. Further, the end portion 131 of the sipe 130 terminates on the end side in the tire width direction with respect to the most convex portion 110 a of the convex portion 110, specifically, on the side wall 100 a side.

  The circumferential dimension W1 of the inclined groove portion 161 is not less than 1.32 times and not more than 2.17 times the circumferential dimension W2 of the inclined groove portion 162. W1 is preferably 1.64 times to 1.96 times W2.

  The ratio of the area of the widthwise inclined groove 160 to the area of the V-shaped land portion block 101 is 10% or more and 40% or less. In addition, it is preferable that the said ratio is 12%-32%. Further, the ratio of the area of the V-shaped land portion block 101 to the contact area of the pneumatic tire 10 is 10% or more and 31% or less. The ratio is preferably 9% to 12%.

  The ratio of the widthwise dimension of the inclined groove portion 161 to the width (between the side wall 100a and the side wall 100b) in the tire width direction of the V-shaped land portion block 101 is 50% or more and 78% or less. The ratio is preferably 52% to 68%.

  The circumferential dimension of the inclined groove portion 161 is preferably, for example, about 2.7 to 6.1 mm, and the circumferential dimension of the inclined groove portion 162 is preferably, for example, about 1.4 to 3.9 mm.

(2.2) Central land section row 200
FIG. 6 is a partially enlarged plan view of the central land portion row 200. As shown in FIG. The central land portion row 200 is a composite land portion row including the land portion row 201 (first land portion row) and the land portion row 202 (second land portion row) provided along the tire circumferential direction. The land portion row 201 and the land portion row 202 are adjacent in the tire width direction.

  In the present embodiment, the land portion row 201 is provided closer to the tire equator line CL than the land portion row 202. In addition, at least a part of the central land portion row 200 is provided in the center region including the tire equator line CL. The definition of the center area is as described above.

  The land portion row 201 is configured by a plurality of land portion blocks 210 (first land portion blocks) formed along the tire circumferential direction. Moreover, the land part row | line | column 202 is comprised by several land part block 260 (2nd land part block) formed along a tire circumferential direction.

The land portion block 210 is formed with an end slope groove 220 (first end slope groove) which is inclined with respect to the tire width direction and opens in the side wall 210 a on the land portion row 202 side. Further, in the land portion block 210, a wedge-shaped notch groove 240 is formed which is open to the side wall 210b opposite to the land portion row 202 side.
The notch groove 240 is not limited to the wedge shape, and may have a shape that tapers toward the tip of the notch groove 240.

  One end of the end slope groove 220, specifically, the end 221 ends in the land block 210. Further, the tip end 241 of the notch groove 240 also terminates in the land block 210.

  Between adjacent land blocks 260, cross slope grooves are formed to separate the adjacent land blocks 260. Specifically, the transverse inclined grooves 270 are formed between the adjacent land blocks 260.

  The transverse inclined groove 270 inclines in the same direction as the terminal inclined groove 220. That is, in the tread surface view, the extending direction of the transverse inclined groove 270 and the extending direction of the terminal inclined groove 220 are the same direction.

  The land block 210 is formed with a plurality of sipes 230 which extend in a direction different from the extending direction of the transverse inclined grooves 270 and which is inclined with respect to the tire width direction. Also, in the land block 260, a plurality of sipes 290 which are different from the extending direction of the transverse inclined grooves 270 and extend in a slanting direction with respect to the tire width direction are formed. In the present embodiment, the sipe 230 and the sipe 290 have a zigzag shape in the tread surface view.

  The end slope groove 220 and the notch groove 240 are located on the extension along the cross slope groove 270.

  The land block 260 is inclined in the same direction as the end slope groove 220, and is opened on the side wall opposite to the first land portion row side (an end slope groove 280 (second end slope groove) is formed. End) One end of the inclined groove 280, specifically, the end 281 ends in the land block 260.

  The sipe 230 includes a communicating sipe 231 in communication with the end inclined groove 220. One end of the communication sipe 231 communicates with the end portion (end 221) of the end inclined groove 220. On the other hand, the other end of the communication sipe 231 opens in the side wall 210b opposite to the land portion row 202 side.

  The end inclined groove 220 and the cross inclined groove 270 are inclined in the opposite direction to the sipes 230 and the sipes 290 with respect to the tire width direction.

  The transverse inclined groove 270 has a first groove width 271 (first groove) having the same circumferential dimension (groove width) as the terminal inclined groove 220 and a circumferential dimension (groove width) more than the first groove width 271 And a second groove width portion 272 (second groove portion). The first groove width portion 271 is formed on the land portion block 210 side.

  Further, a ridged groove portion is formed at an end portion of the transverse inclined groove 270 on the side opposite to the land portion row 201 side. Specifically, a ridged groove 273 is formed at the end of the transverse inclined groove 270. The ridged groove portion 273 is inclined in the same direction as the sipe 290 and is inclined in the opposite direction with respect to the end inclined groove 280 with respect to the tire width direction. The wedge-shaped groove portion 273 communicates with the second groove width portion 272.

  Further, between the land portion row 201 and the land portion row 202, a circumferential groove 60 (row inner circumferential groove) extending in the tire circumferential direction is formed. The circumferential groove 60 does not extend linearly in the tire circumferential direction. The circumferential groove 60 has a circumferential groove and an inclined lug groove.

  Specifically, the circumferential groove 60 communicates with the circumferential groove 61 extending in the tire circumferential direction and inclined with respect to the tire circumferential direction, and the circumferential groove 61 adjacent in the tire circumferential direction, and extends in the tire width direction And an inclined lug groove 62 inclined in the same direction as the end inclined groove 220 with respect to the tire width direction.

  Side walls located at the tire circumferential end of the land block 210, specifically, (the side walls 210c and 210d are inclined with respect to the tire width direction. Similarly, the tire circumferential end of the land block 260 The side walls located in the portion, specifically, the side walls 220c and 220d are also inclined with respect to the tire width direction.

  Also, these side walls are inclined in the opposite direction to the sipes 230 and the sipes 290 with respect to the tire width direction, that is, based on the tire width direction. Furthermore, the inclination angles of the sipe 230 and the sipe 290 with respect to the tire width direction are larger than the inclination angles of the side walls (side walls 210c, 210d, 220c, 220d) with respect to the tire width direction.

  Specifically, the inclination angles of the sipe 230 and the sipe 290 are 9 degrees or more and 39 degrees or less. The inclination angle is preferably 12 degrees to 24 degrees. Further, the inclination angle of the side wall (side wall 210c, 210d, 220c, 220d) is 6 degrees or more and 36 degrees or less. The inclination angle is preferably 11 degrees to 31 degrees.

  The extending direction of the transverse inclined groove 270 is inclined in a direction different from that of the sipes 230 and the sipes 290 with respect to the tire width direction. Specifically, in the tread surface view, the extension direction of the extension along the transverse inclined groove 270 inclines upward to the right. On the other hand, the extending direction of the sipe 230 and the sipe 290 inclines to the left.

  The total area of the end slope groove 220, the end slope groove 280 and the cross slope groove 270 in the contact surface with the road surface of the pneumatic tire 10 is the groove total area S1, and one end in the tire width direction of the central land portion row 200 S1 / S2 is 0.05 or more and 0.25 or less, when the total area of the land part and the groove part to the other end in the tire width direction of central land part line 200 is set as composite land part line total area S2 from . In addition, it is preferable that S1 / S2 is 0.05-0.15.

  Moreover, the space | interval in the circumferential direction of the adjacent sipe 230 in the land part block 210 is 3.3 mm or more and 10.0 mm or less. In addition, it is preferable that the said sipe space | interval is 3.7 mm-5.6 mm. Moreover, the space | interval in the circumferential direction of the adjacent sipe 290 in the land part block 260 is 4.4 mm or more and 10.0 mm or less. In addition, it is preferable that the said sipe space | interval is 5.5 mm-8.3 mm.

  The spacing in the circumferential direction of the sipe 230 is the “sipe spacing” shown in FIG. 11 and is the spacing (distance) between adjacent sipes 230 that intersects a straight line parallel to the tire circumferential direction.

  The negative rate of the land block 210 is 8.9% or more and 20.7% or less. The negative ratio is preferably 11.8% to 17.8%. Also, the negative rate of the land block 260 is 11.8% or more and 27.4% or less. The negative ratio is preferably 15.7% to 23.5%.

  Furthermore, the average negative ratio of the land block 210 and the land block 260 adjacent to the land block 210 is 13.2% or more and 30.8% or less. The negative ratio is preferably 17.6% to 26.4%.

  The negative ratio of the land portion block 210 is the total area of the land portion of the land portion block 210 (not including the closing sipes in the ground) and the end slope groove 220 and the notch groove 240 formed in the land portion block 210 The ratio (percentage) of the total area of the end slope groove 220 and the notch groove 240 is Also, the negative ratio of the land block 260 is the end slope with respect to the total area of the land (not including the closing sipes in the ground) of the land block 260 and the end slope groove 280 formed in the land block 260. It is the ratio of the area of the groove 280.

  In the present embodiment, the inclination angle of the sipe 290 with respect to the tire width direction, the inclination angle of the end inclined groove 220 with respect to the tire width direction, the second end inclined groove and the cross inclined groove 270 are the sipes 230 with respect to the tire width direction in the land block 210. And the inclination angle of the end inclined groove 220.

  Further, the end slope groove 220, the second end slope groove, and the cross slope groove 270 are inclined in the direction opposite to the sipes 230 and the sipes 290 with respect to the tire width direction.

  FIGS. 7A and 7B are explanatory views of the rotational moment generated in the land portion block 210 and the rotational moment generated in the conventional land portion block 210P.

  As shown in FIGS. 7A and 7B, the force in the vector direction along the side wall of the tire circumferential direction end does not try to rotate the land portion block 210 and the land portion block 210P. The input in the vector direction perpendicular to the side wall of the frame generates a moment for rotating the land block (in the left rotation direction in FIGS. 7A and 7B).

  In the land block 210, the rotational moment generated at the sidewall position of the tire circumferential end of the land block 210 and the position at which the sipe 230 is formed rotate in opposite directions with respect to the input in the tire circumferential direction. Because the rotational moments cancel each other out, the deformation of the land block 210 is suppressed.

(2.3) Shoulder land portion row 300 in and shoulder land portion row 300 out
FIG. 8 is a partially enlarged plan view of the shoulder land portion row 300in. FIG. 9 is an enlarged perspective view of the land block 310 constituting the shoulder land row 300in.

  The shoulder land portion row 300in and the shoulder land portion row 300out have symmetrical shapes based on the tire equator line CL. Here, the shape of the shoulder land portion row 300 in will be described.

  The land portion block 310 constituting the shoulder land portion row 300 in is a land portion block divided by the circumferential groove 50 and the lug groove 70. In the present embodiment, the land block 310 is provided at the tread end including the ground contact end with the road surface in the tire width direction.

  The land block 310 includes a zigzag circumferential sipe 320 extending in the tire circumferential direction, a zig-zag widthwise sipe 330 (equatorial widthwise sipe) extending in the tire width direction, and a widthwise sipe 340 (tread end width Direction sipes) are formed.

  The widthwise sipe 330 is located closer to the tire equator line CL than the circumferential sipe 320. The widthwise sipe 340 is positioned closer to the tread end side in the tire width direction than the circumferential sipe 320.

  The zig-zag circumferential sipe extending in the tire circumferential direction means a sipe which is bent in a zig-zag shape in the extending direction of the tread surface, which is the tire circumferential direction. The zigzag widthwise sipe extending in the tire width direction refers to a sipe which is bent in a zigzag shape in the extending direction of the tread surface, which is the tire width direction.

  In the land portion block 310, a circumferential direction edge component as an edge component in the tire circumferential direction by a sum L1 of width direction edge components as an edge component in the tire width direction by the circumferential direction sipe 320, a width direction sipe 330, and a width direction sipe 340 The ratio L1 / L2 to the total L2 of is 16.0% or more and 37.4% or less. Note that L1 / L2 is preferably 21.4% to 32.0%.

  In addition, when the pneumatic tire 10 scratchs the road surface with a groove or a sipe, the edge component exerts an edge effect that acts in a direction perpendicular to the input direction from the road surface to the pneumatic tire 10, such as a groove or sipe. The dimension (length) in which the sipe extends in the direction perpendicular to the input direction from the road surface.

  The edge component of one widthwise sipe in the land block, even if the widthwise sipe extends linearly on the tread surface or has an amplitude such as a zigzag waveform, the sipe is relative to the tire equator line CL It is a dimension projected on a straight line inclined at 90 degrees, that is, on a straight line parallel to the tire width direction.

  Further, as described above, unless otherwise specified, the edge component refers to a so-called circumferential edge component along the tire width direction of the land block where a force acts in the tire circumferential direction, as an edge component. The edge components include block edge components by block edges and sipe edge components by sipe edges.

  Further, the ratio (L1 + L2) / L3 of the sum of the total L1 and the total L2 to the average dimension L3 in the tire circumferential direction of the land block 310 is 3.4 or more and 7.8 or less. In addition, it is preferable that the said ratio is 3.9-5.9. When there are a plurality of variations in circumferential dimension of the land portion block 310 formed in a plurality along the tire circumferential direction, that is, when the shoulder land portion row 300in has a plurality of pitches, the average dimension L3 The mean value of the circumferential dimension of the land block 310 is meant.

  In the present embodiment, the zigzag repetition period T of the circumferential sipe 320 is equal to the interval h of the widthwise sipes 340 adjacent to each other in the tire circumferential direction. The period T may be smaller than the interval h.

  Further, the width direction amplitude (amplitude A1) which is the amplitude in the tire width direction of the circumferential sipe 320 is larger than the circumferential direction amplitude (amplitude A2, A3) which is the amplitude in the tire circumferential direction of the width direction sipe 340.

  The land portion block 310 is formed with a circumferential sub-sipe extending in the tire circumferential direction. Specifically, in the land block 310, linear circumferential straight sipe 351 and circumferential straight sipe 352 are formed. The circumferential sub-sipe does not have to be linear as in the circumferential linear sipe 351 and the circumferential linear sipe 352, and may have one bent portion or the like with a shallow angle.

  One end of the circumferential straight sipe 351 and one end of the circumferential straight sipe 352 communicate with the widthwise sipe 340. On the other hand, the other ends of the circumferential straight sipe 351 and the circumferential straight sipe 352 are opened in the side walls 310 a and 310 b located on the tire circumferential end side of the land portion block 310.

  The circumferential sipe 320 includes a linear portion linearly extending in parallel to the tire circumferential direction. Specifically, circumferential sipe 320 includes straight portion 321 and straight portion 322).

  The straight portion 321 and the straight portion 322 are formed at the end of the land portion block 310 in the tire circumferential direction. Specifically, the linear portion 321 is formed on the side wall 310 a side of the tire circumferential direction end of the land portion block 310, and the linear portion 322 is formed on the side wall 310 b side.

  The linear portion 321 and the linear portion 322 are formed at a position offset from the central position CT of the amplitude A1 in the tire width direction of the circumferential sipe 320. That is, the linear portions 321 and the linear portions 322 are formed at positions deviated from the central position CT in the tire width direction.

  The end portion 332 on the tread end side of the widthwise sipe 330 communicates with the circumferential sipe 320. On the other hand, the end 341 on the tire equator line CL side of the widthwise sipe 340 does not communicate with the circumferential sipe 320 and terminates in the land block 310 on the tread end side of the circumferential sipe 320.

  Further, the end 331 of the widthwise sipe 330 on the tire equator line CL side communicates with the circumferential groove adjacent to the land block 310, specifically, the circumferential groove 50 formed on the tire equator line CL side. Do. On the other hand, the end 341 on the tread end side of the widthwise sipe 340 terminates in the land block 310.

  Further, the end portion 332 on the tread end side of the widthwise sipe 330 communicates with the top portion 323 of the zigzag circumferential sipe 320. The widthwise sipe 340 is located on the extension of the widthwise sipe 330 in communication with the top portion 323 of the zigzag circumferential sipe 320.

  The circumferential sipe 320 has a predetermined amplitude (amplitude A1) in the tire width direction. The end 341 of the widthwise sipe 340 is located within the amplitude A1.

  The side wall 310 b located on the tire circumferential direction end side of the land portion block 310 is formed with a notch-like step portion like a notch of the land portion block 310. Specifically, the step portion 360 is formed at the end of the land portion block 310 in the tire width direction on the tread end side.

  The stepped portion 360 is formed only on one side wall on the tire circumferential direction end side of the land portion block 310, specifically, only on the side wall 310b.

  As shown in FIG. 9, the stepped portion 360 has a raised bottom surface located on the outer side in the tire radial direction than the groove bottom 70 b of the lug groove 70. Specifically, the step portion 360 has a rectangular raised bottom surface 361 extending in the tire width direction.

  In the present embodiment, the raised bottom surface 361 is inclined with respect to the tire radial direction in the tire side view. The position of the raised bottom surface 361 in the tire radial direction is not particularly limited, but from the viewpoint of securing the block rigidity of the land portion block 310, 25% to 50% of the height (length in the tire radial direction) of the land portion block 310 It is preferable to

  One end of the circumferential linear sipe 352, specifically, the end 352a on the side wall 310b side is opened in the side wall 310b of the tire circumferential direction end on the step portion 360 side of the land block 310. That is, the end 352 a opens at the end 362 on the tire equator line CL side of the step portion 360. On the other hand, the other end of the circumferential linear sipe 352, specifically, the end 352 b on the widthwise sipe 340 side communicates with the widthwise sipe 340.

  The raised bottom surface 361 is inclined so that the height in the tire radial direction becomes lower toward the tire circumferential direction end of the land block 310, that is, the side wall 310b.

  A zigzag surface having a predetermined amplitude in the tire circumferential direction is formed on the side wall on the tire circumferential direction end side of the land portion block 310. Specifically, zigzag surfaces 380 are respectively formed on the side walls 310a and 310b. The zigzag surface 380 is formed at the end of the side wall 310 a and the side wall 310 b on the tire equator line CL side. The shape of the zigzag surface 380 is the same as that of the widthwise sipe 340 in the tread surface view.

(3) Relationship between Pitch and Sipe of Land Block in Pneumatic Tire 10 Next, the relationship between the pitch and sipe in the pneumatic tire 10 will be further described with reference to FIGS.

  FIG. 10 is a diagram showing the definition of various dimensions of the V-shaped land portion row 100. As shown in FIG. FIG. 11 is a diagram showing the definition of various dimensions of the central land portion row 200. As shown in FIG. FIG. 12 is a diagram showing the definition of various dimensions of the shoulder land portion row 300 in. FIG. 13 is a partial plan development view of a pneumatic tire 10A in which a pitch different from that of the pneumatic tire 10 shown in FIGS. 1 to 12 is set.

  As described above, in the pneumatic tire 10 (and the pneumatic tire 10A, hereinafter the same), one or more sipes extending in the tire width direction in at least a part of the land blocks of the plurality of land blocks Is formed.

  Assuming that the average sipe interval, which is the average interval between adjacent sipes in the tire circumferential direction, is h, and the average pitch length, which is the average dimension of repeating units of land blocks in the tire circumferential direction, is L, the following relationship is satisfied preferable.

0.130 ≦ (h / L) ≦ 0.400
In addition, the range of 0.137-0.197 is more preferable, and the range of 0.144-0.19 is more preferable for (h / L).

  Here, the average sipe interval h (unit mm) is the average circumferential dimension of the sipe in the land block and the sipe adjacent in the tire circumferential direction. However, when there is no sipe adjacent to the sipe in the tire circumferential direction, the circumferential dimension of the tire circumferential direction end of the land block and the sipe is used.

  When no sipes are formed (in the case of 0), the circumferential dimensions of one tire circumferential end of the land block and the other tire circumferential end are obtained. Usually, the land block is divided by sipes substantially equally in the tire circumferential direction, but may not be equal. Here, unless otherwise noted, the average sipe interval h is the average value of all land blocks provided on the land block row.

  Moreover, a pitch is one basic unit of the tread pattern comprised by the pattern continuously repeated in the tire peripheral direction by length of 1 type or several types. The average pitch length L (unit mm) refers to the distance of the pitch in the tire circumferential direction. Unless otherwise noted, the average pitch length L refers to the circumferential dimension of the average pitch in the land block row.

  Further, it is preferable that the average sipe interval h and the average pitch length L satisfy the following relationship.

140 (mm) ² ≦ (h * L) ≦ 350 (mm) ² (Hereinafter, unit (mm) ² is omitted)
The range of 148 to 250 is more preferable, and the range of 150 to 220 is more preferable.

  The average sipe distance h of the center part land block preferably satisfies the relationship 3.0 mm ≦ h ≦ 7.1 mm. In addition, it is more preferable to satisfy the relation of 3.5 mm ≦ h ≦ 6.6 mm, and more preferable to satisfy the relation of 3.7 mm ≦ h ≦ 5.6 mm.

  The average sipe distance h of the second land block preferably satisfies the relationship of 3.3 mm ≦ h ≦ 7.7 mm. The average sipe distance h of the second part land block is more preferably satisfying the relation of 3.8 mm ≦ h ≦ 7.2 mm, and still more preferably satisfying the relation of 4.1 mm ≦ h ≦ 6.1 mm.

  In addition, it is preferable that the average sipe distance h of the shoulder land block satisfies the relationship of 3.7 mm ≦ h ≦ 8.5 mm. The average sipe distance h of the shoulder land block is more preferably satisfying the relation of 4.2 mm ≦ h ≦ 8.0 mm, and still more preferably satisfying the relation of 4.5 mm ≦ h ≦ 6.8 mm.

  In addition, the definition of a center part, a 2nd part, and a shoulder part is as having mentioned above.

  A plurality of sipes extending in the tire width direction are formed in the land block of the pneumatic tire 10 according to the present embodiment. In this case, the average sipe distance h preferably satisfies the relationship of 3.4 mm ≦ h ≦ 7.9 mm. In this case, the average sipe interval h more preferably satisfies the relationship of 3.9 mm ≦ h ≦ 7.4 mm, and further preferably satisfies the relationship of 4.2 mm ≦ h ≦ 6.3 mm.

  In this case, it is preferable that the average pitch length L satisfy the relationship of 19.2 mm ≦ L ≦ 44.6 mm. The average pitch length L more preferably satisfies the relationship of 22.0 mm ≦ L ≦ 41.6 mm, and more preferably satisfies the relationship of 23.6 mm ≦ L ≦ 35.4 mm.

  Also, let Dball be an average block edge component that is an average of edge components of all land blocks in the tire circumferential direction, and Dsall be an average sipe edge component that is an average of edge components of all sipes in the tire circumferential direction. Assuming that an average block stiffness which is an average of stiffness values of partial blocks is G, it is preferable to satisfy the following relationship.

^{2.20 (mm) 3 /N≦(Dball/Dsall)/G≦4.00(mm) 3} / N ( hereinafter, the unit (mm) ³ / N is omitted)
The definition of the edge component is as described above. Further, the block stiffness which is the source of the average block stiffness G is a value when shear deformation is applied in the tire circumferential direction. Specifically, the block stiffness per unit area is calculated by the following equation.

Shear stress (N / mm) / Land block ground area (mm ² )
In practice, the measurement using an Amsler tester as described in Japanese Patent No. 4615983 is calculated by FEM.

Assuming that (Dballc / Dsallc) / Gc for the central part land block is Rc and (Dball ₂ / Dsall ₂ ) / G ₂ for the second part land block is R ₂ , the following relationship is given It is preferable to satisfy.

2.20 ≦ (Dball / Dsall) /G≦4.00
1.10 ≦ (R ₂ /Rc)≦5.88
It is more preferable to satisfy 2.40 ≦ (R ₂ /Rc)≦3.55, and it is more preferable to satisfy 2.50 ≦ (R ₂ /Rc)≦3.50.

Also, assuming that (Dball ₂ / Dsall ₂ ) / G ₂ for the second land block is R ₂ and (Dballs / Dsalls) / Gs for the shoulder land block is Rs, It is preferable to satisfy the relationship.

1.10 ≦ (Rs / R ₂ ) ≦ 2.90
It is more preferable to satisfy 1.10 ≦ (Rs / R ₂ ) ≦ 2.35, and it is further preferable to satisfy 1.20 ≦ (Rs / R ₂ ) ≦ 1.80.

  Furthermore, assuming that an average block edge component that is an average of edge components of all land blocks in the tire circumferential direction is Dball, and an average sipe edge component that is an average of edge components of all sipes in the tire circumferential direction is Dsall, It is preferable to satisfy the following relationship.

0.15 ≦ (Dball / Dsall) ≦ 0.48
It is more preferable to satisfy 0.21 ≦ (Dball / Dsall) ≦ 0.31, and it is further preferable to satisfy 0.23 ≦ (Dball / Dsall) ≦ 0.29.

Also, assuming that (Dballc / Dsallc) for the central part land block is Pc and (Dball ₂ / Dsall ₂ ) for the second part land block is P ₂ , the following relationship is satisfied: preferable.

1.12 ≦ (P ₂ /Pc)≦5.88
It is more preferable to satisfy 1.15 ≦ (P ₂ /Pc)≦4.00, and it is further preferable to satisfy 1.17 ≦ (P ₂ /Pc)≦2.50.

Furthermore, (Dballc / Dsallc) for the central part land block is Pc, (Dball ₂ / Dsall ₂ ) for the second land block is P ₂ , and the shoulder land block is target When (Dballs / Dsalls) is Ps, it is preferable to satisfy the following relationship.

0.81 ≦ {(Ps / P ₂ ) / (P ₂ /Pc)}≦3.70
It is more preferable to satisfy 0.94 ≦ {(Ps / P ₂ ) / (P ₂ /Pc)}≦3.00, and satisfy 0.96 ≦ {(Ps / P ₂ ) / (P ₂ /Pc)}≦2.80 It is further preferable to do.

Further, the center portion land portion blocks, an average sipe interval is the average interval between sipes adjacent in the tire circumferential direction and hc, if the average sipe interval in the second portion land portion blocks and h _2, to satisfy the following relation Is preferred.

1.00 ≦ (h ₂ /hc)≦7.00
It is more preferable to satisfy 1.12 ≦ (h ₂ /hc)≦4.00, and it is more preferable to satisfy 1.12 ≦ (h ₂ /hc)≦2.00.

  Furthermore, when the average sipe interval in the shoulder land block is hs, the following relationship is preferably satisfied.

1.05 ≦ (hs / hc) ≦ 4.00
It is more preferable to satisfy 1.05 ≦ (hs / hc) ≦ 3.00, and it is further preferable to satisfy 1.82 ≦ (hs / hc) ≦ 2.33.

  Furthermore, it is preferable to satisfy the following relationship.

0.97 <≦ (hs / h ₂ ) ≦ 2.15
It is more preferable to satisfy 0.97 ≦ (hs / h ₂ ) ≦ 1.71 and it is further preferable to satisfy 0.98 ≦ (hs / h ₂ ) ≦ 1.27.

(4) Operation / Effect Next, the operation / effect of the above-described pneumatic tire 10 will be described. Specifically, the actions and effects of the pneumatic tire 10 as a whole, and the actions and effects of the V-shaped land portion row 100, the center land portion row 200, the shoulder land portion row 300in, and the shoulder land portion row 300out will be described.

(4.1) V-shaped land section row 100
The V-shaped land portion block 101 has a convex portion 110 on one side wall in the tire circumferential direction, and a recessed portion 120 on the other side wall, and the side wall of both sides has the same inclination angle. The sipe 130, 140 or the end slope groove 150 is at the same slope angle as the side wall. For this reason, the rigidity of the central portion becomes higher than that of the rectangular land portion block without the bent portion by having the bent portion in the most convex portion 110a (central portion) where the apex of the convex portion 110 is located, and the V shape The rigidity of the entire land block 101 is increased. As a result, the falling of the V-shaped land portion block 101 and the lifting from the road surface are suppressed, and the ground contact area is improved.

  Further, since both ends in the tire width direction of the V-shaped land block 101 have lower block rigidity than the central portion, they are greatly deformed in the tire circumferential direction with respect to the tire circumferential direction input at the time of braking to improve edge effect Let

  Conventionally, since the rigidity of the V-shaped land block improves in the central portion, the ground area can be secured in the central portion by increasing the width direction dimension with respect to the circumferential dimension of the V-shaped land block. The dimension in the width direction of the part was increased to lengthen the edge in the circumferential direction of the tire. Also, by reducing the circumferential dimension of the V-shaped land block and inserting as many V-shaped land blocks as possible into the tread, the V-shaped land block is appropriately deformed to such an extent that the ground contact area can be secured. While improving the edge effect due to the block edge and the sipe edge.

  In the present embodiment, the circumferential dimension of the V-shaped land block 101 is larger than the width dimension of the V-shaped land block 101. For this reason, the block stiffness in the tire circumferential direction of the V-shaped land portion block 101 is increased. Since the circumferential dimension of the V-shaped land portion block 101 is increased, the block stiffness in the tire circumferential direction of the central portion in the tire width direction is increased, and the block stiffness in the tire circumferential direction of both end portions in the tire width direction is also enhanced. Furthermore, the central part maintains the height of block rigidity to both ends.

  Further, in the central portion of the V-shaped land portion block 101, the ground contact area is further improved, and the block edge and the sipe edge are strongly pressed against the road surface by the increase of the block rigidity, and the edge effect is also improved. Large deformation is also suppressed at both ends of the V-shaped land block 101, and the ground contact area is improved. Therefore, instead of the edge effect due to the deformation, the edge effect strongly pressed against the road surface due to the increase in block rigidity is improved. Furthermore, the wear resistance performance is improved by increasing the block rigidity.

  As a result, the V-shaped land portion block 101 falls during braking of the vehicle equipped with the pneumatic tire 10, and in particular, falls in the circumferential direction of the tire can be suppressed, and wear of the V-shaped land portion block 101 can be effectively suppressed. . The circumferential dimension of the V-shaped land portion block 101 may be the same as the width dimension in consideration of an effect that can be exerted. This is because it is effective to increase the widthwise dimension with respect to the circumferential dimension of the land block as in the prior art.

  Further, since the rigidity in the circumferential direction of the tire of the V-shaped land portion block 101 is high at both the central portion and both end portions, the contact area of the V-shaped land portion block 101 at the time of braking is significantly improved.

  In the V-shaped land portion block 101, the inclination angle θ1 of the convex sidewall portion 111 (112) with respect to the tire width direction is the same as the inclination angle θ2 of the concave sidewall portion 121 (122) with respect to the tire width direction. Further, the inclination angle θ5 of the sipe 130 and the terminal end inclined groove 150 with respect to the tire width direction is the same as the inclination angle θ1 (inclination angle θ2) of the convex side wall portion 111 (recessed side wall portion 121) with respect to the tire width direction.

  For this reason, the moment generated in the convex sidewall portion 111 (112) of the V-shaped land block 101 and the sipe 130 (140) tends to rotate in the same direction, so the edge effect of the block edge and the sipe edge is the same direction To be Thereby, the ability to scratch the road surface by the block edge component by the shape of the V-shaped land block 101 and the sipe edge component by the sipe 130 can be improved.

  Further, the end 131 of the sipe 130 and the end 151 of the end inclined groove 150 end in the V-shaped land portion block 101. Furthermore, on the extension of the communication sipe 141, the side wall 100c of the V-shaped land portion block 101 that constitutes the end 151 of the end inclined groove 150 is continuous.

  Therefore, the circumferential dimension of the V-shaped land block 101 can be made larger than the widthwise dimension, as compared with the case where the V-shaped land block 101 is divided by the sipe and the inclined groove from end to end. . As a result, as described above, the block rigidity of the V-shaped land portion block 101 is increased, the ground contact area is increased, and the block edge and the sipe edge are increased due to the block rigidity. As a result, according to the V-shaped land portion row 100, the abrasion resistance performance can be improved while the performance on ice is improved.

In the V-shaped land portion row 100, the inclined groove (end inclined groove 150) is terminated and a part thereof is replaced by the communication sipe 141 in order to prevent the block edge and the sipe edge from being reduced due to the decrease in block rigidity. It is a thing.
Although it is desirable to divide the V-shaped land portion block 101 from end to end by inclined grooves, in the case of division, the circumferential dimension of the land portion block becomes smaller than the width direction dimension, so the block rigidity decreases. The ground contact area is reduced.

  The portion where the sipe communicates as the communication sipe 141 with the end inclined groove 150 is originally the portion where the communication sipe 141 is intended to be divided by the inclined groove to generate a block edge, and the inclined groove The reason is that in order to reduce the edge as much as possible by forming the sipes while not reducing the block stiffness.

  Further, since the V-shaped land portion block 101 is divided by the end slope groove 150 and the communication sipe 141, the block rigidity is lower than that of the portion connected without being divided. When the sipe is separated without communicating the sipe, only the block rigidity of the V-shaped land block 101 in the separated portion becomes high, and the distribution of the block rigidity in the tire width direction of the V-shaped land block 101 becomes smooth. It does not change and a rigid level difference will occur.

  In the V-shaped land portion block 101, the communication between the communicating sipe 141 and the end sloped groove 150 makes the V-shaped land portion block 101 compared with a shape in which the inclined groove crosses the V-shaped land portion block 101. Block rigidity is greatly improved. As a result, the contact area can be improved and the edge effect can be improved, and the performance on ice can be improved while the wear resistance can be improved.

  In the V-shaped land portion row 100, a communication sipe 142 in communication with the notched recess portion 170 is formed, and the width of the notched recess portion 170 in the tire circumferential direction extends toward the side wall 100b of the V-shaped land portion block 101. For this reason, the block edge component of the V-shaped land portion block 101 is increased by the notch recess 170.

  Further, in the present embodiment, by forming the notched recess 170 which is a wedge-shaped (triangular) wedge-shaped groove, the vicinity of the open end of the communication sipe 142 is compared with the case where the communication sipe 142 is opened to the side wall 100 b. The block rigidity of the portion where the block rigidity is originally low where the angle between the sipe opening end of the V-shaped land block 101 and the side wall of the V-shaped land block 101 is an acute angle is high.

  For this reason, the force which presses communicating sipe 142 on a road surface becomes large, and the edge effect of a sipe edge improves. In addition, the increase in block rigidity in this way can prevent the sipe-formed portion from floating up from the road surface so as to be turned up at the time of braking, thereby preventing the reduction in the wear resistance performance.

  In general, winter tires have a long contact length near the tire equator line and a short contact length on the outer side in the tire width direction, so in the land block, sipes edge or block in the tire circumferential direction near the tire equatorial line near the tire equatorial line. While improving the edge effect by positively increasing the edge, block rigidity is secured at the outer portion in the tire width direction.

  Therefore, in order to increase the block edge, the side wall at the tire circumferential direction end of the V-shaped land block is elongated near the tire equator and is shortened outside the tire width direction. However, if the same configuration is used up to the sipes, the block rigidity on the tire equatorial line side of the V-shaped land block excessively decreases, and the rigidity balance in the tire width direction of the V-shaped land block deteriorates.

  That is, although the short sipe 130 is formed on the long convex portion side wall portion 111 side and the long sipe 140 is formed on the short convex portion side wall portion 112, the tire of the V-shaped land portion row 100 is reversed. The rigidity balance in the width direction is largely broken.

  In the V-shaped land portion block 101, by setting the short sipe 130 in the vicinity of the tire equator and the long sipe 140 in the tire width direction, the block rigidity in the tire width direction is balanced. Is secured.

  Further, by lengthening the sipe 140 on the outer side in the tire width direction, not only the block rigidity by the bent portion (the convex portion 110 and the concave portion 120) is increased but also the sipe edge is increased. Furthermore, since the block rigidity on the outer side in the tire width direction is increased, the force pressing the V-shaped land portion block 101 including the sipe 140 against the road surface is increased, and the sipe edge is increased. Moreover, not only the block rigidity of the central part is high as in the conventional V-shaped land block but also the central part having a bent part and the block on the tire equator line CL side of the V-shaped land part block 101 and the tire width direction outer side Since the rigidity is improved, the wear resistance performance of the V-shaped land block 101 is also improved.

  In the V-shaped land portion block 101, the circumferential dimension W1 of the inclined groove portion 161 located on one side (tire equatorial line side) in the tire width direction relative to the bent portion 163 is the other side in the tire width direction than the bent portion 163 ( It is wider than the circumferential dimension W2 of the inclined groove portion 162 located on the tread end side).

  Therefore, in the V-shaped land portion block 101, the tire width between the V-shaped land portion blocks 101 adjacent in the circumferential direction is set so that the land portion block does not fall down on the tread end side, that is, the block rigidity is increased. The circumferential dimension of the land portion block is enlarged only on one side in the direction, and the circumferential dimension of the inclined groove portion 162 is smaller than that of the inclined groove portion 161. Therefore, the most convex portion 110a and the most concave portion 120a are at different positions.

(4.2) Central land section row 200
When the circumferential side walls of the inclined land block which inclines with respect to the tire width direction such as the land block 210 and the land block 260 formed in the central land row 200 receive an input in the tire circumferential direction, As shown in FIGS. 7A and 7B, the force in the vector direction along the side wall at the end of the tire circumferential direction does not try to rotate the land block 210 (and the land block 210P). The input to the land block 210 along the vector direction perpendicular to the side wall of the circumferential end generates a moment for rotating the land block 210 (in FIG. 7 (a) and (b), left rotation) direction).

  Since the rotational moment generated in the transverse inclined groove 270 and the terminal inclined groove 220 tends to rotate in the same direction, the edge effect of the land block by the groove wall portion of the transverse inclined groove 270 and the terminal inclined groove 220 is the same direction To be For this reason, the block edge component as the center land part row 200 whole increases.

  As shown in FIG. 7A, since rotational moment generated in the land portion block 210 and the sipe 230 tends to rotate in opposite directions with respect to the input of the land portion block 210 in the tire circumferential direction, The deformation of the land block 210 is suppressed by the mutual cancellation of the rotational moments.

  Therefore, as compared with the case where the sipes 230 (and the sipes 290) extend in the same direction as the transverse inclined grooves 270, the block rigidity as the central land portion row 200 is significantly improved. Thus, the ground contact area is improved by increasing the block rigidity of the central land portion row 200 as a whole, and the force to press the land portion block 210 (and the land portion block 260) and the sipe 230 (and the sipe 290) against the road surface. Increases. Thereby, the abrasion resistance performance can be improved while the performance on ice is improved by the increase of the edge effect.

  In addition, the end slope groove 220 and the notch groove 240 are located on the extension along the cross slope groove 270. Further, a ridged groove 273 is formed at the end of the transverse inclined groove 270. Therefore, the block edge component is increased by acting like one lug groove crossing the central land portion row 200 while securing the block rigidity.

  The circumferential groove 60 extends in the tire circumferential direction and is inclined with respect to the tire circumferential direction, and an inclined lug groove 62 inclined with respect to the tire width direction in the same direction as the terminal inclined groove 220. Have. The block edge component is further increased by the circumferential groove 60 which does not extend linearly in the tire circumferential direction.

  In the central land portion row 200, the side walls 210c, 210d, 220c, and 220d located at the end portions of the land portion block 210 and the land portion block 260 in the tire circumferential direction are inclined with respect to the tire width direction. In addition, these side walls are inclined in the opposite direction to the sipe 230 and the sipe 290 with respect to the tire width direction.

  For this reason, compared with the case where the sipe 230 and the sipe 290 extend in the same direction as these side walls, it is possible to suppress the decrease in block rigidity as the central land portion row 200. This can improve the antiwear performance while securing the performance on ice.

  As mentioned above, ratio S1 / S2 is a negative rate of central land part line 200, and shows the ratio of the ditch area in central land part line 200. As shown in FIG. If the negative ratio is large, the area of the groove portion increases and the edge effect by the block edge component due to the groove improves, but the area of the land block decreases, so the block rigidity decreases and the contact area decreases. Wear resistance performance is reduced.

  On the other hand, if the negative ratio is small, the area of the groove portion decreases and the area of the land block increases, so the block rigidity increases, and the contact area is improved and the wear resistance performance is improved. Edge effects due to block edge components are reduced.

  For this reason, the end slope groove 220, the end slope groove 280, and the cross slope groove 270 optimally improve the block stiffness of the central land portion row 200. Thus, by setting the negative ratio optimally for the central land portion row 200 as a whole, the block rigidity is increased and the ground contact area is improved. Moreover, the force which presses the land part block 210 and the land part block 260, the sipe 230, and the sipe 290 on a road surface increases. Thereby, the abrasion resistance performance can be improved while the performance on ice is improved by the increase of the edge effect.

  As described above, S1 / S2 is preferably 0.05 or more and 0.25 or less, and when S1 / S2 exceeds 0.25, the negative ratio increases, and the area of the land block significantly decreases. The stiffness is too low. As a result, the contact area is significantly reduced and the wear resistance is significantly reduced.

  In addition, if S1 / S2 is less than 0.05, the negative ratio becomes small, the area of the groove portion is greatly reduced, and drainage performance can not be ensured at all. Also, the edge effect of the block edge due to the groove is greatly reduced.

(4.3) Shoulder land portion row 300in and shoulder land portion row 300out
In the shoulder land portion row 300 in (the same applies to the shoulder land portion row 300 out), the amplitude A1 of the circumferential sipe 320 is larger than the dimension of the amplitude A2 of the width direction sipes 340 adjacent to each other.

  The rigidity of the land portion block 310 is improved and the ground contact area is improved by increasing the sipe distance and decreasing the pitch length of the land portion block 310 constituting the shoulder land portion row 300 in. In addition, the block edge, the force to press the sipe edge against the road surface, and the edge effect by the improvement of the block edge are improved and the wear resistance performance is improved.

  However, if the block rigidity in the tire circumferential direction of the land block 310 does not decrease, the edge effect should be large. Therefore, the amplitude A1 of the zig-zag portion is increased by forming the circumferential sipe 320 that exerts an edge effect in the tire width direction, which hardly reduces the rigidity in the tire circumferential direction, in the land portion block 310. Thereby, the sipe edge in the tire circumferential direction can be exhibited to improve the edge effect in the tire circumferential direction.

  Further, in the land portion block 310, linear circumferential straight sipe 351 and circumferential straight sipe 352 are formed. Such circumferential sipe 320, circumferential linear sipe 351, and circumferential linear sipe 352 can also increase the edge effect in the tire width direction.

  In the shoulder land portion row 300 in, the tire equatorial line CL side of the land portion block 310 is highly rigid and is not restrained from deformation by the inclined side wall of the buttress portion which is the side wall on the tread end outer side like the tread end side. Also, the contact length is longer than the tread end side.

  Therefore, the end 332 of the widthwise sipe 330 on the tire equator line CL side communicates with the circumferential sipe 320 in order to make the sipe edge appear largely. Further, the end 331 of the widthwise sipe 330 also communicates with the circumferential groove 40. Thus, the sipe edge component of the land block 310 can be increased.

  On the other hand, the end 341 on the tire equator line CL side of the widthwise sipe 340 does not communicate with the circumferential sipe 320 and terminates in the land block 310. Unlike the tire equatorial line CL side, the side wall on the tread end outer side of the land block 310 has high rigidity and suppressed deformation by the inclined side wall of the to buttress portion, and the contact length is shorter than the tire equatorial line CL side. The widthwise sipe 340 at the tread end outer side is a circumferential sipe so as to improve the block stiffness instead of reducing the block stiffness in the tire circumferential direction of the land portion block 310 by largely exhibiting a sipe edge on the tire equatorial line CL side. It terminates in land block 310 without communicating with 320. Further, the other end of the widthwise sipe 340 terminates without communicating with either the main groove or the buttress portion.

  For this reason, even if the block rigidity on the tire equator line CL side of the land block 310 is reduced, the block rigidity on the tread end outer side is improved, so that the block rigidity of the shoulder land portion row 300in can be maintained. Further, by maintaining the block rigidity of the shoulder land portion row 300 in, the wear resistance performance can be maintained while the performance on ice is improved by the improvement of the edge effect by the sipe edge component while securing the ground contact area.

  Further, the end 341 of the widthwise sipe 340 is located within the amplitude A1. Furthermore, the widthwise sipe 340 is located on the extension of the widthwise sipe 330 in communication with the top portion 323 of the zigzag circumferential sipe 320. Such a configuration can further enhance the edge effect due to the sipe edge component.

  In the shoulder land portion row 300 in, a notch-like step portion 360 is formed on the side wall 310 b. The stepped portion 360 is formed at an end portion on the tread end side in the tire width direction of the land portion block 310 and has a raised bottom surface 361. The raised bottom surface 361 has a rectangular shape extending in the tire width direction.

  For this reason, by forming the step part 360 which cut the land part block 310, the volume of the lug groove 70 formed between the adjacent land part blocks 310 increases, and what is called snow pillar shear force improves. Do. Furthermore, drainage performance is also improved.

  Further, since the step portion 360 is formed at the end of the land block 310 on the tread end side, it is easy to take in ice and snow, and furthermore, it is easy to discharge the ice and snow solidified as snow columns.

  Further, the stepped portion 360 is formed not at the deep groove bottom but at the end on the tread end side. Specifically, the raised bottom surface 361 facilitates the discharge of ice and snow solidified as snow columns.

  Furthermore, since the side wall at the circumferential direction end of the land block 310 is bent at the position of the step portion 360 by forming the step portion 360, the land portion is formed more than the linear side wall in which the step portion 360 is not formed. The block edge component due to the sidewall 310b of the block 310 also increases.

  Further, the volume of the land block 310 in the upper (tire radial direction outer) portion of the raised bottom surface 361 decreases because the raised bottom surface 361 is provided, but the lower side of the raised bottom surface 361 (tire radial direction inner side) Similarly to the CL side, a land block is formed by the stepped portion 360. Furthermore, since the tread end side of the land block 310 has high rigidity and deformation suppressed by the inclined side walls of the buttress portion, the block stiffness of the land block 310 can be maintained.

  That is, the stepped portion 360 can maintain the wear resistance performance while improving the performance on ice. In addition, the on-snow performance and the drainage performance can be improved.

(4.4) Relationship between pitch and sipe As described above, it is preferable that the average sipe distance h / the average pitch length L be 0.130 ≦ (h / L) ≦ 0.400, and h / L be less than 0.130. Although the pitch length becomes relatively large, the sipe spacing becomes extremely small. As a result, since the number of sipes is very large, the block rigidity of the land block is extremely reduced.

  On the other hand, when h / L exceeds 0.400, the sipe interval becomes relatively large but the pitch length becomes extremely small. As a result, although the number of sipes is very small such as one or two, for example, the pitch length becomes extremely small, and even if the sipe interval is increased, the block rigidity of the land block is not improved. In addition, the sipe edge component is also significantly reduced.

Further, as described above, preferably 140 ≦ (h * L) ≦ 350, and if the product (h * L) of the average sipe interval and the average pitch length is less than 140 (mm) ² , the sipe interval is also The pitch length is too small. As the sipe spacing becomes smaller, the land block is divided into smaller pieces and the block rigidity is reduced. Furthermore, as the pitch length decreases, the block rigidity of the land block decreases. As a result, the block rigidity is too low.

On the other hand, when h * L exceeds 350 (mm) ² , the sipe interval and the pitch length become too large. If the sipe interval is too large, the block rigidity of the land block will be high, but the number of sipe will be too small and the sipe edge effect can not be exhibited. As the pitch length increases, the block stiffness increases, but the number of pitches around the entire circumference of the tire decreases, so the block edge effect is significantly reduced. As a result, the edge effect becomes too small.

  Also, in winter tires such as studless tires, the contact length is higher in the order of the center area (center area land block), the second area (second area land block), and the shoulder area (shoulder land area block). , The longest contact length. For this reason, it is effective to exert sipe edges and block edges in the tire circumferential direction at the time of braking using a long contact length. By making the sipe interval of the center region smaller than that of the second region and the shoulder region, the edge effect in the circumferential direction is largely exhibited.

  As described above, in the center part land part block, it is preferable that 3.0 mm ≦ h ≦ 7.1 mm, and if h is less than 3.0 mm, the land part block is divided so small that the block rigidity becomes too low. It is from. On the other hand, when h exceeds 7.1 mm, the block rigidity is increased, but the number of sipes decreases too much, so that the sipe edge can not be exhibited and the sipe edge effect becomes too small.

  Moreover, it is necessary to increase block rigidity instead of increasing the sipes in the center region as the shoulder region, the second region and the tread edge side are closer. Also, the lateral force input is larger as it is closer to the tread end, and the shoulder region has the largest lateral force. Therefore, in order to increase the block rigidity, the sipe interval is increased.

  Further, as described above, in the shoulder land block, it is preferable that 3.7 mm ≦ h ≦ 8.5 mm, and if h is less than 3.7 mm, the block is divided into small pieces, and the block rigidity becomes too low. It is from. On the other hand, when h exceeds 8.5 mm, although the sublock rigidity becomes high, the sipe edge effect becomes too small. The same applies to the numerical range of the average sipe interval in the second region as in the shoulder region.

  Furthermore, the second region is shorter in contact length than the center region and longer than the shoulder region. Therefore, due to the improvement of the sipe edge effect and the improvement of the block rigidity, the sipe interval is larger than the center region and smaller than the shoulder region. Further, for the same reason as the center area and the shoulder area, it is preferable to set the average sipe interval of the second area within the above-mentioned range.

  Also, as described above, the average sipe spacing h of the land blocks of the whole pneumatic tire 10 is 3.4 mm or more and 7.9 mm, thereby increasing the sipe spacing and reducing the number of sipe blocks. The rigidity is increased, and one sipe edge and one block edge for one land block are increased to the maximum area that can be improved.

  If h is less than 3.4 mm, the land block is divided so small that the block rigidity becomes too small. On the other hand, when h exceeds 7.9 mm, although the block rigidity is high, the sipe edge effect is too small.

  Further, as described above, the average pitch length L of the land block of the entire pneumatic tire 10 is preferably 19.2 mm ≦ L ≦ 44.6 mm, and if the pitch length is less than 19.2 mm, the pitch length becomes smaller. If the block length is too low, and the pitch length exceeds 44.6 mm, the pitch length becomes too large and the block stiffness becomes high, but the number of pitches per tire circumference decreases. For this reason, the block edge effect is significantly reduced, and the block edge effect is too small.

  More specifically, when the average sipe distance is smaller than 3.4 mm or the average pitch length is larger than 44.6 mm, the sipe distance becomes too small and the block is divided into small pieces, thereby reducing the block rigidity. Pass. Also, if the pitch length becomes too large, the number of pitches decreases, so the block edge effect becomes too small. Also, no matter how large the pitch length is, block rigidity is not improved if the block is divided into small pieces by sipes.

  In addition, when the average sipe distance is larger than 7.9 mm or the average pitch length is smaller than 19.2 mm, the sipe distance increases and the block rigidity increases, but the number of sipe decreases too much and sipe edge can be exhibited Disappear and the sipe edge effect becomes too small. In addition, the pitch length becomes small, and the rigidity of each block becomes too small. As a result, the total edge effect is reduced and the block stiffness is not improved.

  In addition, when the average sipe distance is smaller than 3.4 mm or smaller than the average pitch length 19.2 mm, the sipe edge component increases, but the sipe distance becomes too small and the block is divided into small pieces, so that the block rigidity is increased. The block edge effect becomes too small because the pitch length is too small and the block stiffness is too small. Therefore, the block rigidity is too small, and the total edge is also reduced.

  In addition, when the average sipe distance is larger than 7.9 mm or the average pitch length is larger than 44.6 mm, the sipe distance increases and the rigidity of the block increases, but the number of sipe decreases excessively and the sipe edge can not be exhibited , The sipe edge effect becomes too small. Also, if the pitch length is too large, the number of pitches decreases, so the block edge effect becomes too small. Also, no matter how large the pitch length is, block rigidity is not improved if the block is divided into small pieces by sipes.

In addition, the tire width SEC (hereinafter the same) of passenger car tires (Passenger car tire) under the standards of JATAMA (or similar standards such as ETRTO, TRA, etc.) is 165, 175, 185, 195, 205, 215, 225, For standard tire sizes such as 235, 245 and 255 (hereinafter standard tire sizes), the average sipe spacing and average pitch length are
4.2 mm ≦ h ≦ 6.3 mm
23.6 mm ≦ L ≦ 35.4 mm
It is more preferable to The tire width SEC is 195 (mm) in the case of 195 / 65R15.

For standard tire sizes, the average sipe spacing and average pitch length of the central land block is
3.7 mm ≦ h ≦ 5.6 mm
23.6 mm ≦ L ≦ 35.4 mm
It is preferable to

For standard tire sizes, the average sipe spacing and average pitch length of the shoulder land block is
4.5 mm ≦ h ≦ 6.8 mm
23.6 mm ≦ L ≦ 35.4 mm
It is preferable to

For standard tire sizes, the average sipe spacing and average pitch length of the second land block is
4.1 mm ≦ h ≦ 6.1 mm
23.6 mm ≦ L ≦ 35.4 mm
It is preferable to

  By satisfying such a relationship, the sipe interval and the pitch length become optimum, and by appropriately reducing the number of sipe, the block stiffness is increased and the pitch length is appropriately reduced, thereby the number of pitches and the number of blocks. By increasing the block edge effect, the total edge effect can be improved while improving the block rigidity. In addition, it is as having mentioned above about the fault in case an average sipe interval and an average pitch length remove | deviate from the said range.

In addition, in the case of large tire sizes (hereinafter referred to as large SEC tire sizes) having a tire width SEC of 265, 275, 285, 295, 305, which is in the standard of JATAMA, the average sipe interval and average pitch length are
6.3 mm <h ≦ 7.9 mm
35.4 mm <L ≦ 44.6 mm
It is more preferable to

For large SEC tire sizes, the average sipe spacing and average pitch length of the central land block is
5.6 mm <h ≦ 7.1 mm
35.4 mm <L ≦ 44.6 mm
It is preferable to

For large SEC tire sizes, the average sipe spacing and average pitch length of the shoulder land blocks are
6.8 mm <h ≦ 8.5 mm
35.4 mm <L ≦ 44.6 mm
It is preferable to

For large SEC tire sizes, the average sipe spacing and average pitch length of the second part land block is
6.1 mm <h ≦ 7.7 mm
35.4 mm <L ≦ 44.6 mm
It is preferable to

  Thereby, in the tire of the tire size, the total edge effect can be improved while improving the block rigidity.

In addition, in the case of small tire sizes (hereinafter referred to as small SEC tire sizes) having a tire width SEC of 135, 145, 155 such as the JATAMA standard, the average sipe interval and the average pitch length are
3.4 mm ≦ h <4.2 mm
19.2 mm ≦ L <23.6 mm
It is more preferable to

For small SEC tire sizes, the average sipe spacing and average pitch length of the central land block is
3.0 mm ≦ h <3.7 mm
19.2 mm ≦ L <23.6 mm
It is preferable to

For small SEC tire sizes, the average sipe spacing and average pitch length of the shoulder land blocks are
3.7 mm ≦ h <4.5 mm
19.2 mm ≦ L <23.6 mm
It is preferable to

For small SEC tire sizes, the average sipe spacing and average pitch length of the second part land block is
3.3 mm ≦ h <4.1 mm
19.2 mm ≦ L <23.6 mm
It is preferable to

  Thereby, in the tire of the tire size, the total edge effect can be improved while improving the block rigidity.

As described above, (average block edge component Dball / average sipe edge component Dsall) / average block stiffness G preferably satisfies 2.20 ≦ (Dball / Dsall) /G≦4.00. If (Dball / Dsall) / G is less than 2.20 (mm) ³ / N, the sipe edge component becomes very large but the block edge component becomes remarkably lower than the block rigidity of the average land block. This is because the number of sipes increases, the sipe interval decreases, and the block stiffness decreases too much.

On the other hand, when (Dball / Dsall) / G exceeds 4.00 (mm) ³ / N, the block edge component becomes very large but the sipe edge component significantly decreases with respect to the block rigidity of the average land block. I will. This is because the number of sipes decreases, the sipe interval increases, and the block stiffness increases too much.

  The widthwise sipe may be inclined with respect to the tire circumferential direction (tire equator line CL) as long as it extends in the tire width direction. This is because an edge component in the tire circumferential direction is generated.

  As described above, the average block edge component Dball / average sipe edge component Dsall is preferably 0.15 ≦ (Dball / Dsall) ≦ 0.48. When Dball / Dsall is less than 0.15, the sipe edge component becomes very large, but the block edge component is significantly reduced. This is because the number of sipes increases, the sipes interval decreases, and the block rigidity of the land block decreases too much.

  On the other hand, when Dball / Dsall exceeds 0.48, although the block edge component becomes very large, the sipe edge component is significantly reduced. This is because the number of sipes decreases, the sipes interval increases, and the block rigidity of the land block becomes too large.

  As described above, the average sipe interval hs of the shoulder land block and the average sipe spacing hc of the center land block are preferably 1.05 ≦ (hs / hc) ≦ 4.00. If hs / hc is less than 1.05, the sipe interval of the shoulder land block decreases, the number of sipes increases, and the block stiffness of the land block becomes too low. Also, although the sipe edge component becomes large, the block edge component becomes too low.

  On the other hand, when hs / hc exceeds 4.00, the sipe interval of the shoulder land block increases, the number of sipe decreases, and the block edge component increases but the sipe edge component decreases too.

  In addition, as described above, other numerical ranges for the pitch and sipes described above are also defined in order to achieve compatibility between the block rigidity of the land block and the edge component. It is compatible with the wear performance on a high level.

(4.5) Evaluation test Next, the method and the result of the evaluation test conducted to confirm the relationship between the average sipe interval and the average pitch length will be further described.

  Table 1 shows the specifications and test results (on-ice brake performance and wear resistance performance) of pneumatic tires (studless tires) according to Comparative Examples and Examples. Table 2 shows the specifications and test results (on-ice brake performance and wear resistance performance) of (studless tire) according to the conventional example, the comparative example and the example.

(4.5.1) Basic configuration of evaluation test tire and test conditions The sizes and test conditions of the pneumatic tire used for the evaluation test are as follows.

-Tire size: 195/65 R15
・ Use rim size: 6J × 15
・ Set air pressure: 240 kPa (front and rear wheels)
-Wearing vehicle: Antilock brake (ABS) wearing vehicle In addition, the tread pattern used the shape shown in FIG. With regard to “ice braking performance”, in the ice road surface test course, the distance from the speed of 20 km / h to the sudden braking (ABS operation) and the time to stop (braking distance) at new tire and each stage after running-in Is measured seven times, and five values excluding the maximum value and the minimum value are averaged. Furthermore, the tire according to the conventional example (comparative example 1) is indexed as 100. The larger the value, the shorter the braking distance and the higher the braking performance on ice.

  The “wear resistance performance” was evaluated based on the remaining groove depth after traveling a 10,000-km road on an asphalt-paved road surface by mounting a tire to be tested on a vehicle equipped with two occupants. Specifically, the residual groove depth of the tire according to the conventional example (comparative example 1) is indexed as 100. The larger the value is, the deeper the residual groove depth is and the higher the wear resistance performance is.

(4.5.2) Evaluation Test Results As shown in Table 1, in the tires according to the examples (No. 2 to No. 8), the "on-ice brake performance" and the "wear resistance performance" are both improved. In particular, in No. 4 to No. 6, both performances are well-balanced and significantly improved.

  In addition, as shown in Table 2, Example 1 can be obtained by setting the relationship (hs / hc) of the sipe interval between the shoulder land block (shoulder portion) and the center land block as described above. The tires according to No. 5 to 5 are improved in the "on-ice brake performance" and the "wear resistance performance" as compared with the tire according to the conventional example.

  As the test results in Tables 1 and 2 show, it is important to increase the average pitch length and the average sipe distance in the case where the "abrasion resistance performance" dominates. On the other hand, in order to make the "ice brake performance" superior while improving the wear resistance performance, it is not necessary to simply increase the average pitch length and the average sipe interval, and both the average pitch length and the average sipe interval It is important to design a well-balanced

  This is because, as described above, in recent vehicles, ABS is almost standard installation, and ABS operates relatively more than a region where slip ratio is large such that the tire is completely locked and the surface of the ice is slid. The braking is repeated in the region where the slip ratio is small (that is, the region where the coefficient of friction (μ) is high), and in such a case, the block rigidity of the land block is increased to a certain extent rather than forming a large amount of sipes. By securing it, it is also for improving the braking performance on ice.

(5) Other Embodiments The contents of the present invention have been described above according to the examples, but the present invention is not limited to these descriptions, and various modifications and improvements are possible. It is obvious to the trader.

  For example, in the embodiment described above, the central land portion row 200 is provided at a position including the tire equator line CL, and the V-shaped land portion row 100 is provided outside the central land portion row 200 in the tire width direction. The land portion row 200 may not necessarily be provided at such a position. Also, the V-shaped land portion row 100 may be provided at a position including the tire equator line CL.

  Furthermore, the positions of the shoulder land portion row 300 in and the shoulder land portion row 300 out are not limited to the shoulder region, and may be provided in the second region or the like.

  Further, in the above-described embodiment, both the sipe 130, 140 and the end slope groove 150 are formed in the V-shaped land portion block 101, but only one of the sipe 130, 140 or the end slope groove 150 It may be formed.

  Furthermore, in the embodiment described above, the circumferential dimension of the V-shaped land block 101 is larger than the width dimension of the V-shaped land block 101, but the circumferential dimension may be the same as the width dimension.

  While the embodiments of the present invention have been described above, it should not be understood that the statements and drawings that form a part of this disclosure limit the present invention. Various alternative embodiments, examples and operation techniques will be apparent to those skilled in the art from this disclosure.

10, 10A pneumatic tire, 20 treads, 30, 40, 50, 60 circumferential grooves, 61 circumferential grooves, 62 inclined lug grooves, 70 lug grooves, 70b groove bottom, 80 lug grooves, 100V land portion row, 100a , 100b, 100c, 100d, 100g, sidewall, 101, 101A, 101B V-shaped land block, 110 convex portion, 110a most convex portion, 111, 112 convex portion side wall portion, 120 concave portion, 120a most concave portion, 121, 122 recessed side wall, 130 sipes, 131 ends, 140 sipes, 141 communicating sipes, 141a ends, 142 communicating sipes, 150 end slope grooves, 151 ends, 160 width direction slope grooves, 161 slope grooves, 162 slope grooves, 163 bend, 170 notch recess, 200 central land row, 201, 202 land row, 210, 210P land block, 210a, 210b, 210c side wall, 220 end slope groove, 220c side wall, 221 end, 230 sipes , 231 communicating sipes, 240 notched grooves, 241 tips, 260 land blocks, 270 crossing inclined grooves, 271 first groove width, 272 second groove width, 273 ridged groove, 280 End sloped groove, 281 end, 290 sipe, 300 in, 300 out shoulder land row, 310 land block, 310 a side wall, 310 b side wall, 320 circumferential sipe, 321 straight portion, 322 straight portion, 323 crest, 330 width Direction sipe 331, 332 end, 340 width direction sipe, 341 end, 351, 352 circumferential straight sipe, 352a, 352b end, 360 step, 361 raised bottom, 362 end, 380 zigzag surface, A1, A2 amplitude, CL tire equatorial line, CT center, W1, W2 circumferential dimensions

Claims (8)

A circumferential groove extending in the tire circumferential direction and a lug groove extending in the tire width direction are formed,
The tire is provided with a composite land portion row defined by the circumferential groove and the lug groove and configured by a first land portion row and a second land portion row provided along the tire circumferential direction,
The first land section row and the second land section row are adjacent in the tire width direction,
The first land section row is configured by a first block, and the second land section row is configured by a second block,
The first block is formed with a first inclined groove which is inclined with respect to the tire width direction and which is opened in a side wall on the second land portion row side.
The second block is formed with a second inclined groove which is inclined in the same direction as the first inclined groove and is opened on a side wall opposite to the first land portion row side.
The first inclined groove is a first end inclined groove having one end terminating in the first block,
The second inclined groove is a second end inclined groove having one end terminating in the second block,
Between the second block adjacent to the first block in the tire width direction, there is formed a cross inclined groove which is inclined in the same direction as the first end inclined groove and which divides the adjacent second block,
A total area of the first end sloped groove, the second end sloped groove and the transverse sloped groove in a contact surface with the road surface of the tire is a groove total area S1.
The total area of lands and grooves from one end in the tire width direction of the composite land portion row to the other end in the tire width direction of the composite land portion row is a combined land portion row total area S2 If
The tire whose S1 / S2 is 0.05 or more and 0.25 or less. A plurality of sipes are formed in the first block and the second block so as to extend at an angle to the tire width direction,
The spacing in the circumferential direction of the sipes adjacent in the tire circumferential direction in the first block is 3.3 mm or more and 10.0 mm or less,
2. The tire according to claim 1, wherein an interval in a circumferential direction of the sipe adjacent in a tire circumferential direction in the second block is 4.4 mm or more and 10.0 mm or less. The negative ratio of the first block is 8.9% or more and 20.7% or less.
The tire according to claim 1 or 2, wherein the negative rate of the second block is 11.8% or more and 27.4% or less.   The tire according to claim 1 or 2, wherein an average negative percentage of the first block and the second block adjacent to the first block in the tire width direction is 13.2% or more and 30.8% or less. A plurality of sipes are formed in the first block and the second block so as to extend at an angle to the tire width direction,
The inclination angle of the sipe with respect to the tire width direction in the second block, the inclination angle of the second end inclined groove and the inclination angle of the cross inclined groove are the inclination angle of the sipe with respect to the tire width direction in the first block The tire according to claim 1, which is equal to or more than the inclination angle of the first end inclined groove.   The tire according to claim 5, wherein the first end sloped groove, the second end sloped groove and the cross sloped groove are inclined in a direction opposite to the sipe with respect to the tire width direction. The first block is formed with a notched groove opening in a side wall opposite to the second land portion row side and in the tire width direction,
The tire according to any one of claims 1 to 6, wherein the first end inclined groove and the notch groove are located on an extension along the transverse inclined groove.   The tire according to any one of claims 1 to 7, wherein at least a part of the composite land portion row is provided in a center region including a tire equator line.

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