JP5092593B2 - Pneumatic tire - Google Patents

Description

  The present invention is mounted on a general passenger car, and is divided on the tread surface by a plurality of vertical grooves extending along the tire circumferential direction, a plurality of horizontal grooves extending along the tire width direction, and the vertical grooves and the horizontal grooves. The present invention relates to a pneumatic tire in which a plurality of blocks and a plurality of sipes extending along the tire width direction are provided on the blocks.

  In a pneumatic tire for snowy and snowy roads, in order to improve the performance on ice, a block is formed by a main groove and a lug groove, and a sipe is provided in the block, and this sipe is three-dimensional to prevent the block from falling down. It has been proposed to have a shape.

  An example of a sipe having a three-dimensional shape is described in Patent Document 1 below. In the pneumatic tire described in Patent Document 1, a plurality of vertical grooves extending in the tire circumferential direction and a plurality of horizontal grooves extending in the tire width direction are provided in the tread portion, and a plurality of blocks are formed by the vertical grooves and the horizontal grooves. This block is provided with a plurality of sipes extending in the tire width direction on the block, and the sipe is formed in a zigzag shape on the tread surface, and is bent in the tire circumferential direction at two or more locations in the tire radial direction inside the block. A continuous bent portion is formed, and a zigzag shape having an amplitude in the tire radial direction is formed at the bent portion.

Japanese Patent Laid-Open No. 2005-126055

  In the conventional pneumatic tire described in Patent Document 1 described above, a block is formed by a main groove and a lug groove, and a three-dimensional sipe is provided in the block, thereby improving the performance on ice and the block. Can be prevented from falling down.

  By the way, in recent years, higher output of vehicles has been achieved, and further improvement in block rigidity is desired after ensuring high performance on ice. In this case, it is conceivable to increase the block rigidity by reducing the number of sipes provided in the block or increasing the hardness of the rubber to be used, but this reduces the performance on ice.

  The present invention is intended to solve such problems, and provides a pneumatic tire that improves the handling stability by increasing the block rigidity during braking, driving, and turning in a vehicle. For the purpose.

In order to solve the above-described problems and achieve the object, the pneumatic tire of the invention of claim 1 includes a plurality of longitudinal grooves extending along the tire circumferential direction and a plurality of extending along the tire width direction on the tread surface. And a plurality of blocks divided by the vertical grooves and the horizontal grooves, and a pneumatic tire provided with a plurality of sipes extending along the tire width direction in the blocks, the sipe has a zigzag shape on a tread surface. None, a plurality of radially bent portions that are bent in the tire circumferential direction at two or more locations in the tire radial direction are formed in parallel in the block, and the width that is bent in the tire circumferential direction at two or more locations in the tire width direction direction bent portion is formed by a plurality parallel, the width direction bent portion is formed in a zigzag shape having an amplitude in the tire radial direction, the radial flexures, Sai from the tread surface A radial vertical bend extending parallel to the tire radial direction toward the bottom, and a radial inclined bend extending continuously to the radial vertical bend at a predetermined angle in the tire width direction and extending to the sipe bottom. It is characterized by having .

In the pneumatic tire of the second aspect of the invention, the radially inclined bent portion is inclined in the tire width direction with respect to a straight line along the tire radial direction, and the inclination angle e is set to 5 degrees or more and 30 degrees or less. It is characterized by being.

In the pneumatic tire of the invention of claim 3 , the width t of the sipe is set to 0.3 mm ≦ t ≦ 1.0 mm, and the amplitude a in the tire circumferential direction in the sipe is set to 0.5 mm ≦ a ≦ 4.0 mm. The pitch b in the tire width direction of the radially inclined bent portion is set to a ≦ b ≦ 4a.

In the pneumatic tire of the fourth aspect of the invention, the pitches b1 and b2 in the tire width direction of the adjacent radially inclined bent portions are set to different pitches, and when b1> b2, the pitch b1 is 1.5a ≦ b1 ≦. 6a, and the pitch b2 is set to a ≦ b2 ≦ 4a.

In the pneumatic tire according to the invention of claim 5 , the tread pattern is set in a shape symmetrical with respect to the tire equatorial plane in the tire width direction, and the sipe is formed in at least a block provided in a shoulder portion, and the tread surface side The distal end side of the radially inclined bent portion extending in the direction is inclined toward the outer side in the tire width direction.

In the pneumatic tire according to claim 6 , the tread pattern is set to be asymmetric in the tire width direction with respect to the tire equatorial plane, and the sipe is formed in a block provided at least on a shoulder portion on the outer side of the tire, The distal end side of the radially inclined bent portion extending toward the tread surface is inclined toward the tire outer side.

  According to the pneumatic tire of the first aspect of the invention, the tread surface is divided by the plurality of vertical grooves extending along the tire circumferential direction, the plurality of horizontal grooves extending along the tire width direction, and the vertical grooves and the horizontal grooves. A plurality of blocks, and a plurality of sipes extending along the tire width direction on the block. The sipe is zigzag on the tread surface and bent in the tire circumferential direction at two or more locations in the tire radial direction inside the block. A plurality of radially bent portions are arranged in parallel, and a plurality of widthwise bent portions that are bent in the tire circumferential direction at two or more locations in the tire width direction are arranged in parallel, and the widthwise bent portions are formed in a zigzag shape having an amplitude in the tire radial direction. A radially inclined bent portion that is inclined at a predetermined angle in the tire width direction is provided as the radially bent portion.

  Therefore, by forming the radial direction bending portion and the width direction bending portion that are bent in the tire circumferential direction inside the block, deformation of the block during braking or driving of the vehicle can be suppressed, and the width direction bending portion is It is formed in a zigzag shape with amplitude in the tire radial direction, and the radial bent portion is provided with a radially inclined bent portion that is inclined at a predetermined angle in the tire width direction, thereby suppressing deformation of the block during turning. As a result, it is possible to improve the steering stability by increasing the block rigidity at the time of braking, driving and turning in the vehicle while maintaining the performance on ice.

Further , according to the pneumatic tire of the first aspect of the present invention, the radial bent portion is formed on the radial vertical bent portion extending in parallel to the tire radial direction from the tread surface toward the sipe bottom, and the radial vertical bent portion. Since it is configured with a radially inclined bent portion that continuously extends to the sipe bottom, the rigidity in the tire width direction is increased by the radially inclined bent portion, so that deformation of the block during turning can be suppressed.

According to the pneumatic tire of the second aspect of the invention, the radially inclined bent portion is inclined in the tire width direction with respect to a straight line along the tire radial direction, and the inclination angle e is set to 5 degrees or more and 30 degrees or less. Therefore, by setting the inclination angle e of the radially inclined bent portion to an appropriate value, the angle with respect to the surface in the tire width direction is increased, and the surfaces partitioned by sipes are in contact with each other in the input in the tire width direction. Supporting with a large force, the block rigidity can be improved. In this case, when the inclination angle e of the radially inclined bent portion is larger than 30 degrees, it becomes difficult to manufacture a sipe, and when the inclination angle e is smaller than 5 degrees, the rigidity in the tire width direction is not sufficiently improved.

According to the pneumatic tire of the invention of claim 3 , the sipe width t is set to 0.3 mm ≦ t ≦ t 1.0 mm, and the amplitude a in the tire circumferential direction in the sipe is set to 0.5 mm ≦ a ≦ 4.0 mm. Since the pitch b in the tire width direction of the radially inclined bent portion is set to a ≦ b ≦ 4a, the sipe width t, the tire circumferential amplitude a in the sipe, and the radially inclined bent portion in the tire width direction are set. By setting the pitch b to an appropriate value, it is possible to improve block rigidity while ensuring high on-ice performance and on-snow performance, and it is possible to suppress deterioration of mold release characteristics due to sipes.

According to the pneumatic tire of the fourth aspect of the invention, the pitches b1 and b2 in the tire width direction of the adjacent radially inclined bent portions are set to different pitches, and when b1> b2, the pitch b1 is 1.5a ≦ b1. ≦ 6a and pitch b2 is set to a ≦ b2 ≦ 4a, so that high rigidity on ice and performance on snow can be secured, and lock rigidity can be improved, and mold release for producing sipe Can be improved.

According to the pneumatic tire of the fifth aspect of the invention, the tread pattern is set in a shape symmetrical to the tire equatorial plane in the tire width direction, and the sipe is formed at least on the block provided in the shoulder portion, and on the tread surface side. Since the distal end side of the extending radially inclined bent portion is inclined toward the outer side in the tire width direction, when the tread pattern has a symmetrical shape in the tire width direction, the radially inclined bent portion in the shoulder portion is the outer side in the tire width direction. By inclining in the direction, the strength can be improved with respect to the input from the outside in the tire width direction, and the turning performance can be improved.

According to the pneumatic tire of the sixth aspect of the invention, the tread pattern is set to be asymmetric in the tire width direction with respect to the tire equatorial plane, and the sipe is formed on the block provided at least on the shoulder portion on the outer side of the tire. Since the front end side of the radially inclined bent portion extending toward the surface side is inclined toward the tire outer side, when the tread pattern has an asymmetric shape in the tire width direction, the radially inclined bent portion in the shoulder portion on the tire outer side is the tire outer side. By inclining toward, strength can be improved with respect to input from the outside of the tire, and turning performance can be improved.

  Below, the example of the pneumatic tire concerning the present invention is described in detail based on a drawing. Note that the present invention is not limited to the embodiments.

  FIG. 1 is a plan view of a tread portion representing a pneumatic tire according to a first embodiment of the present invention, FIG. 2 is a schematic cross-sectional view of a shoulder block in the pneumatic tire of the first embodiment, and FIG. -III sectional view, FIG. 4 is a IV-IV sectional view of FIG. 2, FIG. 5 is a VV sectional view of FIG. 2, and FIG. 6 shows a sipe shape of a shoulder block in the pneumatic tire of Example 1. FIG.

  In the following description, the tire width direction is a direction parallel to the rotation axis of the pneumatic tire, and the inner side in the tire width direction is a direction toward the equator plane (equator line) in the tire width direction. The outward in the tire width direction is the direction opposite to the direction toward the equator plane (equatorial line) in the tire width direction. Further, the tire radial direction is a direction orthogonal to the rotation axis of the pneumatic tire, and the tire circumferential direction is a direction of rotation about the rotation axis of the pneumatic tire. Further, the inside of the tire is a direction that is located inside the vehicle body when the pneumatic tire is assembled to a regular rim and attached to the vehicle body, and the outside of the tire is a direction that is located outside the vehicle body at this time. It is.

  In Example 1, as shown in FIG. 1, the pneumatic tire 11 includes a tread portion, a shoulder portion, sidewall portions, and bead portions that are continuous on both sides thereof. The tread portion is formed on the outermost side in the tire radial direction, and comes into contact with the road surface when the surface of the tread portion, that is, a vehicle (not shown) on which the pneumatic tire 11 is mounted travels. The surface is formed as a tread surface 12. The tread surface 12 is provided with a pair of left and right grounding ends 13 at predetermined positions on the outer side in the tire width direction with respect to the equator line O1. In the pneumatic tire 11 of the present embodiment, the tread pattern is set to be asymmetric in the tire width direction with respect to the tire equatorial plane O1, and in FIG. 1, the left side is the tire inner side, and the right side is the tire outer side. It has become.

  The pneumatic tire 11 is provided with a plurality of main grooves extending along the tire circumferential direction on the tread surface 12, that is, one first main groove 21 and two second main grooves 22a and 22b. The first main groove 21 and the second main grooves 22a and 22b are straight main grooves parallel to the equator line, and the second main groove 22a is formed thicker than the second main groove 22b. A plurality of lug grooves 23 having one end communicating with the first main groove 21 and extending in the tire width direction are provided at predetermined intervals in the tire circumferential direction on the tire outer side (right side in FIG. 1) of the first main groove 21. It has been. Also, a lug groove 24 whose one end communicates with the second main groove 22a and bends in an L shape and one end communicates with the second main groove 22a on the tire outer side of the second main groove 22a located on the tire inner side. A plurality of lug grooves 25 extending in the tire width direction are alternately provided at predetermined intervals in the tire circumferential direction. In this case, the L-shaped lug grooves 24 communicate with each other so as to intersect the adjacent lug grooves 25 and lug grooves 24. Furthermore, a lug groove 26 having one end communicating with the first main groove 21 and the other end communicating with the lug groove 24 is predetermined in the tire circumferential direction inside the tire in the first main groove 21 (left side in FIG. 1). A plurality are provided at intervals.

  In this embodiment, three main grooves 21, 22a and 22b extending along the tire circumferential direction are provided on the tread surface 12, and each main groove 21, 22a and 22b is a longitudinal groove of the present invention. Yes. In this case, the number of longitudinal grooves is not limited to three, and two or four or more may be provided.

  In addition, a plurality of lug grooves 27 whose one end portion communicates with the second main groove 22a and extends to the shoulder portion in the tire width direction are provided at predetermined intervals in the tire circumferential direction inside the tire in the second main groove 22a located on the tire inner side. Is provided. A plurality of shoulder blocks 31 are formed by being divided by the second main grooves 22a and the plurality of lug grooves 27, and sipes 32 extending along the tire width direction are formed on the shoulder blocks 31 in the tire circumferential direction. Are provided in plurality. Further, a plurality of lug grooves 28 having one end portion communicating with the second main groove 22b and extending to the shoulder portion in the tire width direction are provided at predetermined intervals in the tire circumferential direction on the tire outer side of the second main groove 22b located on the tire outer side. Is provided. A plurality of shoulder blocks 33 are formed by being divided by the second main grooves 22b and the plurality of lug grooves 28, and sipes 34 extending along the tire width direction are formed on the shoulder blocks 33 in the tire circumferential direction. Are provided in plurality.

  In the present embodiment, a plurality of lug grooves 27 and 28 extending in the tire width direction from the tread surface 12 to the shoulder portion are provided, and each lug groove 27 and 28 is a lateral groove of the present invention. In this case, it is preferable to employ a pitch variation structure in which the lateral grooves are arranged while changing the pitch length in the tire circumferential direction.

  Here, the sipe 34 provided in the shoulder block 33 outside the tire will be described in detail.

  In the pneumatic tire 11 of this embodiment, as shown in FIGS. 2 to 6, the sipe 34 has a zigzag shape along the tire width direction W on the tread surface 12, and the tire diameter is within the shoulder block 33. A plurality of radial bending lines (radial bending portions) 41 and 42 that are bent in the tire circumferential direction C at two or more locations in the direction D are formed in parallel, and at two or more locations in the tire width direction W, the tire circumferential direction C A plurality of width direction bend lines (width direction bend portions) 43 and 44 that are bent in parallel are formed in parallel, and the width direction bend lines 43 and 44 are formed in a zigzag shape having an amplitude in the tire radial direction D. The direction bending lines 41 and 42 are radial inclination bending lines (radial inclination bending portions) that are inclined at a predetermined angle in the tire width direction W.

  That is, the sipe 34 is formed on the tread surface 12 along the tire width direction W and is formed in a zigzag shape having a predetermined amplitude in the tire circumferential direction C, and has two uneven surfaces facing each other. doing. A zigzag vertical surface 45 is formed adjacent to the tread surface 12 on one surface of the sipe 34. The radial bending line 41 extends in the tire radial direction D from the vertical surface portion 45 of the tread surface 12 through the inside of the shoulder block 33 to the sipe bottom portion 46, and in the tire circumferential direction C at two locations in the tire radial direction D. By bending, four bending points 47a, 47b, 47c, 47d are formed. On the other hand, the radial bending line 42 extends from the vertical surface portion 45 of the tread surface 12 to the sipe bottom portion 46 through the inside of the shoulder block 33 and is bent in the tire circumferential direction C at two locations in the tire radial direction D. Four bending points 48a, 48b, 48c, and 48d are formed. The radial bending lines 41 and 42 are alternately provided in the tire width direction W of the shoulder block 33. In this case, the bending points 47a, 47b, 47c, 47d of the adjacent radial bending lines 41, and The bending directions of the bending points 48a, 48b, 48c, and 48d of the radial bending line 42 are opposite directions.

  On the other hand, the width direction bending lines 43 and 44 extend in the tire width direction W along the tread surface 12 and are bent in the tire circumferential direction C at five locations in the tire width diameter direction W. The width direction bending lines 43 and 44 are formed in a zigzag shape having a predetermined amplitude by bending in the tire radial direction D. That is, the width direction bending line 43 passes through the bending points 48a, 47b, 48a, 47b... Of the radial direction bending lines 41, 42, and the bending points 48c, 47d, 48c of the radial direction bending lines 41, 42. , 47d. Further, the width direction bending line 44 passes through bending points 48b, 47c, 48b, 47c,... Of the radial direction bending lines 41, 42.

  Therefore, on one surface of the sipe 34, convex portions and concave portions are alternately formed along the tire radial direction D, and convex portions and concave portions are alternately formed along the tire width direction W. .

  Further, the radial inclined bending lines (radial bending lines) 41 and 42 extend from the vertical surface portion 45 of the tread surface 12 to the sipe bottom portion 46 and continuously incline at a constant angle in the tire width direction W. . In the pneumatic tire 11 of the present embodiment, the tread pattern is set to be asymmetric in the tire width direction W with respect to the tire equator line O1, and the sipe 34 is formed on a block 33 provided on a shoulder portion on the outer side of the tire. The distal end sides of the radially inclined bent lines 41 and 42 that are formed and extend from the sipe bottom 36 side to the tread surface 12 side are inclined toward the tire outer side. The radial inclined bending lines 41 and 42 are inclined in the tire width direction W with respect to a straight line along the tire radial direction D, and the inclination angle e is 5 degrees or more and 30 degrees or less (5 degrees ≦ e ≦ 30 degrees).

  The sipe 34 has a width t set to 0.3 mm ≦ t ≦ 1.0 mm. In the sipe 34, the amplitude a in the tire circumferential direction C is set to 0.5 mm ≦ a ≦ 4.0 mm. Further, in the sipe 34, the pitches b1 and b2 in the tire width direction W of the adjacent radially inclined bent lines 41 and 42 are set to different pitches. When b1> b2, the pitch b1 is 1.5a ≦ b1 ≦. The pitch b2 is set to a ≦ b2 ≦ 4a.

  Note that the sipe 34 described above has two uneven surfaces facing each other as described above. In the above description, the shape of one surface of the sipe 34 has been described, but the shape of the other surface is , The shape is the same except that the concavo-convex relationship is opposite to that of one surface. Therefore, the one uneven surface and the other uneven surface in the sipe 34 are engaged with each other, so that the deformation of the shoulder block 33 is suppressed and the collapse in the tire width direction W is suppressed.

  Further, a sipe 32 is also provided on the shoulder block 31 inside the tire, but this sipe 33 has a zigzag shape on the tread surface 12 and is not shown in the figure, but two locations in the tire radial direction D are inside the shoulder block 31. As described above, a plurality of radial bending lines bent in the tire circumferential direction C are formed in parallel, and a plurality of width bending lines bent in the tire circumferential direction C are formed in parallel at two or more locations in the tire width direction W. Although the widthwise bending line is formed in a zigzag shape having an amplitude in the tire radial direction D, the radial bending line is not inclined in the tire width direction W.

  Further, a plurality of sipes 35 and 36 having a zigzag shape along the tire width direction W are also provided in the block between the main grooves 21, 22 a and 22 b.

  Accordingly, at the time of braking, driving or turning in the vehicle, at each sipe 34 of the shoulder block 33, one uneven surface constituted by a plurality of radial direction bending lines 41 and 42 and width direction bending lines 43 and 44, The deformation of the shoulder block 33 is suppressed by meshing the other uneven surface. In this case, the width direction bending lines 43 and 44 of the sipe 34 are formed in a zigzag shape having an amplitude in the tire radial direction D, and the radial direction inclination bending lines 41 and 42 are inclined at a predetermined angle in the tire width direction W. Therefore, the rigidity when the shoulder block 33 falls to the inside of the tire is high.

  That is, in the sipe 34 provided on the shoulder block 33 outside the tire, the ends on the tread surface 12 side of the plurality of radial bending lines 41 and 42 are inclined toward the tire outer side. 2 against the stress from the right side), the shoulder block 33 falls more rigidly due to the wedge action. Therefore, when the vehicle turns, when the one concavo-convex surface of the sipe 34 is engaged with the other concavo-convex surface, the deformation of the shoulder block 33 toward the tire inner side is suppressed.

  Here, the steering stability in the conventional example and the first embodiment will be compared. In this case, as shown in Table 1 below, in the conventional pneumatic tire, the sipe has a zigzag shape along the tire width W on the tread surface, and at two or more locations in the tire radial direction D inside the shoulder block. Are formed in parallel with a plurality of radial bend lines that bend in the tire circumferential direction, and are formed in parallel with a plurality of width direction bend lines that are bent in the tire circumferential direction at two or more locations in the tire width direction. The line is formed in a zigzag shape having an amplitude in the tire radial direction. On the other hand, in the pneumatic tire 11 of Example 1, in addition to the configuration of the conventional pneumatic tire described above, the radial bending line is a radially inclined bending line that is inclined at a predetermined angle in the tire width direction. Is.

  When comparing the conventional example with Examples 1 and 1-1, the pneumatic tire 11 of each example in which the inclination angle e of the radial inclined bending lines 41 and 42 is set to 5 degrees ≦ e ≦ 30 degrees is as follows. It can be seen that the handling stability is greatly improved as compared with the conventional pneumatic tire.

In addition, the conditions and methods for implementing the steering stability evaluation are as follows.
1) Evaluation tire Tire size 205 / 55R16
Rim size 16 × 7JJ
Air pressure 210 [kPa] (after warm-up)
2) Evaluation method of tire handling stability When the tire of this example is mounted on a domestic 2.0-liter class front-wheel drive passenger car and the lane is changed while driving on the road surface, the driver steers by sensory evaluation. It can be evaluated that the stability is evaluated on a 100-point scale, and that 105 or more points have a sufficient effect.

  As described above, in the pneumatic tire 11 according to the first embodiment, the tread surface 12 includes the plurality of main grooves 22a and 22b extending along the tire circumferential direction and the plurality of lug grooves 27 and 28 extending along the tire width direction. The shoulder blocks 31 and 33 are divided, the shoulder blocks 31 and 33 are provided with a plurality of sipes 32 and 34 along the tire width direction, and the sipe 34 of the shoulder block 31 outside the tire is formed in a zigzag shape on the tread surface 12. A plurality of radial bending lines 41 and 42 that are bent in the tire circumferential direction at two or more locations in the tire radial direction are arranged in parallel inside the block 33 and are also bent in the tire circumferential direction at two or more locations in the tire width direction. 43 and 44 are arranged in parallel, and the width direction bending lines 43 and 44 are formed in a zigzag shape having an amplitude in the tire radial direction. , And the radial tilt bending lines inclined at a predetermined angle 42 in the tire width direction.

  Accordingly, by forming the radial direction bending lines 41 and 42 and the width direction bending lines 43 and 44 that are bent in the tire circumferential direction inside the shoulder block 33, deformation of the block 33 during braking or driving of the vehicle is suppressed. The radial bending lines 43 and 44 are formed in a zigzag shape having an amplitude in the tire radial direction, and the radial bending lines 41 and 42 are inclined at a predetermined angle in the tire width direction. As a result, the deformation of the block 33 at the time of turning can be suppressed. As a result, the rigidity of the block at the time of braking, driving, turning, etc. in the vehicle is increased while maintaining the performance on ice, thereby stabilizing the operation. It is possible to improve the performance.

  Further, in the pneumatic tire 11 of Example 1, the radially inclined bent lines 41 and 42 are continuously formed from the tread surface 12 to the sipe bottom 36 at a constant angle. Accordingly, the rigidity in the tire width direction is increased by the radially inclined bent lines 41 and 42, so that the deformation of the block 33 during turning can be suppressed.

  Further, in the pneumatic tire 11 of Example 1, the radially inclined bending lines 41 and 42 are inclined in the tire width direction with respect to the straight line along the tire radial direction, and the inclination angle e is 5 degrees or more and 30 degrees or less. Is set. Accordingly, by setting the inclination angle e of the radial inclined bending lines 41 and 42 to an appropriate value, the angle with respect to the surface in the tire width direction increases, and the surfaces partitioned by the sipes 34 with respect to the input in the tire width direction are It comes into contact and is supported with a large force, and the block rigidity can be improved. In this case, when the inclination angle e of the radial inclined bending lines 41 and 42 is larger than 30 degrees, it becomes difficult to remove the metal plate for forming the sipe 34 after vulcanization of the rubber, and it becomes difficult to manufacture the sipe 34. On the other hand, when the inclination angle e is smaller than 5 degrees, the improvement in rigidity in the tire width direction is insufficient.

  In the pneumatic tire 11 of Example 1, the width t of the sipe 34 is set to 0.3 mm ≦ t ≦ 1.0 mm, and the amplitude a in the tire circumferential direction at the sipe 34 is 0.5 mm ≦ a ≦ 4.0 mm. The pitch b in the tire width direction of the radially inclined bent lines 41 and 42 is set to a ≦ b ≦ 4a. Therefore, by setting the width t of the sipe 34, the amplitude a in the tire circumferential direction at the sipe 34, and the pitch b in the tire width direction of the radially inclined bending lines 41 and 42 to appropriate values, high performance on ice and performance on snow are ensured. In addition to improving the block rigidity, it is possible to suppress the deterioration of the mold releasability due to the sipe 34.

  Further, in the pneumatic tire 11 of Example 1, the pitches b1 and b2 in the tire width direction of the adjacent radially inclined bent lines 41 and 42 are set to different pitches, and when b1> b2, the pitch b1 is set to 1.5a. ≦ b1 ≦ 6a and the pitch b2 are set to a ≦ b2 ≦ 4a. Therefore, it is possible to improve the lock rigidity while ensuring high on-ice performance and on-snow performance, and to improve the mold release property of the mold for manufacturing the sipe 34.

  Further, in the pneumatic tire 11 of Example 1, the tread pattern is set to a shape asymmetric in the tire width direction with respect to the tire equatorial plane O1, and the sipe 34 is formed on the shoulder block 33 on the outer side of the tire, and on the tread surface 12 side. The leading ends of the extending radial slant bending lines 41 and 42 are inclined toward the tire outer side. Therefore, when the tread pattern has an asymmetric shape in the tire width direction, the radial inclined bending lines 41 and 42 in the shoulder block 33 on the tire outer side are inclined toward the tire outer side, so that the input from the tire outer side is prevented. The strength can be improved and the turning performance can be improved.

  In Example 1 described above, the sipe of the pneumatic tire of the present invention is applied to the sipe 34 of the shoulder block 33 outside the tire. However, the sipe 32 of the shoulder block 31 inside the tire and the sipe 35, 36 of the trad surface 12 are used. You may apply to. In this case, it is desirable to incline the tip end side of the radially inclined bent portion extending toward the tread surface side toward the outer side in the tire width direction.

  7 is a schematic cross-sectional view of a shoulder block in a pneumatic tire according to Example 2 of the present invention, FIG. 8 is a cross-sectional view taken along line VIII-VIII in FIG. 7, and FIG. 9 is a cross-sectional view taken along line IX-IX in FIG. . In addition, the same code | symbol is attached | subjected to the member which has the same function as what was demonstrated in the Example mentioned above, and the overlapping description is abbreviate | omitted.

  In Example 2, as shown in FIGS. 7 to 9, a shoulder block 53 is formed by a main groove and a lug groove on the tire outer side of the tread surface 52 of the pneumatic tire 51, and the shoulder block 53 has a tire width direction. A sipe 54 extending along the line is provided. The sipe 54 has a zigzag shape along the tire width direction W on the tread surface 52, and a radial bending line (bending in the tire circumferential direction C at two or more locations in the tire radial direction D inside the shoulder block 53 ( A plurality of radial direction bent portions (61, 62) are formed in parallel, and a plurality of width direction bent lines (width direction bent portions) 63, 64 that are bent in the tire circumferential direction at two or more locations in the tire width direction W are arranged in parallel. Is formed. And the width direction bending lines 63 and 64 are formed in a zigzag shape having an amplitude in the tire radial direction D. On the other hand, a radial vertical bend line (radial vertical bend portion) 61a in which the radial bend line 61 extends parallel to the tire radial direction D, and a predetermined angle in the tire width direction W with the radial vertical bend line 61a continuous. And a radially inclined bent line (radially inclined bent portion) 61b that is inclined at a predetermined angle with respect to the tire width direction W. It has become.

  That is, the sipe 54 is formed on the tread surface 52 along the tire width direction W and is formed in a zigzag shape having a predetermined amplitude in the tire circumferential direction, and has two uneven surfaces facing each other. ing. A zigzag vertical surface portion 65 is formed adjacent to the tread surface 52 on one surface of the sipe 54. The radial bending line 61 extends in the tire radial direction D from the vertical surface portion 65 of the tread surface 52 through the inside of the shoulder block 53 to the sipe bottom portion 66, and in the tire circumferential direction C at two locations in the tire radial direction D. By bending, four bending points 67a, 67b, 67c, 67d are formed. On the other hand, the radial bending line 62 extends from the vertical surface portion 65 of the tread surface 52 through the inside of the shoulder block 53 to the sipe bottom portion 66 and bends in the tire circumferential direction C at two locations in the tire radial direction D. Four bending points 68a, 68b, 68c, and 68d are formed. And the radial direction bending lines 61 and 62 are alternately provided in the tire width direction of the shoulder block 53, and in this case, each bending point 67a, 67b, 67c, 67d of the adjacent radial direction bending line 61 and the diameter are provided. The bending direction of each bending point 68a, 68b, 68c, 68d of the direction bending line 62 is the reverse direction.

  On the other hand, the width direction bending lines 63 and 64 extend in the tire width direction W along the tread surface 52 and are bent in the tire circumferential direction C at five locations in the tire width diameter direction W. The width direction bending lines 63 and 64 are formed in a zigzag shape that is bent in the tire radial direction D and has a predetermined amplitude. That is, the width direction bending line 63 passes through the bending points 68a, 67b, 68a, 67b... Of the radial direction bending lines 61, 62, and the bending points 67d, 68c, 67d of the radial direction bending lines 61, 62. Pass through ... Moreover, the width direction bending line 64 passes the bending points 68b, 67c, 68b, 67c... Of the radial direction bending lines 61, 62.

  Therefore, on one surface of the sipe 54, convex portions and concave portions are alternately formed along the tire radial direction D, and convex portions and concave portions are alternately formed along the tire width direction W. .

  Further, the radial inclined bending line 61b of the radial bending line 61 extends from the shoulder block 53 to the sipe bottom portion 66, and is continuously inclined at a constant angle in the tire width direction W. Further, a radial inclined bending line (radial bending line) 62 extends from the vertical surface portion 65 of the tread surface 52 to the sipe bottom portion 66 and is continuously inclined at a constant angle in the tire width direction W. In this case, the inclination angle of the radial inclination bending line 61b and the radial inclination bending line 62 is the same angle. In the pneumatic tire 51 of the present embodiment, the tread pattern is set to be asymmetrical in the tire width direction with respect to the tire equator line O1, and the sipe 54 is formed in a block 53 provided at a shoulder portion on the outer side of the tire. The distal end sides of the radially inclined bent lines 61b and 62 extending from the sipe bottom 66 side to the tread surface 52 side are inclined toward the tire outer side. And these radial direction inclination bending lines 61b and 62 incline in the tire width direction W with respect to the straight line along the tire radial direction D, and this inclination angle e is 5 degrees or more and 30 degrees or less (5 degrees ≤ e ≤ 30 degrees).

  The sipe 54 has a width t set to 0.3 mm ≦ t ≦ t1.0 mm. In the sipe 54, the amplitude a in the tire circumferential direction is set to 0.5 mm ≦ a ≦ 4.0 mm. Further, in the sipe 34, the pitch b of the radial bending lines 61a and 62 in the tire width direction is set to a ≦ b ≦ 4a, and the pitches b1 and b2 of the adjacent radial inclined bending lines 61b and 62 in the tire width direction are set. When b1> b2, the pitch b1 is set to 1.5a ≦ b1 ≦ 6a, and the pitch b2 is set to a ≦ b2 ≦ 4a.

  Note that the sipe 54 described above has two concavo-convex surfaces facing each other as described above. In the above description, the shape of one surface of the sipe 54 has been described, but the shape of the other surface is , The shape is the same except that the concavo-convex relationship is opposite to that of one surface. Therefore, the one uneven surface and the other uneven surface in the sipe 54 mesh with each other, so that the deformation of the shoulder block 53 is suppressed, and the collapse in the tire width direction is suppressed.

  Accordingly, at the time of braking, driving or turning in the vehicle, at each sipe 54 of the shoulder block 53, one uneven surface constituted by a plurality of radial direction bending lines 61 and 62 and width direction bending lines 63 and 64, The deformation of the shoulder block 53 is suppressed by meshing the other uneven surface. In this case, the widthwise bending lines 63 and 64 of the sipe 54 are formed in a zigzag shape having an amplitude in the tire radial direction, and the radially inclined bending lines 61b and 62 are inclined at a predetermined angle in the tire width direction. Therefore, the rigidity when the shoulder block 53 falls to the inside of the tire is high.

  That is, in the sipe 54 provided in the shoulder block 53 outside the tire, the ends on the tread surface 12 side of the plurality of radial bending lines 61 and 62 are inclined toward the tire outer side. 2 against the stress from the right side), the shoulder block 53 is more rigid due to the wedge action. Therefore, when the vehicle turns, when the one uneven surface of the sipe 54 and the other uneven surface mesh with each other, the deformation of the shoulder block 53 toward the tire inner side is suppressed.

  Here, the steering stability in the conventional example and the second embodiment will be compared. In this case, as shown in Table 2 below, in the conventional pneumatic tire, the sipe has a zigzag shape along the tire width direction on the tread surface, and at two or more locations in the tire radial direction inside the shoulder block. A plurality of radial bend lines that are bent in the tire circumferential direction are formed in parallel, and a plurality of width direction bend lines that are bent in the tire circumferential direction at two or more locations in the tire width direction are formed in parallel. Is formed in a zigzag shape having an amplitude in the tire radial direction. On the other hand, the pneumatic tire 51 of the second embodiment has a radial slant bend in which a part of the radial bend line is slanted at a predetermined angle in the tire width direction from the middle in addition to the configuration of the pneumatic tire of the conventional example described above. It is a line.

  When comparing the conventional example with Examples 2, 2-1, and 2-2, the pneumatic tire 51 of each example provided with the radially inclined bent lines 61a, 62 is the pneumatic tire of the conventional example. The pneumatic tires 51 of Examples 2-1 and 2-2 in which the steering stability is improved and the inclination angle e of the radial inclination bending lines 61a and 62 is set to 5 degrees ≦ e ≦ 30 degrees are as follows. It can be seen that the handling stability is greatly improved as compared with the conventional pneumatic tire.

  Thus, in the pneumatic tire 51 of Example 2, the shoulder block 53 is divided into the tread surface 52 by the plurality of main grooves and the plurality of lug grooves, and a plurality of sipes are formed along the tire width direction on the shoulder block 53. 54, the sipe 54 is formed in a zigzag shape on the tread surface 52, and a plurality of radial bending lines 61, 62 that are bent in the tire circumferential direction at two or more locations in the tire radial direction are arranged in the block 53, and the tire width A plurality of width-direction bending lines 63, 64 that are bent in the tire circumferential direction at two or more locations in the direction are juxtaposed, and the width-direction bending lines 63, 64 are formed in a zigzag shape having an amplitude in the tire radial direction. 61 is composed of a radial vertical bent line 61a extending in the tire radial direction and a radial inclined bent line 61b inclined at a predetermined angle in the tire width direction. The curve 62 has a radially inclined bend lines inclined at a predetermined angle in the tire width direction.

  Therefore, by forming the radial direction bending lines 61 and 62 and the width direction bending lines 63 and 64 that are bent in the tire circumferential direction inside the shoulder block 53, deformation of the block 53 during braking or driving of the vehicle is suppressed. The radial bending lines 63 and 64 are formed in a zigzag shape having an amplitude in the tire radial direction, and the radial bending lines 61 and 62 are inclined at a predetermined angle in the tire width direction. By using 61b and 62, the deformation of the block 53 at the time of turning can be suppressed, and as a result, the block rigidity at the time of braking, driving, turning, etc. in the vehicle can be increased while maintaining the performance on ice. Can improve the handling stability.

  Further, in the pneumatic tire 51 of the second embodiment, the radial bending line 61 includes a radial vertical bending line 61a extending in parallel to the tire radial direction from the tread surface 52 toward the sipe bottom 56, and the radial vertical bending line. It is configured by a radially inclined bent line 61b that extends continuously to 61a and extends to the sipe bottom 56 and is inclined at a predetermined angle in the tire width direction. Accordingly, the rigidity in the tire width direction is increased by the radially inclined bent line 61b, so that deformation of the block during turning can be suppressed.

  In each of the embodiments described above, in the pneumatic tires 11 and 51 of this embodiment in which the tread pattern has an asymmetric shape in the tire width direction with respect to the tire equator line O1, the sipes 34 and 54 are shoulders on the tire outer side. The tip end side of the radially inclined bending lines 41, 42, 61, 62 formed on the blocks 33, 53 provided in the section and extending toward the tread surfaces 12, 52 is inclined toward the tire outer side. Is not to be done. For example, in a pneumatic tire in which the tread pattern is symmetric with respect to the tire equatorial plane, the sipe is formed in blocks provided on the shoulder portions on both sides in the tire width direction, and the radial inclination extends to the tread surface side. What is necessary is just to comprise so that the front end side of a bending part may incline toward the tire width direction outer side. Accordingly, the strength can be improved with respect to the input from the outside in the tire width direction, and the turning performance can be improved.

  As described above, in the pneumatic tire according to the present invention, a sipe is configured by a plurality of radial bending lines and a width bending line, and the radial bending line is inclined at a predetermined angle in the tire width direction. This improves the steering stability by increasing the block rigidity during braking, driving, turning, etc., and is suitable for use in any type of pneumatic tire.

It is a top view of the tread part showing the pneumatic tire concerning Example 1 of the present invention. 3 is a schematic cross-sectional view of a shoulder block in the pneumatic tire of Example 1. FIG. FIG. 3 is a sectional view taken along line III-III in FIG. 2. It is IV-IV sectional drawing of FIG. It is VV sectional drawing of FIG. It is the schematic showing the sipe shape of the shoulder block in the pneumatic tire of Example 1. It is a schematic sectional drawing of the shoulder block in the pneumatic tire which concerns on Example 2 of this invention. It is VIII-VIII sectional drawing of FIG. It is IX-IX sectional drawing of FIG.

Explanation of symbols

11, 51 Pneumatic tire 12, 52 Tread surface 21 First main groove (vertical groove)
22a, 22b Second main groove (vertical groove)
27, 28 Lug groove 31, 33, 53 Shoulder block 32, 34, 54 Sipe 41, 42 Radial direction bending line, radial direction inclination bending line (radial direction bending part, radial direction inclination bending part)
43, 44 Width direction bending line (width direction bending part)
61 Radial bending line (radial bending part)
62 Radial direction bending line, radial direction bending line (radial direction bending part, radial direction bending part)
61a Radial vertical bending line (radial vertical bending part)
61b Radially inclined bent line (radially inclined bent portion)

Claims (6)

A plurality of vertical grooves extending along the tire circumferential direction on the tread surface, a plurality of horizontal grooves extending along the tire width direction, a plurality of blocks partitioned by the vertical grooves and the horizontal grooves, and a tire width direction on the blocks In the pneumatic tire provided with a plurality of sipes extending along the
The sipe has a zigzag shape on the tread surface, and a plurality of radially bent portions that are bent in the tire circumferential direction at two or more locations in the tire radial direction are formed in parallel inside the block. A plurality of widthwise bent portions that are bent in the tire circumferential direction at multiple locations are formed in parallel, and the widthwise bent portions are formed in a zigzag shape having an amplitude in the tire radial direction,
The radial bending portion is inclined at a predetermined angle in the tire width direction continuously to the radial vertical bending portion extending in parallel to the tire radial direction from the tread surface toward the sipe bottom. And a radially inclined bent portion extending to the bottom of the sipe . 2. The pneumatic tire according to claim 1 , wherein the radially inclined bent portion is inclined in a tire width direction with respect to a straight line along the tire radial direction, and the inclination angle e is set to 5 degrees or more and 30 degrees or less. Pneumatic tire characterized by being made. 3. The pneumatic tire according to claim 1 , wherein a width t of the sipe is set to 0.3 mm ≦ t ≦ 1.0 mm, and an amplitude a in the tire circumferential direction of the sipe is 0.5 mm ≦ a ≦ 4. The pneumatic tire is set to 0 mm, and the pitch b in the tire width direction of the radially inclined bent portion is set to a ≦ b ≦ 4a. The pneumatic tire according to claim 3, wherein pitches b1 and b2 in the tire width direction of the adjacent radially inclined bent portions are set to different pitches, and when b1> b2, the pitch b1 is 1.5a ≦ b1 ≦. The pneumatic tire is characterized by being set to 6a and the pitch b2 being set to a ≦ b2 ≦ 4a. The pneumatic tire according to any one of claims 1 to 4, wherein the tread pattern is set in a shape symmetrical with respect to the tire equatorial plane in the tire width direction, and the sipe is at least provided on a block provided in a shoulder portion. A pneumatic tire, characterized in that a distal end side of the radially inclined bent portion that is formed and extends toward the tread surface side is inclined outward in the tire width direction. 5. The pneumatic tire according to claim 1, wherein the tread pattern is set to be asymmetric in a tire width direction with respect to a tire equatorial plane, and the sipe is provided at least on a shoulder portion on the outer side of the tire. A pneumatic tire characterized in that a distal end side of the radially inclined bent portion that is formed in a block and extends toward the tread surface side is inclined toward the tire outer side.

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