JP5986789B2 - tire - Google Patents

Description

  The present invention relates to a tire.

  Conventionally, as shown in FIG. 1, in the tread portion 10, a protective belt layer 11 made of two protective belts 11A / 11B, a main crossed belt layer 12 made of two main crossed belts 12A / 12B, and two sheets There is known a heavy load tire 1 having a small crossing belt layer 13 composed of the small crossing belts 13A / 13B (see, for example, Patent Documents 1 and 2).

  As shown in FIG. 1, in such a tire 1, the main crossing belt layer 12 is disposed on the outer side in the tire radial direction of the small crossing belt layer 13, and the protective belt layer 11 is arranged in the tire radial direction of the main crossing belt layer 12. Arranged outside.

  For example, in such a tire 1, the angle formed by the cord constituting the small crossing belt layer 13 and the tire circumferential direction L is 4 to 10 °, and the cord constituting the main crossing belt layer 12 and the tire circumferential direction L are The angle formed is 18 to 35 °, and the angle formed by the cord constituting the protective cross belt layer 11 and the tire circumferential direction L is 22 to 33 °.

  Therefore, in the tread portion 10 of the tire 1, in the region near the tire equator line CL (center region), compared to the region near the end in the tire width direction W (shoulder region), the cords constituting each belt layer The angle formed with the tire circumferential direction L is small.

Japanese Patent No. 4677307 Japanese Patent No. 4628080

  In the tire 1 described above, in a region where the angle formed by the cord constituting the belt layer and the tire circumferential direction L is large, the belt tension is small, and thus the region is greatly contracted in the tire circumferential direction L.

  As a result, when the tire 1 rotates, the region near the end in the tire width direction W in the tire circumferential direction L contracts greatly in the tire circumferential direction L, so that the region near the tire equator line CL in the tire circumferential direction L The length is longer than the length of the region near the end in the tire width direction W in the tire circumferential direction L.

  Therefore, when the tire 1 rotates, a force in the tire rotation direction (driving force) is generated in a region near the tire equator line CL, and a region in the direction opposite to the tire rotation direction is generated in a region near the end in the tire width direction W. Since a force (braking force) is generated, a shearing force is generated near the boundary between both regions.

  Further, when a load is applied to the tire 1 after an internal pressure is applied, the tire diameter is between a region in the vicinity of the tire equator line CL and a region in the vicinity of the end in the tire width direction W. Since the degree of deformation in the direction is different, a shearing force is generated near the boundary between the two.

  In particular, when such a tire 1 is mounted on a steering shaft, a force in the tire width direction W depending on the steering angle is applied, and when such a tire 1 is mounted on a shaft on which a braking force is applied, the braking force is applied. Is added, the shearing force is further increased.

  In particular, this phenomenon becomes remarkable in the heavy load tire 1 configured such that the length of the land portion in the tire width direction W is 30% or more of the length of the tread portion 10 in the tire width direction W.

  Therefore, the present invention has been made in view of the above-described problems, and it is possible to reduce the shearing force generated between the region near the tire equator line CL and the region near the end in the tire width direction W. The object is to provide a tire.

  The first feature of the present invention is that, in the tread portion, a circumferential groove extending in the tire circumferential direction or an end portion of the tread portion in the tire width direction, and a length in the tire width direction of the tread portion in the tire width direction. A tire having a plurality of land portions partitioned by a widthwise groove extending in the tire width direction and configured to be 30% or more of the length of the tire, wherein the widthwise groove is a tire equator line The gist is to have at least one bent portion configured to be bent in the opposite direction to the tire rotation direction on at least one side.

  In the first feature of the present invention, the belt layer includes a plurality of belt layers, and at least one of the bent portions is an end of the belt layer having the smallest angle between the cord constituting the belt layer and the tire circumferential direction. It may be provided in the vicinity of the position in the tire width direction corresponding to the portion.

  In the first feature of the present invention, the widthwise groove has at least two bent portions on at least one side of the tire equator line, and the widthwise groove is between the two bent portions. The flat portion may be formed so as to be substantially parallel to the tire width direction.

  1st characteristic of this invention WHEREIN: The circumferential direction fine groove which cross | intersects the said flat part and extends in the said tire circumferential direction may be provided.

  As described above, according to the present invention, it is possible to provide a tire capable of reducing the shearing force generated between the region near the tire equator line CL and the region near the end in the tire width direction W. it can.

It is sectional drawing orthogonal to a tire peripheral direction along the tire radial direction of the tire which concerns on the 1st Embodiment of this invention. It is a figure for demonstrating the belt structure of the tire which concerns on the 1st Embodiment of this invention. 1 is a plan view of a part of a tread surface in a tire according to a first embodiment of the present invention. It is a figure for demonstrating the effect which can show | play with the tire which concerns on the 1st Embodiment of this invention. It is a top view of a part of tread surface in a tire concerning modification 1 of the present invention. It is a top view of a part of tread surface in a tire concerning modification 2 of the present invention. It is a top view of a part of tread surface in a tire concerning modification 3 of the present invention. It is a top view of a part of tread surface in a tire concerning modification 4 of the present invention. It is a top view of a part of tread surface in a tire concerning modification 5 of the present invention. It is a top view of a part of tread surface in a tire concerning modification 6 of the present invention.

(First embodiment of the present invention)
A tire 1 according to a first embodiment of the present invention will be described with reference to FIGS. 1 to 4.

  FIG. 1 shows a cross-sectional view perpendicular to the tire circumferential direction along the tire radial direction of the tire 1 according to this embodiment, and FIG. 3 shows a plan view of a part of the tread surface in the tire 1 according to this embodiment. .

  In the present embodiment, a heavy load tire 1 will be described as an example of the tire 1, but the present invention is not limited to such a tire.

  As shown in FIG. 1, in the tire 1 according to the present embodiment, the length W2 of the land portion 40 in the tire width direction W is 30% or more of the length W1 of the tread portion 10 in the tire width direction W. It is configured.

  The tire 1 according to the present embodiment includes a plurality of belt layers. Specifically, as shown in FIGS. 1 and 2, the tire 1 according to the present embodiment includes a protective belt layer 11 including two protective belts 11 </ b> A / 11 </ b> B and two main crossing belts in the tread portion 10. The main crossing belt layer 12 made of 12A / 12B and the small crossing belt layer 13 made of two small crossing belts 13A / 13B are provided.

  As shown in FIGS. 1 and 2, in the tire 1, the main crossing belt layer 12 is disposed on the outer side in the tire radial direction of the small crossing belt layer 13, and the protection belt layer 11 is formed of the main crossing belt layer 12. It is arranged on the outer side in the tire radial direction.

  For example, as shown in FIG. 2, in such a tire 1, the angle formed by the cord constituting the small crossing belt layer 13 and the tire circumferential direction L is 4 to 10 °, and the cord constituting the main crossing belt layer 12 The angle formed by the tire circumferential direction L is 18 to 35 °, and the angle formed by the cord constituting the protective cross belt layer 11 and the tire circumferential direction L is 22 to 33 °.

  Further, as shown in FIG. 3, the tire 1 according to the present embodiment includes, in the tread portion 10, a circumferential groove 30 extending in the tire circumferential direction L or an end portion 10 </ b> E in the tire width direction W of the tread portion 10 and a tire width. A plurality of land portions 40 partitioned by the widthwise grooves 20 extending in the direction W are provided.

  Here, for example, the circumferential groove 30 preferably has a groove width of 10 mm or less, and the width direction groove preferably has a width of 50 mm or less. The land portion 40 may be provided with one or more circumferential narrow grooves (sipes) (circular narrow grooves 70 in FIGS. 8 and 10 to be described later) extending in the circumferential direction of 50 mm or less. Good.

  The depth in the tire radial direction of the circumferential narrow groove is shallower than the depth in the tire radial direction of the circumferential groove 30 and the width groove 20.

  Here, when paying attention to wear, the width of the circumferential groove 30 (the length in the tire width direction W) is preferably 10 mm or less because the land portions 40 support each other when force is applied.

  On the other hand, when paying attention to heat dissipation, the width of the circumferential groove 30 (the length in the tire width direction W) is preferably larger than 10 mm.

  In the tire 1 according to this embodiment, the length of the width direction groove 20 in the tire width direction W is configured to be 30% or more of the length W1 of the tread portion 10 in the tire width direction W.

  Furthermore, in the tire 1 according to the present embodiment, the pitch P of each land portion 40 (width direction groove 20) may be configured to be 50 mm or more.

  In the tire 1 according to the present embodiment, as shown in FIG. 3, the width direction groove 20 is configured to bend in at least one side of the tire equator line CL in a direction opposite to at least one tire rotation direction R. It is comprised so that it may have the bending part 50A / 50B.

  In the example of FIG. 3, the width direction groove 20 has one bent portion 50A on the left side of the tire equator line CL and one bent portion 50B on the right side of the tire equator line CL.

  Here, the width direction groove 20 may have one bent portion 50A (or 50B) only on the left side (or right side) of the tire equator line CL.

  Moreover, the width direction groove | channel 20 may be comprised so that it may have another bending part in addition to two bending part 50A / 50B shown in FIG.

  Moreover, all the width direction grooves 20 may be configured to have the above-described bent portion, or only a predetermined width direction groove 20 may be configured to have the above-described bent portion.

  In addition, as shown in FIG. 3, the width direction groove | channel 20 may be comprised so that it may continue in the tire equator line CL, and may be comprised so that it may not continue in the tire equator line CL.

  In the example of FIG. 3, the width direction groove 20 is continuous along the tire equator line CL, and is configured to bend in the tire rotation direction R along the tire equator line CL.

  Here, by the above-described bent portions 50A / 50B, a recess (concave portion) is formed on at least one kicking side of the land portions 40 arranged on both sides of the tire equator line CL.

  Further, the above-described bent portions 50A / 50B form protrusions (projections) on at least one of the land portions 40 arranged on both sides of the tire equator line CL.

  As shown in FIG. 3, the tire 1 according to the present embodiment has a directional pattern that specifies the rotation direction R of the tire 1. That is, in the tire 1 according to the present embodiment, it is assumed that the mounting direction of the tire 1 with respect to the wheel is determined.

  For example, in the tire 1 according to the present embodiment, the width direction groove 20 bent in the bent portions 50A / 50B is inclined by 0 ° to 80 ° with respect to the tire circumferential direction L in the plan view of the tread surface, and the tire width direction It may be formed so as to incline from 0 ° to 80 ° with respect to W.

  Here, in the region near the end portion 10E in the tire width direction W on the tread surface, the inclination angle of the width direction groove 20 with respect to the tire width direction W may be configured to be gentle.

  In such a case, in the tire 1 according to the present embodiment, the land portion 40 has an arrow-shaped shape in a plan view of the tread surface as shown in FIG.

  Further, in the tire 1 according to the present embodiment, as shown in FIGS. 1 and 3, the bent portions 50A / 50B are formed by the belt layer having the smallest angle between the cord constituting the belt layer and the tire circumferential direction L (that is, It may be provided in the vicinity of the position A in the tire width direction corresponding to the end of the small crossing belt layer 13).

  Here, “in the vicinity of the position A in the tire width direction” is, for example, a distance of 1/4 of the width of the tire 1 (the length in the tire width direction W) from the end portion 10E in the tire width direction W on the tread surface. It is a region having a distance within 1/3 of the width of the land portion 40 (the length in the tire width direction W) in the tire width direction W with the point as the center.

  For example, the length W3 in the tire width direction W between the tire width direction position A and the tire equator line CL may be about 1/4 of the length W1 of the tread portion 10 in the tire width direction W.

  In the tread portion 10 of the tire 1 according to the present embodiment, in the region A2 on the end side in the tire width direction W from the end portion of the small crossing belt layer 13, the tire equator line CL is more than the end portion of the small crossing belt layer 13. The angle formed by the cords constituting each belt layer and the tire circumferential direction L is larger than that of the side region A1.

  That is, in the tread portion 10 of the tire 1, in the region A2 on the end side in the tire width direction W with respect to the end portion of the small crossing belt layer 13, the tire equatorial line CL side with respect to the end portion of the small crossing belt layer 13. The belt tension is smaller than that in the region A1.

  As a result, in the tread portion 10 of the tire 1, the region A2 on the end side in the tire width direction W from the end portion of the small crossing belt layer 13 is closer to the tire equator line CL side than the end portion of the small crossing belt layer 13. Compared to the region A1, the length of the region A1 in the tire circumferential direction L is longer than the length of the region A2 in the tire circumferential direction L.

  Therefore, when the tire 1 rotates, a force in the tire rotation direction R (driving force) is generated in the region A1, and a force (braking force) in the opposite direction to the tire rotation direction R is generated in the region A2. A shearing force is generated in the vicinity of the boundary between the region A1 and the region A2 (that is, the region near the end of the small crossing belt layer 13).

  Here, in the tire 1 according to the present embodiment, by providing the above-described bent portions 50A / 50B, as shown in FIG. 4, the land portion 40 is compared with a case in which the bent portions 50A / 50B are not provided. The force (braking force) F1 in the direction opposite to the tire rotation direction R generated in is reduced.

  As a result, the shear force generated near the boundary between the regions A1 and A2 (that is, the region near the end of the small crossing belt layer 13) can be reduced.

  Further, in the tire 1 according to the present embodiment, by providing the above-described bent portion 50A / 50B, as shown in FIG. 4, in the land portion 40, as compared with the case where the bent portion 50A / 50B is not provided. The generated force (driving force) F2 in the tire rotation direction R is increased.

  As a result, the shear force generated near the boundary between the regions A1 and A2 (that is, the region near the end of the small crossing belt layer 13) can be reduced.

  In the tire 1 according to the present embodiment, a narrow groove (sipe) or various grooves may be further provided according to required performance.

(Modification 1)
Hereinafter, with reference to FIG. 5, the tire 1 according to the first modification of the present invention will be described focusing on the difference from the tire according to the first embodiment.

  As shown in FIG. 5, in the tire 1 according to the first modification, the widthwise groove 20 bent by the bent portions 50A / 50B may be configured to be curved in a curved shape.

  According to the tire 1 according to the first modification example, in the peripheral region of the apex 50C of the bent portions 50A / 50B, the inclination angle of the widthwise groove 20 with respect to the tire width direction W is configured to be large. The driving effect in the peripheral region of the apex 50C of the portion 50A / 50B is increased, and the inclination angle of the widthwise groove 20 with respect to the tire width direction W is decreased in the region other than the peripheral region of the apex 50C. The braking effect can be dispersed in a region other than the peripheral region of the vertex 50C.

(Modification 2)
Hereinafter, the tire 1 according to the second modification of the present invention will be described with reference to FIG. 6 while focusing on the differences from the tire according to the first embodiment.

  In the tire 1 according to the second modified example, the widthwise groove 20 has at least two bent portions 51A1 / 51A2 (or 51B1 / 51B2) on at least one side of the tire equator line CL.

  Here, the width direction groove 20 is a flat portion 60A (or alternatively, formed so as to be substantially parallel to the tire width direction W between the two bent portions 51A1 / 51 (or 51B1 / 51B2). 60B).

  According to the tire 1 according to the first modification example, since the flat portion 60A (or 60B) is provided between the two bent portions 51A1 / 51 (or 51B1 / 51B2), the flat portion 60A / 60B Driving force is generated as a whole.

  In the actual tire 1, it is assumed that the driving force needs to be generated within a certain range. In such a case, the provision of the flat portion 60 </ b> A / 60 </ b> B is the performance of the tire 1. It leads to improvement.

(Modification 3)
Hereinafter, with reference to FIG. 7, the tire 1 according to Modification 3 of the present invention will be described by focusing on differences from the tire according to Embodiment 1 described above.

  As shown in FIG. 7, in the tire 1 according to the third modification of the present invention, the width direction groove 20 is configured not to be continuous on the tire equator line CL.

  That is, in the tire 1 according to the third modification of the present invention, the pitches P1 / P2 of the land portions 40 disposed on both sides of the tire equator line CL may be configured to deviate.

  For example, the deviation amount Δ of the pitch P1 / P2 may be 20% or less of the length L1 of each land portion 40 in the tire circumferential direction L.

  According to the tire 1 according to the third modification of the present invention, the rigidity in the tire circumferential direction L can be made uniform.

(Modification 4)
Hereinafter, with reference to FIG. 8, the tire 1 according to Modification 4 of the present invention will be described by focusing on differences from the tire according to Embodiment 1 described above.

  As shown in FIG. 8, from the viewpoint of formability during vulcanization, in the tire 1 according to the modified example 4 of the present invention, the circumferential narrow groove 70 is provided in the land portion 40 along the tire circumferential direction L. It may be done.

  For example, the circumferential narrow groove 70 may be formed in a region where the distance from the tire equator line CL to the outer side in the tire width direction is 0.55 L to 0.70 L in each land portion 40. Here, “L” is the length of each land portion 40 in the tire width direction.

  The circumferential narrow groove 70 may be configured to intersect the vertex 50C of the bent portions 50A / 50C (or the peripheral region of the vertex 50C) and extend in the tire circumferential direction L.

(Modification 5)
Hereinafter, with reference to FIG. 9, the tire 1 according to the fifth modification of the present invention will be described by focusing on the differences from the tire according to the first embodiment.

  As shown in FIG. 9, in the tire 1 according to the modified example 5 of the present invention, the land portions 40A / 40B arranged on both sides of the tire equator line CL may be configured to have different shapes. .

  For example, as shown in FIG. 9, in the tire 1 according to the modified example 5 of the present invention, the width (length in the tire width direction W) of the land portions 40A / 40B disposed on both sides of the tire equator line CL is It may be configured differently.

  As shown in FIG. 9, the ratio of the width of the land portion 40A / 40B disposed on one side of the tire equator line CL and the width of each land portion 40 disposed on the other side of the tire equator line CL is 6: It may be in the range of 4-9: 1.

  That is, in the tire 1 according to the fifth modification of the present invention, the pattern of the left land portion 40A and the pattern of the right land portion 40BA are not line symmetric with respect to the tire equator line.

  The tire 1 according to the fifth modification of the present invention is effective when the input of the ground contact surface of the tire 1 is different in the tire width direction W when the camber angle is given.

(Modification 6)
Hereinafter, with reference to FIG. 10, the tire 1 according to Modification 6 of the present invention will be described by focusing on differences from the tire according to Embodiment 1 described above.

  In the tire 1 according to Modification 6 of the present invention, the widthwise groove 20 has two bent portions 51A1 / 51A2 on the left side of the tire equator line CL, and two bent portions 51B1 on the right side of the tire equator line CL. / 51B2.

  Here, the width direction groove 20 is a flat portion 60A (or alternatively, formed so as to be substantially parallel to the tire width direction W between the two bent portions 51A1 / 51 (or 51B1 / 51B2). 60B).

  Further, in the tire 1 according to the modified example 6 of the present invention, on the left side of the tire equator line CL, a circumferential narrow groove 70A that intersects the flat portion 60A and extends in the tire circumferential direction L is provided, and the tire equator line CL On the right side, there is provided a circumferential narrow groove 70B that intersects the flat portion 60B and extends in the tire circumferential direction L.

  Next, in order to clarify the effect of the present invention, results of tests performed using tires according to Comparative Example 1 and Example 1 will be described. In addition, this invention is not limited at all by these examples.

  In this experiment, the radial tire shown in FIG. 3 having the widthwise grooves 20 having the bent portions 50A / 50B is used as the tire according to Example 1, and the bent portions 50A / 50B are used as the tire according to Comparative Example 1. A radial tire having no width direction groove 20 was used.

  In this test, the size of all radial tires was “185 / 70R14”. Further, in this test, the position A in the tire width direction shown in FIG. 1 was measured using a measuring device described in JP-A-7-63658, with a speed of 50 mm / s, a load of 3.5 kN, and an internal pressure of 0.19 MPa. The wear energy was measured.

  Here, the width of the rim used in this test was 5-J × 14 (standard size specified by JATMA).

  According to the measurement results, the tire according to Example 1 having the configuration of the present invention has a wear energy reduced by about 20% as compared with the tire according to Comparative Example 1.

  Although the present invention has been described in detail using the above-described embodiments, it is obvious to those skilled in the art that the present invention is not limited to the embodiments described in this specification. The present invention can be implemented as modified and changed modes without departing from the spirit and scope of the present invention defined by the description of the scope of claims. Therefore, the description of the present specification is for illustrative purposes and does not have any limiting meaning to the present invention.

DESCRIPTION OF SYMBOLS 1 ... Tire, 10 ... Tread part, 11 ... Protection belt layer, 11A, 11B ... Protection belt, 12 ... Main crossing belt layer, 12A, 12B ... Main crossing belt, 13 ... Small crossing belt layer, 13A, 13B ... Small crossing Belt 20, width direction groove 30, circumferential groove 40, land portion 50 A, 50 B, 51 A 1, 51 A 2, 51 B 1, 51 B 2 bending portion 60 A 60 B flat portion 70 70 A 70 B thin circumferential direction groove

Claims (3)

In the tread portion, a circumferential groove extending in the tire circumferential direction or an end portion of the tread portion in the tire width direction and a length in the tire width direction are 30% or more of a length of the tread portion in the tire width direction. A tire having a plurality of land portions partitioned by a widthwise groove extending in the tire width direction configured as described above,
The widthwise groove has a bent portion configured to bend in at least one side of the tire equator line in a direction opposite to at least one tire rotation direction,
It has a plurality of belt layers,
At least one of the bent portions is provided in the vicinity of the position in the tire width direction corresponding to the end portion of the belt layer having the smallest angle between the cord constituting the belt layer and the tire circumferential direction ,
In the plan view of the tread portion, the widthwise groove is curved in a curved shape so that an inclination angle of the widthwise groove with respect to the tire width direction increases as the apex of the bent portion increases. . The width direction groove has at least two bent portions on at least one side of the tire equator line,
The tire according to claim 1, wherein the width direction groove has a flat portion formed between the two bent portions so as to be substantially parallel to the tire width direction.   The tire according to claim 2, further comprising a circumferential narrow groove that intersects the flat portion and extends in the tire circumferential direction.

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