JP4992328B2 - tire - Google Patents

Description

  The present invention relates to a tire, and more particularly to a tire in which a plurality of protrusions are formed on a tread surface in a land portion of a tread portion.

  Conventionally, in tires, particularly studless tires, in order to improve the driving force against the road surface or the braking force against the road surface in the initial use of the tire, for example, as shown in Patent Document 1, the surface of the dread that forms the tread portion is uneven. Has been proposed. In the tires in these Patent Documents, the edge increases due to the formed irregularities, and the edge effect of the increased edge can improve the driving force on the road surface or the braking force on the road surface in the initial use of the tire. is there.

  In the tire as shown in Patent Document 1, the unevenness is formed in the tire width direction, which is a direction orthogonal to the tire circumferential direction. Therefore, the edge is formed extending in the tire width direction. The edge effect at the edge is most exhibited in the direction orthogonal to the direction in which the outer peripheral surface is formed, that is, in the normal direction. That is, in the tire as shown in Patent Document 1, the edge effect is most exhibited in the tire rotation direction that is the tire circumferential direction.

Japanese Patent No. 3017677

  However, in a tire mounted on a vehicle together with a rim that is assembled, the tire rotation direction and the vehicle traveling direction are different, and the tire may have a slip angle. When the tire has a slip angle, the edge effect due to the edge is reduced as compared with the case where the vehicle is traveling straight. This is because when the vehicle is traveling straight, the slip angle is 0 degree and the relative movement direction of the road surface with respect to the tire is parallel to the normal direction of the edge. This is because the normal direction is not parallel to the edge, and the edge effect by the edge cannot be exhibited most. This makes it difficult to improve the driving force on the road surface or the braking force on the road surface during cornering.

  This invention is made in view of the above, Comprising: It aims at providing the tire which can fully exhibit the edge effect by an edge, even if a tire has a slip angle.

In order to solve the above-described problems and achieve the object, in the tire according to the present invention, in a tire having a tread portion including a plurality of groove portions and a plurality of land portions partitioned by the groove portions, the land The tread surface in the portion is formed with a plurality of protrusions whose protrusions with respect to the tread surface increase in one direction, and each protrusion has an edge formed between the inclined surface and the outer peripheral surface. It protrudes in one direction, the edge is an arc, elliptical arc, characterized by at least any one Tsudea Rukoto three or more straight lines.

  According to this invention, the plurality of projecting portions formed on each land portion are formed so that the edges project in one direction. That is, the edge has a plurality of normal directions. As a result, the tire has a normal direction other than the same normal direction as the tire circumferential direction as compared with a conventional tire having one normal direction of the edge and the normal direction being the tire circumferential direction. Even if a slip angle is provided, the relative movement direction of the road surface with respect to the tire is parallel to any one of a plurality of normal directions of the edge, and the edge effect by the edge can be sufficiently exhibited.

  In the tire, it is preferable that the protruding portion is formed continuously in at least one of the one direction or the orthogonal direction orthogonal to the one direction.

  Moreover, in the said tire, it is preferable that the said protrusion part adjacent in the said orthogonal direction is mutually connected at least one end among the both ends of the said edge.

  Moreover, in the tire, it is preferable that at least one of the ends of the edge is connected to the outer peripheral surface of the protruding portion adjacent in the one direction.

  In the tire, the one direction is preferably any one of the tire circumferential directions.

  Moreover, in the said tire, the said one direction in the center side protrusion part formed in the said land part arrange | positioned at a tire center part is any one direction in a tire circumferential direction, and is arrange | positioned at a tire shoulder part. It is preferable that the one direction in the shoulder side protrusion formed in the land portion is different from the one direction in the center side protrusion.

  In the tire, the one direction in the shoulder side protrusion is a direction from the tire shoulder to the tire center, and the one direction in the shoulder side protrusion and the center side protrusion The angle formed with the one direction is preferably 45 degrees or less.

  Moreover, in the said tire, it is preferable that the maximum protrusion amount of each said protrusion part changes with the said land parts.

  Further, in the tire, the maximum protrusion amount includes, among the land portions, an inner protrusion portion formed on the land portion disposed on the inner side when the vehicle is mounted and the land portion disposed on the outer side when the vehicle is mounted. It is preferable that the outer protrusions formed on the outer surface are different.

  Moreover, in the said tire, it is preferable that the maximum length of the both ends in the said one direction of the inclined surface of each said protrusion part changes with the said land parts.

  Further, in the tire, the maximum length includes an inner projecting portion formed on the land portion disposed on the inner side when the vehicle is mounted, and the land portion disposed on the outer side when the vehicle is mounted. It is preferable that the outer protrusions formed on the outer surface are different.

  In the tire, the maximum protrusion amount of each protrusion is preferably 0.1 mm or more and 2.0 mm or less.

  Moreover, in the said tire, it is preferable that the maximum length of the both ends in the said one direction of the inclined surface of each said protrusion part shall be 0.3 mm or more and 10 mm or less.

  In the tire according to the present invention, since the edge of each protruding portion has a plurality of normal directions, the edge effect by the outer peripheral surface can be sufficiently exhibited even if the tire has a slip angle.

  Hereinafter, the present invention will be described in detail with reference to the drawings. The present invention is not limited to the following examples. In addition, constituent elements in the following embodiments include those that can be easily assumed by those skilled in the art or those that are substantially the same. Here, the tire is mounted on a vehicle, but includes not only a tire mounted on a passenger car or the like but also a heavy load tire mounted on a truck, a bus or the like. Further, in the following embodiment, a tire whose land portion is composed only of blocks will be described, but the present invention is not limited thereto, and a tire whose land portion is composed of blocks and ribs, You may use for the tire from which the land part was comprised only with the rib.

  FIG. 1 is a diagram showing a configuration example of a tire according to the present invention. FIG. 2 is a diagram illustrating a configuration example of each block. FIG. 3 is a cross-sectional view taken along the line AA of FIG. FIG. 4 is an enlarged view of part B of FIG. In addition, the protrusion part in each figure is displayed larger than actual with respect to the land part.

  As shown in FIG. 1, a tire 1 according to the present invention has a tread portion 2. The tread portion 2 includes a plurality of groove portions and a plurality of land portions defined by the groove portions. The plurality of groove portions include a plurality of circumferential grooves 21 that are continuous in the tire circumferential direction and a plurality of lug grooves 22 that are continuous in the tire width direction and at least one end of which communicates with the circumferential groove 21. The plurality of land portions include a plurality of center-side blocks 23 defined by the circumferential grooves 21 and lug grooves 22 in the tire center portion, and a plurality of shoulder sides defined by the circumferential grooves 21 and lug grooves 22 in the tire shoulder portion. Block 24.

  As shown in FIGS. 1 to 4, a plurality of protruding portions 3 are formed in each land portion, that is, the center side block 23 and the shoulder side block 24. Each protrusion 3 protrudes outward in the tire radial direction. Moreover, the protrusion amount with respect to the tread surface 2a which is the surface of the tread part 2 of each protrusion part 3 is formed to increase toward the tire rotation direction which is one of the tire circumferential directions. Thereby, each protrusion part 3 has the inclined surface 31 which inclines gently toward the tire radial direction outer side in the tire rotation direction, and the outer peripheral surface 32 which inclines toward the tire radial direction inner side in the tire rotational direction. It is comprised by. Each protrusion 3 has an edge S formed between the inclined surface 31 and the outer peripheral surface 32. Each protrusion 3 protrudes in the tire rotation direction in which the edge S is one direction. In this embodiment, each protrusion 3 is formed so as to form an arc protruding in the tire rotation direction.

  Here, as shown in FIG. 3, it is preferable that the maximum protrusion amount H of each protrusion part 3 is 0.1 mm or more and 2.0 mm or less. Furthermore, it is preferable that it is 0.1 mm or more and 1.0 mm or less. The maximum protrusion amount H is set to 0.1 mm or more. When the protrusion amount H is less than 0.1 mm, it is difficult to process the concave portion in which the protrusion 3 is transferred to the tire molding die for forming the tire 1. Because. The reason why the maximum protrusion amount H is set to 2.0 mm or less is that uneven wear may occur when the maximum protrusion amount H exceeds 2.0 mm.

  Moreover, it is preferable that the maximum length W of the both ends in one direction of each protrusion part 3 is 0.3 mm or more and 10 mm or less. Furthermore, it is preferable that it is 2 mm or more and 5 mm or less. If the maximum length W is set to 0.2 mm or more, if it is less than 0.2 mm, it becomes difficult to process the concave portion obtained by transferring the protruding portion 3 to the tire molding die for molding the tire 1. Because. Moreover, the reason why the maximum length W is set to 10 mm or less is that the edge effect may be lowered if it exceeds 10 mm. In this embodiment, the maximum protrusion amount H and the maximum length W of the protrusions 3 formed in the land portions, that is, the center side block 23 and the shoulder side block 24, are substantially the same.

  As shown in FIG. 1 and FIG. 2, the protrusion 3 is continuous with each center side block 23 and each shoulder side block 24 in the tire rotation direction that is one direction and the tire width direction that is orthogonal to the one direction. Is formed. Of the protrusions 3 formed in the center side blocks 23 and the shoulder side blocks 24, the protrusions 3 adjacent in the tire width direction are connected to each other at least one of the ends S1 and S2 of the edge S. ing. In this embodiment, one end S1 of the edge S of each protrusion 3 is connected to the other end S2 of the edge S of the protrusion 3 adjacent in the tire width direction, and the other end S2 of the edge S of each protrusion 3 is the tire width. It connects with one end S1 of the edge S of the protrusion part 3 adjacent to a direction. Of the protrusions 3 formed on the center side blocks 23 and the shoulder side blocks 24, the protrusions 3 adjacent to each other in the tire rotation direction have at least one of the ends S 1 and S 2 of the edge S on the outer peripheral surface 32. One end is connected. In this embodiment, one end S1 of the edge S of the protruding portion 3 adjacent in the tire rotation direction is connected to the substantially central portion in the tire width direction of the outer peripheral surface 32 of each protruding portion 3, and the one end S1 is connected. The other end S2 of the edge S of the protruding portion 3 adjacent to the protruding portion 3 in the tire width direction is connected. In other words, the plurality of protrusions 3 formed in each center side block 23 and each shoulder side block 24 are such that each protrusion 3 is continuous in the tire width direction and the tire of each protrusion 3 in the tire rotation direction. The pitch in the width direction is continuously shifted by a half pitch. In this embodiment, the arc of the edge S of each protrusion 3 is continuous in the tire width direction and is shifted by a radius in the tire rotation direction. Thereby, each center side block 23 and each shoulder side block 24 are formed with a scale-like pattern that is visually recognized like a fish scale by the plurality of protrusions 3 formed thereon.

  As shown in FIG. 4, the edge S of each projecting portion 3 has a plurality of normal directions C because each edge S is an arc projecting in one direction of tire rotation. As described above, the edge effect by the edge S is most exhibited in the normal direction. Therefore, the edge S of each protrusion 3 can exhibit an edge effect in a wide range. Here, even if the tire 1 has a slip angle and the relative movement direction of the road surface with respect to the tire 1 is different from the relative movement direction D that is parallel to the tire rotation direction, the relative movement direction when the tire 1 has a slip angle. E is parallel to one of the plurality of normal directions C of the edge S. Thereby, even if a tire has a slip angle, the edge effect by the edge S of each protrusion part 3 can fully be exhibited. Therefore, the tire 1 having the center side block 23 and the shoulder side block 24 in which the protruding portion 3 is formed can improve at least one of the driving force on the road surface and the braking force on the road surface in the initial use of the tire. In particular, the driving force with respect to the road surface or the braking force with respect to the road surface can be improved in the initial use of the tire during cornering.

  Further, the center side block 23 and the shoulder side block 24 have an inclined surface 31 that is gently inclined in the tire rotation direction and outward in the tire radial direction, and abruptly inclined in the tire rotation direction and inward in the tire radial direction. The outer peripheral surface 32 is formed continuously in the tire rotation direction. Therefore, when the tire 1 comes into contact with the road surface, the inclined surface 31 and the outer peripheral surface 32 can easily come into contact with the road surface, and the edge effect of the edge S can be further improved. Further, as described above, the center side block 23 and the shoulder side block 24 are formed with the inclined surface 31 and the outer peripheral surface 32 which are continuously formed in the tire rotation direction, so that the snow drainage can be improved. it can.

  In the above embodiment, the edge S is a circular arc, but the present invention is not limited to this. 5 and 6 are diagrams showing another configuration example of each block of the tire according to the present invention. For example, as shown in FIG. 5, the edges S of the protrusions 4 formed in the center side block 23 and the shoulder side block 24 may be constituted by three straight lines. The edge S of each protrusion 4 has a total of three normal directions C in both the tire rotation direction and the tire width direction. In the case where the edge S is constituted by a plurality of straight lines, the edge S is not limited to the three straight lines shown in FIG.

  For example, as shown in FIG. 6, the edges S of the protrusions 5 formed in the center block 23 and the shoulder block 24 may be elliptical arcs. Each protrusion 5 has a larger radius of curvature in the vicinity of the tire width direction, which is the orthogonal direction, in the edge S than in the vicinity of the tire rotation direction, which is one direction. Accordingly, the edge S of each protrusion 5 has more normal directions C in the vicinity of the tire width direction than in the vicinity of the tire rotation direction. Thereby, the edge S of each protrusion part 5 can further exhibit the edge effect when the tire 1 has a slip angle as compared with the edge S of each protrusion part 3.

  Moreover, in the said Example, each protrusion part 3 formed in the center side block 23 and the shoulder side block 24 is made to increase toward the tire rotation direction where the protrusion amount with respect to the tread surface 2a is one direction, and it is an inclined surface. Although the edge formed between 31 and the outer peripheral surface 32 is made to protrude in this tire rotation direction, this invention is not limited to this. 7 and 8 are diagrams showing another example of the configuration of the tire 1 according to the present invention.

  For example, as shown in FIG. 7, the center-side protruding portion 6 formed in the center-side block 23 that is a land portion disposed in the tire center portion has one direction on the center side as the tire rotation direction, The shoulder side protruding portion 7 formed on the shoulder side block 24 that is a land portion arranged in the tire shoulder portion may have one direction on the shoulder side different from the tire rotation direction. Here, the one direction on the shoulder side is a direction from the tire shoulder portion toward the tire center portion, and the angle θ formed with the tire rotation direction which is the one direction on the center side is preferably 45 degrees or less. Further, θ is preferably less than 30 degrees. The reason why the angle formed is 45 degrees is that if the angle exceeds 45 degrees, the edge effect during straight travel may be reduced.

  As shown in FIG. 4, the edge S of each protrusion 3 can exhibit the edge effect most when the relative movement direction of the road surface with respect to the tire 1 is a relative movement direction D opposite to the tire rotation direction. That is, the edge S of each protrusion 3 exhibits the edge effect most when the one direction and the relative movement direction face each other. This is because the edge S can receive the force from the relative movement direction or one direction in the widest range when the one direction and the relative movement direction are parallel to each other.

  Therefore, as shown in FIG. 7, the edge S of the center side protruding portion 6 has the edge effect most exhibited when the tire rotation direction and the relative movement direction are parallel, that is, when the tire 1 has no slip angle. The edge S of the protruding portion 7 has a different edge direction than the edge S of the center-side protruding portion 6 when the tire rotation direction and the relative movement direction are different, that is, when the tire 1 has a slip angle. As a result, the driving force with respect to the road surface or the braking force with respect to the road surface can be further improved in the initial use of the tire during cornering.

  Further, for example, as shown in FIG. 8, the center side one direction in the center side protruding portion 8 is set as the tire rotating direction, the shoulder side one direction in the shoulder side protruding portion 9 is made different from the tire rotating direction, and the maximum length W is set. The center side protrusion 8 and the shoulder side protrusion 9 may be different. Here, the maximum length W of the center side protrusion 8 is made larger than that of the shoulder side protrusion 9. That is, each center side protrusion 8 is made larger than each shoulder side protrusion 9. Note that not only the maximum length W but also the maximum protrusion amount H may be different between the center side protrusion 8 and the shoulder side protrusion 9. Further, only the maximum protruding amount H may be different between the center side protruding portion 8 and the shoulder side protruding portion 9.

  Further, at least one of the maximum protrusion amount H and the maximum length W is different between the center-side protrusion 8 and the shoulder-side protrusion 9, and the land portion disposed on the inner side when the tire 1 is mounted on the vehicle. (For example, in the tire 1 shown in FIG. 3, the center-side block 23 and the right shoulder-side block 24 disposed on the right side) and the land disposed on the outer side when the tire 1 is mounted on the vehicle. For example, in the tire 1 shown in the figure, the outer projecting portion formed in the center side block 23 and the left shoulder side block 24 arranged on the left side may be different. For example, at least one of the maximum protrusion amount H or the maximum length W of the inner protrusion is made larger than that of the outer protrusion. That is, the outer protrusion is made smaller than the inner protrusion. As a result, it is possible to improve the driving force with respect to the road surface or the braking force with respect to the road surface during cornering at the initial stage of use of the tire by the outer protruding portion, and it is possible to improve the snow drainage by the inner protruding portion.

  Below, the implementation result of the running test with the conventional example and the tire 1 concerning this invention is demonstrated. Here, each tire used for this running test has a common tire size of 195 / 65R15. In addition, each tire of the above size was assembled on an appropriate rim (15 × 6 1/2 JJ) prescribed by JATMA, the air pressure was 200 kPa, and the vehicle was mounted on a rear-wheel drive vehicle with a displacement of 2000 CC.

  Here, the groove depth (mm) in Table 1 below indicates the depth of this groove in a tire (conventional examples 1 and 2) in which continuous grooves are formed as irregularities on the tread surface. The maximum protrusion amount H (mm) indicates the maximum protrusion amount that protrudes outward in the tire radial direction of the protrusion portion of the tire according to the present invention. The maximum length W (mm) indicates the maximum length at both ends in one direction of the inclined surface of the protruding portion of the tire according to the present invention. The groove width (mm) indicates the width of the groove in a tire (conventional examples 1 and 2) in which continuous grooves are formed as irregularities on the tread surface. The groove interval (mm) indicates the groove pitch in a tire (conventional examples 1 and 2) in which continuous grooves are formed on the tread surface as irregularities. The edge shape indicates the shape of the edge of the protruding portion of the tire according to the present invention. The groove forming direction indicates a direction in which a groove extends in a tire (conventional examples 1 and 2) in which continuous grooves are formed as irregularities on the tread surface. The one direction indicates a direction in which the protruding amount of the protruding portion of the tire according to the present invention with respect to the tread surface increases.

  The on-ice braking performance is an index evaluation of a braking distance from an initial speed of 40 km / h on an on-ice road surface. Steering stability is an index evaluation of the average value when running on a city snow pressure reproduction road surface by a plurality of panelists. The braking performance on ice and the handling stability are better when “Conventional Example 2” is set to 100 and the numerical value is larger.

  Here, “Conventional Example 1” indicates a tire in which grooves are continuously formed in the tire rotation direction as irregularities on the tread surface, and the groove forming direction is the tire width direction. “Conventional example 2” indicates a tire in which grooves are continuously formed in the tire rotation direction as irregularities on the tread surface, and the groove formation direction is inclined by 30 degrees with respect to the tire rotation direction.

  “Invention 1” indicates a tire in which the protrusions have the same size, the edge shape is three straight lines, and one direction at the protrusion is the tire rotation direction (see FIG. 5). “Invention 2” refers to a tire in which the protrusions have the same size, the edge shape is an arc, and one direction in the protrusion is the tire rotation direction (see FIGS. 1 to 4). In “Invention 3”, the center side protrusion and the shoulder side protrusion are all the same size, the edge shape is an arc, and one direction (center side one direction) in the center side protrusion is the tire rotation direction. There is a tire in which one direction (one direction on the shoulder side) in the shoulder side protruding portion is inclined by 30 degrees with respect to the tire rotation direction (see FIG. 7). In the “present invention 4”, the center side protruding portion is larger than the shoulder side protruding portion, the shape of the edge is a circular arc, one direction (center side one direction) in the center side protruding portion is the tire rotation direction, and the shoulder side The tire in which one direction (one direction on the shoulder side) in the protruding portion is inclined by 30 degrees with respect to the tire rotation direction (see FIG. 8).

  As is apparent from Table 1, the tires shown in “Invention 1” to “Invention 4” have braking properties on the ice and steering stability compared to the tires shown in “Conventional Example 1” and “Conventional Example 2”. Improved. That is, the driving force on the road surface and the braking force on the road surface can be improved in the initial use of the tire.

  Further, in the tires shown in “Invention 2” to “Invention 4” in which the shape of the edge is an arc, since the normal direction of the edge is increased, the steering stability can be further improved.

  In addition, the tire shown in “present invention 3” and “present invention 4” in which one direction in the center side protruding portion is the tire rotating direction and one direction in the shoulder side protruding portion is inclined by 30 degrees with respect to the tire rotating direction. Then, since the edge effect by the edge when the tire has a slip angle is exhibited, the steering stability can be further improved.

  Further, in the tire shown in “Invention 4” in which the size of the center side protrusion and the shoulder side protrusion are all the same, the braking performance on ice and the steering stability can be further improved.

  As described above, the tire according to the present invention is useful for a tire having irregularities formed on the tread surface, and is particularly suitable for exhibiting the edge effect due to the edge even when the tire has a slip angle. .

It is a figure which shows the structural example of the tire concerning this invention. It is a figure which shows the structural example of each block of the tire concerning this invention. It is AA sectional drawing of FIG. FIG. 3 is an enlarged view of part B of FIG. 2. It is a figure which shows the other structural example of each block of the tire concerning this invention. It is a figure which shows the other structural example of each block of the tire concerning this invention. It is a figure which shows the other structural example of the tire concerning this invention. It is a figure which shows the other structural example of the tire concerning this invention.

Explanation of symbols

1 Tire 2 Tread 2a Tread surface 21 Circumferential groove (groove)
22 Lug groove (groove)
23 Center side block 24 Shoulder side block 3 Protruding part 31 Inclined surface 32 Outer peripheral surface 4,5 Protruding part 6,8 Center side projecting part 7,9 Shoulder side projecting part S Edge

Claims (13)

In a tire having a tread portion constituted by a plurality of groove portions and a plurality of land portions partitioned by the groove portions,
The tread surface in the land portion is formed with a plurality of protrusions whose protrusion amount with respect to the tread surface increases in one direction,
Wherein each projection is the edge formed between the inclined surface and the outer circumferential surface protrudes in the one direction,
The tire is characterized in that the edge is at least one of an arc, an elliptical arc, and three or more straight lines .   2. The tire according to claim 1, wherein the protruding portion is formed continuously in at least one of the one direction or an orthogonal direction orthogonal to the one direction.   The tire according to claim 2, wherein at least one of the ends of the edges of the protrusions adjacent in the orthogonal direction is connected to each other.   The tire according to any one of claims 1 to 3, wherein at least one of the two ends of the edge is connected to the outer peripheral surface of the protruding portion adjacent in the one direction. . The tire according to any one of claims 1 to 4 , wherein the one direction is one of tire circumferential directions. The one direction in the center side protruding portion formed in the land portion arranged in the tire center portion is any one direction of the tire circumferential direction,
The said one direction in the shoulder side protrusion part formed in the said land part arrange | positioned at a tire shoulder part differs from the said one direction in the said center side protrusion part, The any one of Claims 1-4 characterized by the above-mentioned. Tire described in. The one direction in the shoulder side protruding portion is a direction from the tire shoulder portion toward the tire center portion,
The tire according to claim 6 , wherein an angle formed by the one direction in the shoulder side protrusion and the one direction in the center side protrusion is 45 degrees or less. The tire according to the maximum amount of projection of the projecting portion is any one of claims 1-7, characterized in different by the land portion. The maximum projecting amount includes an inner projecting portion formed on the land portion disposed on the inner side when the vehicle is mounted and an outer projecting portion formed on the land portion disposed on the outer side when the vehicle is mounted. The tire according to claim 8 , wherein the tire differs. The tire according to any one of claims 1 to 9 , wherein a maximum length of both ends in the one direction of the inclined surface of each protrusion is different depending on the land portion. Among the land portions, the maximum length is an inner projecting portion formed on the land portion disposed on the inner side when the vehicle is mounted, and an outer projecting portion formed on the land portion disposed on the outer side when the vehicle is mounted. The tire according to claim 10 , wherein the tire differs. The tire according to any one of claims 1 to 11 , wherein the maximum protrusion amount of each protrusion is 0.1 mm or more and 2.0 mm or less. The tire according to any one of claims 1 to 12 , wherein a maximum length of both ends in the one direction of the inclined surface of each protrusion is set to be 0.3 mm or more and 10 mm or less.

Images