JP4710451B2 - Pneumatic tire - Google Patents

Description

  The present invention relates to a pneumatic tire, and more particularly to a pneumatic tire that facilitates determination of a heel and toe wear state of a tire.

  The pneumatic tire gradually wears due to contact friction with the road surface as it travels. In particular, in heavy-duty tires provided with a block pattern or a lug pattern, uneven wear of heel and toe tends to occur on the block or lug. Such uneven wear can be inspected regularly and the tire life can be extended by appropriately rotating the tire position before the uneven wear does not progress to a certain limit. However, it is very difficult for many drivers to determine the timing of tire rotation by accurately judging uneven wear.

  FIG. 6 is a partially enlarged view of a block in which heel and toe wear occurs in a heavy load tire having a block pattern as seen from the side of the tire, and the block kicking side is more unevenly worn than the stepping side with respect to the rotation direction T. Indicates the state.

  Such heel-and-toe wear is measured by measuring the height of the block in the tire circumferential direction, and is determined by the dimensional difference. It is a very difficult task to accurately determine when.

  In order to solve such a problem, Patent Document 1 proposes that a linear wear detector is provided in multiple stages on a groove wall surface of a block formed in a tread portion. However, since this linear wear detector is formed parallel to the tread surface, in order to grasp the degree of heel and toe wear, after reading the scales before and after the block, various tread patterns, block widths, etc. It was necessary to make a judgment while considering the factors.

Therefore, since a general driver needs skill to accurately grasp the progress of heel and toe wear, it cannot always be said that the tire rotation timing can be easily and accurately determined.
JP 2000-289414 A

  An object of the present invention is to provide a pneumatic tire in which a progress state of heel and toe wear in a block pattern or a lug pattern can be easily grasped.

  The pneumatic tire of the present invention that achieves the above object is a pneumatic tire provided such that at least a land portion made of a block or a lug is connected to a shoulder portion of a tread, and the tread surface is tangential to an outer surface of the land portion. Alternatingly in the tire circumferential direction, land portions formed with multi-stage wear display lines having an inclination angle of 0.5 ° to 10 ° and land portions formed with multi-stage wear display lines whose inclination directions are opposite to each other are inclined. It is characterized by providing in.

  In the pneumatic tire of the present invention, the wear display lines provided in multiple stages on the outer surface of the land portion are inclined at an angle of 0.5 ° to 10 ° with respect to the tread surface, so that the wear surface on the tread surface displays the wear display. The degree of progress of the heel and toe wear can be easily grasped simply by visually recognizing whether or not it is parallel to the line, and the timing of tire rotation can be accurately determined.

  In addition, because the land portions with the wear indicator lines inclined in opposite directions are alternately provided in the tire circumferential direction, the progress of the heel and toe wear of the tire is always easy regardless of the rotation direction of the tire attached to the vehicle. Can be judged.

  Hereinafter, the present invention will be described in detail with reference to embodiments shown in the drawings.

  FIG. 1 is a perspective view illustrating a part of a tread shoulder portion of a pneumatic tire according to the present invention, and FIG. 2 is an example of an enlarged view of one of the blocks as viewed from the side of the tire.

  In FIG. 1, a pneumatic tire 1 has a land portion 3 made of a block in a tread shoulder portion, and a plurality of wear display lines 4 are provided in multiple stages on the outer surface thereof. The plurality of wear display lines 4 are inclined at an angle of 0.5 ° to 10 ° with respect to the tangential direction of the tread surface 2 of the land portion 3. In addition, on the side surface of one land portion 3, the wear display line 4 has the same inclination direction, and the wear display line 4 has a reverse inclination direction in the land portion that is adjacent to the land portion 3 in the circumferential direction. Is forming. That is, the land portions where the wear indicator lines 4 are inclined in the same direction / the reverse direction are alternately arranged in the tire circumferential direction so that the inclination directions of the wear indicator lines 4 are the same in every other land portion. is doing.

  In FIG. 2, the wear display lines 4 are arranged at an inclination angle θ in the range of 0.5 ° to 10 ° with respect to the tangential direction of the tread surface 2. Here, the inclination angle θ is an angle formed by a plane in contact with a point located at the center in the circumferential direction of the tread surface 2 of the land portion 3 and the wear display line 4 on a plane including the outer surface of the land portion 3.

  In the pneumatic tire of the present invention, the wear display lines 4 provided in multiple stages on the outer surface of the land portion are inclined in advance at an angle of 0.5 ° to 10 ° with respect to the tangential direction of the tread surface 2. The degree of progress of heel and toe wear can be easily grasped simply by visually checking whether the inclination of the wear surface of the surface 2 is parallel to the inclination of the wear indication line 4, and the timing of tire rotation can be accurately determined. Judgment can be made.

  Furthermore, since the land portions in which the inclination directions of the wear indication lines 4 are opposite to each other are alternately provided in the tire circumferential direction, the progress of the heel and toe wear of the tire is always easy regardless of the rotation direction of the tire attached to the vehicle. Can be judged. Accordingly, even after the tire rotation is performed, the tire mounting position is changed to the left and right of the vehicle body, and the rotation direction of the tire is reversed, the land portions 3 adjacent to each other form the inclination directions of the wear display lines 4 in the opposite directions. Therefore, the progress of the heel and toe wear can be continuously determined using the reverse wear display line 4 as an index.

  In the present invention, the inclination angle θ of the wear display line 4 is 0.5 ° to 10 °, preferably 1 ° to 4 °. When the inclination angle θ is 0.5 ° or more, the wear display line 4 can be used as an index for visually confirming heel and toe wear when the pneumatic tire is a large-diameter tire. When the angle is 10 ° or less, the heel-and-toe wear progresses to a limit value in a tire having a small diameter, and can be used as an index indicating a warning to perform tire rotation. The inclination angle θ of the wear display line 4 can be appropriately selected depending on the tire size, application, tire pattern, and the like.

  In the present invention, the interval between the wear display lines 4 is preferably 0.5 to 3 mm, more preferably 1 to 2 mm. When the distance between the wear display lines 4 is 0.5 mm or more, the visibility of the wear display lines is improved. When the distance is 3 mm or less, the progress of heel and toe wear can be easily grasped.

  In the present invention, the form of the wear display line 4 is at least one line type selected from a solid line, a broken line, a dotted line, and a dot aggregate, and is formed by being distinguished according to the thickness (width), depth, or height of the line. It is preferable. Furthermore, the form of the wear display line 4 is preferably different from the form of other wear display lines 4 adjacent to each other. By making the forms of the wear display lines 4 adjacent to each other different, the visibility of the wear display lines 4 can be improved, which is preferable.

  3 and 4 are explanatory views showing another preferred embodiment of the pneumatic tire of the present invention, FIG. 3 is an example of a partially enlarged view of the side surface of the land portion 3, and FIG. It is an enlarged view of one land part side.

In FIG. 3, the wear display lines 4 are provided so that the adjacent wear display lines 4 have different inclination angles. More specifically, in FIG. 4, the inclination angles of the adjacent wear display lines 4 are set to θ ₁ , θ ₂ , and θ ₃ , and the inclination angles θ _{1 to} θ ₃ are all 0.5 ° to The angle is in the range of 10 °.

  Thus, on the side surface of the land portion 3, it is preferable that the inclination angle of the wear display line 4 is different from the inclination angle of the other wear display lines 4 adjacent to each other. By displaying the wear display lines 4 with different inclination angles on the side surface of one land portion 3, the progress of the heel and toe wear is easily visually recognized and grasped step by step from a light level to a heavy level. This is because it is possible to more accurately determine the timing of tire rotation.

For example, when the inclination of the tread surface 2 corresponds to the inclination of the wear display line 4 at the inclination angles θ _{1 to} θ ₂ , the heel and toe wear is in a state of caution and it is time to perform tire rotation. It is also possible to give meaning to each inclination angle, such as an index indicating a warning that heel and toe wear is close to the limit and should be immediately rotated when the inclination angle θ ₂ is exceeded and approaches θ _3. .

  In the present invention, the difference in the inclination angle θ between the wear display lines 4 adjacent to each other is preferably 0.5 ° to 2.5 °. By making the difference of the inclination angle θ within this range, the wear display lines 4 can be easily given meaning, and the adjacent wear display lines 4 in one land portion 3 are unlikely to cross each other and are more easily visible. preferable.

The setting of the inclination angles θ ₁ , θ ₂ , θ ₃ of the wear display line 4 can be appropriately selected depending on the tire size, application, tire pattern, and the like.

Further, the form of the wear display line 4 having the inclination angles θ ₁ , θ ₂ , θ ₃ can be changed depending on the line type (solid line, broken line, dotted line, and dot aggregate), line thickness (width), depth, or height. By distinguishing and forming, it becomes easy to distinguish the difference of inclination-angle (theta) ₁ , (theta) ₂ , (theta) ₃ , and since it becomes easy to recognize the meaning which each wear display line 4 has, it is preferable.

FIG. 5 is an explanatory view illustrating a partially enlarged view schematically illustrating a state in which heel and toe wear has occurred in the pneumatic tire having the land portion of FIG. 3. FIG. 6 is a schematic diagram in which uneven wear occurs around the circumferential direction of the land portion as shown in FIG. At this time, by observing the wear display lines 4 of the land portions 3 at both the left and right ends, it is easily recognized that the inclination of the tread surface 2 is substantially parallel to the inclination θ ₃ of the wear display line 4 shown by a thick solid line. It is done. Here, for example, if a thick solid wear indicator line 4 indicates that the progress of heel and toe wear is remarkable, it is easy and accurate to inform the driver that it is time to immediately perform tire rotation. Can be judged.

  Further, after the tire rotation is performed and the tire mounting position is changed to the left and right of the vehicle body and the tire rotation direction is reversed, the wear display line 4 formed on the land portion 3 in the center of FIG. It can be used as an index indicating the progress state of.

  With the pneumatic tire of the present invention, the state of heel and toe wear can be easily and accurately determined by simple visual recognition, the proper tire rotation time can be known, and an indicator of heel and toe wear can be obtained continuously after tire rotation. This makes it possible to extend the tire life.

  The pneumatic tire of the present invention is effective for grasping the progress of heel and toe wear in a block pattern or lug pattern, and is particularly useful for a heavy load tire or a studless tire.

It is explanatory drawing which illustrates a part of tread shoulder part of the pneumatic tire of this invention which illustrates a perspective view. It is explanatory drawing which shows an example of the enlarged view which looked at one of the blocks of FIG. 1 from the tire side surface. It is explanatory drawing which shows an example of the elements on larger scale of the land part side surface of the pneumatic tire of this invention. It is explanatory drawing which shows an example of the enlarged view which looked at one of the land parts of FIG. 3 from the tire side surface. It is explanatory drawing which shows an example in which the heel and toe abrasion generate | occur | produced in the land part of FIG. It is the elements on larger scale which looked at the block in which heel and toe wear occurred from the tire side.

Explanation of symbols

1 Pneumatic tire 2 Tread surface 3 Land 4 Wear indication line

Claims (5)

  In a pneumatic tire in which at least a land portion made of a block or a lug is connected to at least a shoulder portion of a tread, a wear display in which an inclination angle with respect to a tangential direction of a tread surface is 0.5 ° to 10 ° on an outer surface of the land portion. A pneumatic tire in which land portions in which lines are formed in multiple stages and land portions in which wear display lines having the inclination directions opposite to each other are formed in multiple stages are alternately provided in the tire circumferential direction.   The pneumatic tire according to claim 1, wherein an inclination angle of the wear display line is different from an inclination angle of other wear display lines adjacent to each other.   The pneumatic tire according to claim 1 or 2, wherein a form of the wear display line is different from a form of another wear display line adjacent to each other.   The pneumatic tire according to any one of claims 1 to 3, wherein the tire is a heavy duty tire. The pneumatic tire according to any one of claims 1 to 4, wherein the tire is a studless tire.

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