JPH0593909U - Pneumatic tire for heavy load - Google Patents

Abstract

(57) [Summary] [Purpose] In a tire with a tread pattern that has directionality for rotation, it is possible to clearly display the mounting direction to the vehicle,
Moreover, the indication can be eliminated when tires are rehabilitated. [Structure] A slope S is formed by cutting out an intersection P between a tread surface TS and a buttress surface BS. The slope S
The angle with the tire radius line is 15 to 60 degrees, and a mark indicating the direction of rotation of the tire is formed on the slope S.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 TECHNICAL FIELD The present invention relates to a heavy-duty pneumatic tire capable of clearly indicating a mounting direction on a vehicle in a tread pattern tire having a direction of rotation.

[0002]

[Prior Art]

 In recent years, along with the performance improvement of vehicles, for heavy-duty tires such as trucks and buses, it is required to improve the grounding performance such as traction, low noise and abrasion resistance. For that purpose, a tread pattern having a directivity in which the tire rotation direction is designated is adopted.

The tread pattern having directionality in rotation is, for example, as shown in FIG. 5 (a), an asymmetric pattern in which left and right patterns are greatly different, and as shown in FIG. 5 (b). It is widely known that the lateral groove Y is formed in a substantially V shape. For example, in the case of FIG. 5A, the number of grooves of the tread outer portion T1 facing the vehicle outer side is small and the pattern rigidity is high. Particularly excellent turning performance can be exhibited. In addition, as shown in Fig. 5 (b), since the V-shaped top is grounded, the soil, water, etc. in the construction groove can be efficiently discharged toward both sides of the tire, exhibiting excellent traction and wet grip properties. sell.

However, in such a tread pattern, when the tire is mounted in the direction opposite to the designated direction, the performance is remarkably deteriorated. Therefore, conventionally, in order to mount a tire in a designated rotation direction, for example, as shown in FIG. 6, a marker such as an arrow indicating a designated direction of tire rotation is displayed on the tread surface TS or the sidewall outer surface SS. KU A was formed.

[0005]

[Problems to be solved by the device]

 However, in the former case, the tires are removed and attached from the side of the tire, so that it is inconvenient to check the mark A, and the mark A has already worn out during rearrangement due to rotation and cannot be confirmed. There are problems such as.

On the other hand, in the latter case, the mark A remains even after the tire is rehabilitated, which causes inconsistency with the tread pattern of the rehabilitated tire and causes a lot of confusion to the user and the rehabilitation factory. Met.

It is an object of the present invention to provide a pneumatic tire for heavy loads and tires, which can easily confirm the marks during tire attachment / detachment work including rotation and can remove the marks together with the tread rubber during tire rehabilitation.

[0008]

[Means for Solving the Problems]

 In order to achieve the above-mentioned object, the heavy duty pneumatic tire of the present invention is a tire having a tread pattern having a direction of rotation, and is formed by notching the intersection of the tread surface and the buttress surface in a radial direction. An upper surface and a lower surface are connected to the tread surface and the buttless surface, and a slope having an angle of 15 to 60 degrees with the tire radial line in the tire meridian section is provided. A mark indicating the direction of rotation is formed on the slope and the mark The lower end in the radial direction is located at the upper side in the radial direction from the vicinity of the wear limit position on the tread surface.

A height H between the lower end of the slope and the contour extension line of the tread surface when the tire is new, in a direction perpendicular to the tread surface, is 0. It is preferable that the distance is 6 times or more and 1 time or less, and the upper and lower ends of the mark are located in this slope.

[0010]

[Action]

 A slope is provided at the intersection of the tread surface and the buttress surface, and a mark indicating the tire rotation direction is formed on the slope.

Since the slope makes an angle of 15 to 60 degrees with the tire radial line, the slope can be visually recognized from the side of the tire, and the mark when the tire is attached or detached can be easily confirmed.

Further, since the lower end of the mark in the radial direction is located on the upper side in the radial direction from the vicinity of the wear limit position of the tread surface, the mark can be removed from the base tire by peeling and buffing of the tread rubber during tire retreading. ..

The formation of the sloped surface can suppress heat generation in the shoulder portion by reducing the thickness of the rubber gauge, and can prevent shoulder drop wear by improving the rigidity of the shoulder portion, and can also improve wandering characteristics. Secondary effects can also occur.

[0014]

【Example】

 An embodiment of the present invention will be described below with reference to the drawings. In the figure, a heavy duty pneumatic tire 1 includes a tread portion 2, sidewall portions 4 extending from both ends of the tread portion 2 through a buttress portion 3 in the tire radial direction, and a tire radial inner end. And a bead portion 5 located.

The buttress portion 3 has a buttress surface BS that is in contact with the outer surface of the sidewall portion 4 and is concave in an arc shape. The tread portion 2 is centered on the tire equator C O in this example. It has a tread surface TS having a radius of curvature R that has a convex shape in a single arc shape, and a tread pattern having directionality in tire rotation is formed on the tread surface TS.

In this example, as shown in FIG. 2, the tread pattern has five ribs divided by four zigzag-shaped longitudinal grooves G1, G2, G3, G4 extending in the tire circumferential direction. It comprises profile parts R1, R2, R3, R4, R5. Further, while being arranged on one side of the tire equator CO (on the left side of the tire equator CO), the outer rib-like portions R2, R1 have one end open to the buttress surface BS and the other end to the inner longitudinal groove G2. It is divided into a plurality of blocks by the lateral groove Y1 communicating therewith. Similarly, while being arranged on the other side (on the right side of the tire equator CO), the outer rib-like portions R4 and R5 are divided into a plurality of blocks by the lateral groove Y2, and these lateral grooves Y1 and Y2 are both Incline from the tire equator to the rear of the tire in the direction of rotation. Further, the rib-like portion R3 passing over the tire equator CO is divided into blocks by a V-shaped narrow lateral groove Y3, and the lateral groove Y3 is inclined portions Y3a and Y3b inclined from the top toward the rear in the rotational direction, respectively. It is equipped with

With such a tread pattern, when the tire rotates, the lateral grooves Y sequentially contact the ground from the tire equator side toward the tread end, so that soil, water, etc. in the lateral grooves Y are effectively discharged to the outside of the tire. You can.

On the other hand, when the tire rotating direction is reversed, soil, water, etc. in the lateral groove Y gather on the tire equator side, so that floating occurs between the tire and the ground contact surface, and the grip performance is greatly enhanced. descend.

As described above, since the tread pattern of this embodiment has a direction of rotation in order to exert its performance, the tire 1 of the present invention has the mark K indicating the rotation direction of the tread pattern on the slope S. Formed on.

As the mark K, an arrow-shaped pictorial pattern or the like indicating the rotation direction can be preferably used, and in this example, the mark K is recessed in the slope S by engraving. The depth d of the mark K is preferably in the range of 0.5 to 2.0 mm, and the lower end Kb in the radial direction of the mark K is located above the wear limit position of the tread surface TS in the radial direction.

The inclined surface S is formed by obliquely notching the intersection P between the tread surface TS and the buttress surface BS, so that the upper end Sa thereof is continuous with the tread surface TS and the lower end Sb thereof is the buttress surface BS. Connected to.

The slope S has an inclination angle θ of 15 to 60 degrees with the tire radius line in the meridian section of the tire, which makes it easy to see the mark K from the side of the tire. I am trying.

Further, the height H between the lower end Sb of the slope S and the contour extension line of the tread surface TS when the tire is new is set to be 0.6 times or more and 1 time or less than the groove depth D of the main groove. .. Here, the height H is a height in a direction perpendicular to the tread surface TS, and the vertical groove G and the horizontal groove Y forming the tread pattern are collectively called a main groove. Therefore, when the vertical groove G and the horizontal groove Y have different groove depths, the maximum depth is defined as the groove depth D of the main groove.

When the height H is smaller than 0.6 times the depth D, the slope S is worn away along with the mark K during the middle period of wear, for example, during tire rotation, which makes it difficult to confirm. On the contrary, when the depth D is more than 1.0 times, a part of the slope S remains at the time of tire rehabilitation, which deteriorates the appearance of the rehabilitated tire.

In addition, the formation of the relatively large inclined surface S helps to reduce the thickness of the rubber gauge of the shoulder portion, suppresses heat generation in the shoulder portion, and improves shoulder rigidity to prevent shoulder drop wear. In addition, it is easy to get on the curb and contributes to the improvement of wandering characteristics.

When the mark K is formed directly on the buttress surface BS without providing the slope S, the buttress surface BS is formed as a concave arc so that compression on the surface caused by grounding / non-grounding is performed. However, the tensile deformation is high, and as a result, crack damage such as cracks is likely to occur in the mark K. Therefore, by providing the slope S, the mark K having high durability can be formed.

[0027]

[Effect of the device]

 As described above, in the heavy-duty pneumatic tire of the present invention, the mark can be easily confirmed at the time of tire attachment / detachment work including rotation, and at the time of tire rehabilitation, the mark can be removed together with the tread rubber.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a tire showing an embodiment of the present invention.

FIG. 2 is a development view showing an example of a tread pattern used for it.

FIG. 3 is an enlarged side view showing a slope and a mark.

FIG. 4 is a sectional view thereof.

FIG. 5A is a schematic diagram showing an example of a tread pattern having directionality.

FIG. 5B is a schematic diagram showing another example of the tread pattern having directionality.

FIG. 6 is a schematic diagram showing a conventional technique.

[Explanation of symbols]

 BS Buttress surface G, Y Main groove K Mark P Intersection S Slope TS Tread surface

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location B60C 11/04 C 8408-3D

Claims (2)

[Scope of utility model registration request] 1. A tire having a tread pattern having a direction of rotation, wherein the intersection of the tread surface and the buttress surface is notched obliquely so that the upper and lower ends in the radial direction are continuous with the tread surface and the buttress surface, and the tire. In the meridional section, a slope having an angle of 15 to 60 degrees with the tire radial line is provided, and a mark indicating the direction of rotation is formed on the slope, and the lower end of the mark in the radial direction is measured from the vicinity of the wear limit position of the tread surface in the radial direction. A heavy duty pneumatic tire characterized by being positioned on the upper side. 2. The height H in the direction perpendicular to the tread surface between the lower end of the slope and the contour extension line of the tread surface when the tire is new is 0.
It is 6 times or more and 1 time or less, and the upper and lower ends of the mark are located in this slope, and the heavy duty pneumatic tire according to claim 1.