JP2012176700A - Pneumatic tire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pneumatic tire which is capable of exerting superior steering stability during turning travel for a long time by effectively preventing at least spike pins which are contributed to improve steering stability during turning travel from being unexpectedly displaced in turning within a tread land part.SOLUTION: A pneumatic tire is configured by disposing a plurality of spike pins 4 on a tread grounding surface. A tread grounding width W is equally divided into three areas of a central area 1 and side areas 2 in a tread width direction and in each side area 2, the spike pins 4 with a dimension of a body 4a in the tread width direction being larger than a dimension in a tread circumferential direction are disposed in a land part 3 within the range of 1/6 to 1/12 tread grounding width from the side of the central area 1. On the other hand, the spike pins 4 with the dimension of the body 4a in the tread circumferential direction being larger than the dimension in the tread width direction are disposed in a remaining land part 5 on a tread side edge side of each side area 2.

Description

  The present invention relates to a pneumatic tire in which a plurality of spike pins are disposed on a land portion of a tread contact surface, and in particular, while ensuring excellent driving and braking performance in an icy and snowy road, The present invention proposes a technology that realizes high skid resistance and, in turn, high handling stability over a long period of time.

  Patent Document 1 states that “in a pneumatic tire in which stud pins are embedded in the outer peripheral surface of a tire, among stud pins embedded in the outer peripheral surface of the tire, stud pins that are 50% or more of the total number of pins, It is formed so that the length in the tire circumferential direction is longer than the length in the tire width direction, and is arranged in a range excluding the range of 65% or less of the ground contact width from the center in the tire width direction in the range of 95% of the ground contact width. The pneumatic tire is characterized in that the stud pin to be formed is formed such that the length of the protrusion in the tire circumferential direction is longer than the length in the tire width direction. " “When driving on a snowy and icy road, the edge effect in the width direction of the vehicle can be sufficiently obtained, so that the steering stability during turning can be improved.”

JP 2008-284922 A

  However, the pneumatic tire described in Patent Document 1 is such that the contour shape of the tip protrusion from the stud pin body having a cylindrical shape is a rectangle or the like, and the tire circumference of the tip protrusion in the side region of the tread ground contact surface. Since the direction length is longer than the length in the tire width direction, when the tire is new, even if it can achieve excellent steering stability during turning, the stud pin body is cylindrical, By continuing to use the tire, the stud pin itself is easily rotated and displaced in the tread land due to the input received by the tip protrusion from the road surface. There is a problem that it is impossible to maintain excellent maneuvering stability at the time of turning and continuously for a long period of time.

  The present invention aims to solve such problems of the prior art, and the object of the present invention is at least the spike pin contributing to the improvement of the steering stability during turning, An object of the present invention is to provide a pneumatic tire capable of effectively preventing unintentional rotational displacement in the land portion of the tread and exhibiting “excellent handling stability over a long period of time during turning”.

  The pneumatic tire according to the present invention has a plurality of spike pins arranged on the tread ground surface, and the tread ground width is divided into three in the tread width direction between the central region and each side region. In each side area, the tread width dimension and tread circumference dimension of the body of the spike pin are located on the land area within the range of 1/6 to 1/12 of the tread grounding width from the central area side. While the same or the one whose tread width direction dimension is larger than the tread circumferential dimension is arranged, the tread circumference of the tread pin body is placed on the remaining land part on the tread side edge side of each side area. Those having a dimension in the direction larger than that in the tread width direction are arranged.

  In such a tire, preferably, the body of each spike pin has an out-of-plane contour shape in a virtual orthogonal coordinate system passing through the center of the out-of-plane contour line, such as an ellipse, an oval, a rectangle, etc. centered on the coordinate origin. The length in the axial direction is longer than the length in the other axial direction.

  In the pneumatic tire of the present invention, on the premise that the upper end portion of the spike pin body that protrudes from the surface of the land portion also acts on the road surface, the side region on the central region side that greatly contributes to driving and braking In each part, the spike pin body has a tread width direction dimension and a tread circumferential direction dimension that are the same, or a tread width direction dimension that is larger than the tread circumferential dimension. Each of the driving and braking functions can be exhibited sufficiently effectively in the central area side portion of the area.

  Here, the spike pin may have a tip protrusion, or may have a tip protrusion and a body tip having a depression of a weight shape, a spherical shape, etc. As for the former spike pin with the same tread circumferential dimension, when the spike pin itself is not directional in the scratching action on the snow and snow road surface, etc. It is also possible to have a form that can be rotated and displaced in the section. It is also possible to have a form in which the rotational displacement in the part is restrained by the land part.

In addition, the driving and braking function by the central area side portion of each side area is such that the dimension of the spike pin body in the tread width direction is larger than the dimension in the tread circumferential direction, and the tip of the spike pin body with respect to the snowy and snowy road surface, etc. When the scratching force of the part is further increased, it can be more effectively exhibited.
As described above, when the dimensions of the spike pin body itself are made different between the tread width direction and the tread circumferential direction, the rotational displacement of the spike pin within the tread land portion is effectively prevented by the land portion. Of course.

In addition, in this tire, when the vehicle is turning by placing a spike pin body having a dimension in the tread circumferential direction larger than the tread width direction dimension in the remaining land portion on the tread side edge side in each side region. For example, it is possible to achieve excellent steering stability by exerting excellent skid drag on the tire.
By the way, these spike pins having a directional shape are firmly held in the tread land portion, and the rotational displacement in the land portion is effectively prevented, so that the conventional technique described in Patent Document 1 is used. In comparison, the functions as expected can be sufficiently exhibited over a long period of time.

  In such a tire, the contour shape outside the plane of each spike pin body is an imaginary line orthogonal coordinate system passing through the center of the contour line outside the plane, and the length in one axial direction is longer than the length in the other axial direction. When it is long, oval, oval, rectangular, etc., one type of spike pin can be used properly under the selection of the placement posture according to the application position of each side region, There is an advantage that it is not necessary to prepare different types of spike pins.

It is a partial expansion top view of a tread grounding surface showing an embodiment of this invention by one arrangement mode of a spike pin. It is a figure which illustrates a spike pin. It is a partially expanded plan view similar to FIG. 1 showing another embodiment in another arrangement mode of spike pins. FIG. 6 is a partially developed plan view similar to FIG. 1 showing still another embodiment in another arrangement of spike pins.

The pneumatic tire showing the tread contact surface in FIG. 1 may have an internal reinforcement structure similar to a conventional general radial tire or bias tire.
This pneumatic tire is formed by arranging a plurality of spike pins on the land portion of the tread contact surface.

  Here, the width of the tread contact surface, that is, the tread contact width W is divided into three equal parts in the tread width direction into the central region 1 and the respective side regions 2, and each side region 2 has a central region 1 side. As shown in FIG. 2 (c), the dimension of the body 4a of the spike pin 4 in the tread width direction is applied to the land portion 3 on the center side that exists within a range of 1/6 to 1/12 of the tread grounding width W. While A is larger than the dimension B in the tread circumferential direction, the tread circumferential dimension of the body 4a of the spike pin 4 is tread in the remaining land portion 5 on the tread side edge side in each side region 2. Items larger than the dimension in the width direction are embedded and arranged.

  As shown in the drawing, one type of spike pin 4 that is properly disposed on each land portion 3, 5 has a lower end flange 4 b, a columnar body 4 a, and a middle as illustrated in the front view of FIG. Others can be provided with a real tip protrusion 4c, or, as illustrated in FIG. 2B, a columnar body 4a provided with a constriction 4d adjacent to the lower end flange 4a. Alternatively, the tip protrusion or the body itself without the tip protrusion may be provided with a depression such as a weight or a spherical shape.

  Further, the body 4a of these spike pins 4 shown in the figure can have an out-of-plane contour shape having an elliptical shape as illustrated in FIG.

  Therefore, when the one kind of spike pin 4 having such an elliptical outer contour shape is selectively used for each land portion 3, 5, in the land portion 3, the major axis A of the ellipse is in the tread width direction. In the land portion 5, the ellipse has a major axis A in the tread circumferential direction and a minor axis B in the tread width direction. By disposing the tire, it is possible to cause the tire to exhibit the expected driving and braking performance and steering stability performance over a long period of time.

  Note that, in such an embedded arrangement state of the spike pins 4, the surfaces of the land portions 3 and 5 are present at positions indicated by phantom lines in FIGS. 2 (a) and 2 (b).

  By the way, the out-of-plane contour shape of the spike pin body 4a is not limited to the elliptical shape shown in FIG. 2C, but is a virtual orthogonal coordinate system passing through the center of the out-of-plane contour, The length in the axial direction can be longer than the length in the other axial direction, such as an oval shape, a rectangle, or other polygonal shapes.

  FIG. 3, which shows another embodiment, shows that the elliptic pin out-of-plane contour shape of the spike pin body 4a is arranged in the land portion 3 as compared with that in the land portion 5, and is more flat. It is a thing.

In this case, two types of spike pins are required, but as long as the expected function can be exhibited over a long period of time even with a flatter spike pin, the spike pin is not as shown in FIG. There is an advantage that the weight of the pin, and thus the tire weight can be reduced.
This also applies to the case where the spike pin 4 disposed on the land portion 3 and the spike pin 4 disposed on the land portion 5 are reversed as shown in FIG.

4 showing still another embodiment, the land portion 5 has a spike pin 4 having a body 4a having an elliptical out-of-plane contour similar to that shown in FIGS. 1 and 3, and the land portion 3 has Spike pins 4 each having a body 4a having a circular outer contour shape are embedded and arranged.
In this embodiment, the spike pin body 4a of the land portion 3 has the same dimensions in both the tread width direction and the red circumferential direction. Under the action of the spike pin 4 of the land portion 5, excellent steering stability can be exhibited over a long period of time.

  Although the embodiment shown in the drawings has been described above, a required spike pin can be disposed also in the central region 1 of the tread grounding width W, and the tip protrusion 4c of the spike pin 4 is also an ellipse or the like. It can also be a shape. In this case, it is preferable to make the planar contour shape of the body 4a the same direction as the planar contour shape of the tip protrusion 4c in order to make it difficult to turn the pin 4.

An actual vehicle running test on ice was performed on each of the conventional tire and the actual tire having a size of 195 / 65R15 to obtain steering stability performance and driving performance. The results shown in Table 1 were obtained.
Here, the on-ice handling stability performance was obtained by sensory evaluation by a driver specializing in evaluation, and the higher the score, the better the result.
The on-ice driving performance was obtained by measuring the time required for acceleration from 5 km / h to 20 km / h and performing index evaluation using a conventional tire as a control. It should be noted that the larger the index value, the better the result.

  According to the results shown in Table 1, in the example tire 1, under the action of the spike pin disposed in the land portion 5, it is possible to improve the stability on ice and the steering stability on ice, and the example tire 2 Thus, it can be seen that both the on-ice driving performance and the steering stability performance can be effectively improved by the respective spike pins arranged in the respective land portions 3 and 5 by selecting the orientations.

DESCRIPTION OF SYMBOLS 1 Center area 2 Side area 3 Center side land part 4 Spike pin 4a Body 4b Lower end flange 4c Tip protrusion 4d Constriction 5 Remaining land part W Tread grounding width A Major axis B Minor axis

Claims (2)

A pneumatic tire having a plurality of spike pins arranged on a tread ground surface,
In the tread width direction, the tread ground contact width is divided into three equal parts into the central region and the respective side regions, and in each side region, a range of 1/6 to 1/12 of the tread ground contact width from the central region side. The tread width body dimension and the tread circumferential dimension are the same, or the tread width dimension is larger than the tread circumferential dimension. A pneumatic tire formed by arranging a body of a spike pin having a dimension in a tread circumferential direction larger than a dimension in a tread width direction on a remaining land portion on a tread side edge side in a side region.   The shape of an out-of-plane contour of the body of each spike pin is a virtual orthogonal coordinate system passing through the center of the out-of-plane contour, and the length in one axial direction is longer than the length in the other axial direction. The described pneumatic tire.

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