JPS60252006A - Pneumatic tire - Google Patents

Abstract

PURPOSE:To prevent gravel from being caught in a zigzag groove and easily discharge the gravel caught in the groove by forming gravel catching preventive walls on both side walls of the zigzag grooves continuing in the circumferential direction of a tire on a tire tread surface and specifying measurements and the shape of said, preventive walls. CONSTITUTION:Gravel catching preventive walls 20 are formed respectively on both side walls 10a, 10b of at least one zigzag groove G among zigzag grooves which are arranged laterally at intervals on the tread Ta of a tire T and continuing in the circumferential direction of the tire. Both width and height of said wall 20 are formed the largest specially on ridgelines 11a of projection parts 11 for both side walls 10a, 10b of the zigzag groove G, while both said width and hight are formed the smallest on ridgelines 12a of recessed parts 12 adjacent to the projection parts 11. Further, width and height of said wall 20 formed between the ridgeline 11a of the projection part 11 and the ridgeline 12a of the adjacent recessed part 12 are changed to nearly linear. Thus, prevention of gravel from being caught in the zigzag groove G and easy discharge of the gravel caught in the groove can be attained.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a pneumatic tire, and more particularly, to a pneumatic tire for high-load vehicles such as trucks, lotuses, and light trunks, which have improved stone trapping in the zigzag grooves constituting the tread pattern. This relates to pneumatic tires.

[Conventional technology]

Conventionally, in pneumatic tires for high-load vehicles, the structure of the zigzag grooves that make up the trend pattern has been devised to prevent stones from getting stuck in the zigzag grooves, while also making it easier to release the stuck stones. Attempts have been made to tighten it.

However, the current situation is that none of the conventional means not only cannot obtain a satisfactory effect of reducing stone encroachment, but also that it is difficult to satisfy the driving performance, braking performance, drainage performance, etc. inherent to zigzag grooves. It is.

[Purpose of the invention]

The present invention was developed as a result of experiments and studies aimed at solving two problems.

Therefore, an object of the present invention is to prevent stones from getting into the zigzag grooves that make up the trend pattern, without impairing the important performance of this type of pneumatic tire such as driving performance, braking performance, and drainage performance. An object of the present invention is to provide an excellent pneumatic tire that can easily release trapped stones.

[Structure of the invention]

That is, in the present invention, among the zigzag grooves continuous in the circumferential direction of the tire arranged on the tread surface of the tire, at least one zigzag groove G is provided with stone entrapment prevention walls 20 on both side walls 10a and 10b, respectively. The anti-bite wall 20 has a maximum width and height on the ridgeline 11a of the protrusion 11 of the side walls 10a and 10b, and
The width and height are both minimum on the ridgeline 12a of the concave part 12 that is adjacent to the wall 2, and further, the stone bite prevention wall 2 extends from the ridgeline 11a of the protrusion part 11 to the ridgeline 12a of the concave part 12 that is adjacent to the protrusion part 11.
The gist of the present invention is a pneumatic tire characterized in that the width and height of zero change substantially linearly.

[Embodiments of the invention]

Hereinafter, the present invention will be specifically described by way of examples with reference to the drawings.

1 to 6 show embodiments of the present invention, FIG. 1 is an enlarged perspective view showing the main parts, FIG. 2 is an explanatory plan view of the same, and FIG. Expanded view cross-section diagram, Figure 4 is the second
Figure rV-IY arrow cross section enlarged explanatory diagram, Figure 5 is Figure 2V-
An enlarged explanatory view of the V arrow cross section, Figure 6 shows 50 zigzag grooves as above.
It is a planar view explanatory view when % wear occurs.

The pneumatic tire according to the embodiment of the present invention has at least one zigzag groove G on both side walls of the zigzag grooves continuous in the tire circumferential direction arranged at intervals in the width direction on the tread Ta of the tire T. It is constructed by forming a rock-blocking prevention wall 20 on each of 10a and 10b.

In the present invention, the stone entrapment prevention wall 20 is particularly the both side walls 10a of the zigzag groove G.

The width and height are both the maximum on the ridgeline 11a of the protrusion 11 of the protrusion 10b, and the width and height are the minimum on the ridgeline 12a of the recessed part 12 adjacent to the protrusion 11, and the protrusion 11 The width and height of the rock-blocking prevention wall 20 from the ridgeline 11a of the groove to the ridgeline 12a of the adjacent concave portion 12 change substantially linearly.

Among the zigzag grooves aG that make up the trend pattern, the rock-biting phenomenon is most likely to occur at the bent part where there is a large movement in the tire width direction at the time of contact with the ground. Both side walls 10a
, 1. Since both the width and height of the stone entrapment prevention wall 20 are formed to be maximum on the ridgeline 11a of the protrusion 11 of the Ob, even if a foreign object such as a stone tries to enter the groove G, it will not be able to enter the groove G as shown in FIG. In addition, the upper surface 20a of the stone entrapment prevention wall 20 can prevent foreign matter from entering, and even if the foreign matter is caught between the upper surface 20a of the stone entrapment prevention wall 20 and the opening side of the groove G, This foreign material can be thrown out of the groove as the tread Ta wears out.

Furthermore, even if a foreign object such as a stone enters the groove G at the straight portion other than the above-mentioned bent portion, it will still be blocked by the upper surface 20a of the stone entrapment prevention wall 20, and will be prevented from entering the groove G any further. However, in the present invention, the first
As shown in the drawings and FIG. 5, the width and height of the rock-blocking prevention wall 20 from the ridgeline 11a of the protruding portion 11 to the ridgeline 12a of the adjacent recessed portion 12 are changed linearly. In other words, since the upper surface 20a of the stone entrapment prevention wall 20 is sloped linearly from the bottom of the groove G toward the opening side of the groove G, foreign objects such as stones can be tilted due to the centrifugal force of the tire while driving. It is guided to the opening side of the groove G along the upper surface 20a of the rock-biting prevention wall 20 and can be thrown out of the groove.

Therefore, it is possible to prevent stones from getting stuck in the grooves over the entire length of the zigzag groove G, and it is also possible to easily release foreign objects such as stones that are stuck.

It is preferable that the maximum height Hl of the stone entrapment prevention wall 20 from the groove bottom surface on the ridgeline 11a of the protrusion 11 is set within a range of 70%±10% of the depth D of sG. This means that the maximum height Hl of the stone bite prevention wall 20 is the depth D of the groove G.
If it exceeds 80% of
This is because there is a risk that stones will be caught between 0 and 60%, and if it is less than 60%, the effect of discharging the stuck stones will be reduced, which is undesirable.

Moreover, it is preferable to set the minimum height Hl from the bottom surface of the rock-blocking wall 200)R to a range of 15 to 30% of the depth D of the groove G. This is because if the minimum height Hl of the rock-blocking prevention wall 20 is less than 15% of the depth D of the groove G, the groove width at the bottom of the zigzag groove G will become substantially narrower, and this will affect drainage performance and other problems. This is because there is a risk of impairing the performance that is important for pneumatic tires, and if it exceeds 30%, the effect of the stone entrapment prevention wall 20 in discharging entangled stones will be reduced, which is undesirable. .

Furthermore, on the ridgeline 11a of the protrusion 11,
The maximum width C of the rock-blocking prevention wall 20 is preferably set in a range of 1.5 to 4U. This is because if the maximum @C is less than 1.5H, a good stone bite prevention effect cannot be obtained.
Moreover, if the width exceeds 4, the groove width of the zigzag groove G becomes substantially narrow, which may impede important performance of this type of pneumatic tire such as drainage performance.

Further, as shown in FIGS. 3 and 4, the side wall 20b of the rock-blocking prevention wall 20 is preferably inclined toward the side wall of the zigzag groove G by φ'' with respect to the tire radial direction. This is because, as described above, when the side wall 20b of the stone entrapment prevention wall 20 is inclined toward the side wall of the zigzag groove G, it is possible to further facilitate the release of entrapped foreign substances such as stones.

Next, a case where the above-mentioned zigzag aG is worn out will be explained.

In the case of a conventional zigzag groove G having a cross-sectional shape as shown in Fig. 7, the point high (R) is , there is almost no change.

On the other hand, in the case of the zigzag groove G having the stone bite prevention wall 20 arranged in the present pneumatic tire described above, when the zigzag groove G is worn out by, for example, 50%, as shown in FIG.
The point hide can be made larger than the conventional zigzag groove G shown in FIG.

Therefore, the pneumatic tire of the present invention can improve the driving performance and braking performance, which are closely related to the point hide in the zigzag groove, and is therefore particularly suitable for a pneumatic tire with a reg-lug pattern.

[Experiment example]

Examples of experiments conducted to confirm the effects of the present invention described above will be described below.

Conventional tire: A pneumatic tire with a re-lug pattern on the tread surface of the tire, with three continuous zigzab grooves spaced apart in the width direction and arranged in the circumferential direction of the tire.

Tire of the present invention: Three zigzag grooves continuous in the circumferential direction of the tire are arranged at intervals in the width direction on the tread surface of the tire, and among these zigzag grooves, one zigzag groove located in the center of the tread The stone entrapment prevention wall described above was formed, and the maximum height Hl of this stone entrapment prevention wall was set to 70% of the zigzag groove depth D, and the minimum height I]2 was set to 20% of the zigzag groove depth D. pneumatic tires.

was used to evaluate the number of stones inserted into the zigzag groove and the number of stones that fell off.

The specifications and test conditions of the tire used in this experimental example are as follows.

Tire circumferential direction: 10.00R20141”R Internal pressure:
8. Okg/c+ (rim: 1.50V X20 vehicle 2-D-D dump (10ton loaded fi weight:
10 ton loading measurement method: The number of stones caught in the groove was measured by driving a certain distance on a course consisting of 18% gravel road and 82% paved road, and then the number of stones caught in the groove was measured by driving a certain distance on paved road. Measure the number of stones falling off.

As a result of the experiment, the experimental results shown in Table 1 below were obtained.

From this experimental result, the tire of the present invention can reduce the number of stones stuck into the groove by more than 172 points compared to conventional tires, while at the same time increasing the number of stones stuck in the groove and falling out by more than double. I see that it is possible.

〔Effect of the invention〕

As described above, the present invention includes forming rock-blocking prevention walls 20 on both side walls 10a and 10b of at least one zigzag groove G among the zigzag grooves continuous in the tire circumferential direction arranged on the tread of the tire. Therefore, this rock-blocking prevention wall 20 is formed along the ridge line 11 of the protrusion 11 of the side walls 10a and 10b.
The width and height are both the maximum on the ridgeline 12a of the concave portion 12 adjacent to the protrusion 11, and the width and height are the minimum on the ridgeline 12a of the concave portion 12 adjacent to the protrusion 11.
Since the width and height of the rock-blocking prevention wall 20 from 1a to the ridgeline 12a of the adjacent concave portions 12 are configured to change approximately linearly, this kind of air flow can be improved in terms of driving performance, braking performance, drainage performance, etc. It is possible to prevent stones from getting stuck in the zigzag grooves that make up the trend pattern, and to make it easier to release the stuck stones without interfering with the important performance of the tire.

[Brief explanation of drawings]

1 to 6 show embodiments of the present invention, FIG. 1 is an enlarged perspective view showing the main parts, FIG. 2 is an explanatory plan view of the same, and FIG. Expanded view cross-section diagram, Figure 4 is the second
FIG.
An enlarged explanatory view of the V arrow cross section, Figure 6 shows 50 zigzag grooves as above.
Fig. 7 is a cross-sectional explanatory view of zigzag grooves arranged in a conventional pneumatic tire, Fig. 8 is an explanatory plan view of the same as above, and Fig. 9 is an explanatory view of zigzag grooves as above. It is a plan view explanatory view when 50% has worn out. G... Zigzag groove, 10a... Side wall of the zigzag groove,
10b...Side wall of zigzag groove, 11...Protrusion of side wall in zigzag groove, lla...Ridge line of protrusion, 1
2... Concave portion, 12a... Ridgeline of the concave portion, 20...
・Rock prevention wall, T...tire, Ta...tire tread. Agent Patent Attorney Makoto Ogawa − Patent Attorney Masaru Noguchi Patent Attorney Kazuhiko Saishita Figure 1 Figure 2 Figure 3 Figure 4 Figure 5/υ Figure 6 Figure 7 Figure 8 Figures 1 and 9 figure

Claims (1)

[Claims] Both side walls 1 of at least one zigzag groove G among zigzag grooves continuous in the tire circumferential direction arranged on the tread of the tire
A stone bite prevention wall 20 is formed on each of the side walls 10a and 10b.
Both the width and height are maximum on the ridgeline 11a of the protrusion 11 of b, and the width and height are the minimum on the ridgeline 12a of the recessed part 12 adjacent to the protrusion 11,
Further, concave portions 1 adjacent to each other from the ridgeline 11a of the protruding portion 11
2. A pneumatic tire characterized in that the width and height of the stone entrapment prevention wall 20 up to the ridge line 12a of the tire 20 change substantially linearly.