JPH08318712A - Pneumatic tire for heavy load and mounting method therefor - Google Patents

Abstract

PURPOSE: To provide the pneumatic tire for a heavy load and the mounting method thereof which can improve an anti-eccentric wear property and a noise performance without hurting a traction performance. CONSTITUTION: The tire in the title is constituted by providing a tread pattern with a lag basis on the tread surface 1a on more one side than a tread center line CL and the tread pattern with a rim basis on the tread surface 1b on the other side, and is mounted on a vehicle so that the tread surface 1b on the other side provided the tread pattern with the rim basis may be the outside of the double wheel X, when this tyre is used as a double wheel X by right/left pair.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heavy duty pneumatic tire used for trucks, buses and the like and a method of mounting the same, and more specifically, it improves uneven wear resistance and noise performance without impairing traction performance. And a mounting method thereof.

[0002]

2. Description of the Related Art In heavy-duty vehicles such as trucks and buses,
Mainly, the front wheel is a single wheel, and the rear wheel is a double wheel composed of a pair of left and right tires. Generally, tires having a rib-based tread pattern for steering are used for the front wheels, tires having a lug-based tread pattern are used for the rear wheels from the viewpoint of traction performance, or maintenance, storage of spare tires, etc. in view of,
Tires having a tread pattern with a lag tone are used for both the front and rear wheels.

By the way, in the above heavy-duty vehicle, the rear wheels, to which a large amount of load is applied, are likely to be worn out easily, and like the case where a single wide tire is used, the inner portion of the compound wheel is used. On the outer side, there is a problem of uneven wear in that the outer side wears faster. Therefore, as a solution to the above, there is a proposal to arrange the lug grooves formed on the outer side in an inclined manner.
It could not be a sufficient solution, and a new proposal was desired. Further, from the viewpoint of vehicle noise regulations becoming stricter year by year, there is a strong demand for reducing the noise of even heavy-duty pneumatic tires.

[0004]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a heavy duty pneumatic tire capable of improving the uneven wear resistance and the noise performance without impairing the traction performance and a method of mounting the pneumatic tire. It is in.

[0005]

Means for Solving the Problems A heavy duty pneumatic tire of the present invention that achieves the above object is provided with a lug-based tread pattern on one side of a tread center line and a rib-based tread on the other side. It is characterized in that a pattern is provided. Further, the method for mounting a heavy duty pneumatic tire of the present invention is a heavy duty pneumatic tire having a lug-based tread pattern on the tread surface on one side of the tread center line and a rib-based tread pattern on the other side. When a pair of left and right wheels are used as a compound wheel, the other side provided with a rib-based tread pattern is mounted on the vehicle with the other side being the outside of the compound wheel.

As described above, one side has a tread pattern based on lugs and the other side is formed into a tread pattern based on ribs, and when the tread pattern is used as a compound wheel, the tread pattern based on ribs is provided on the other side. Since the sides are arranged on both sides of the compound wheel, wear on the outer part of the compound wheel is made slower than when a conventional lug-based tread pattern is provided on the outer part, and a lug-based tread pattern is provided. It is possible to wear the same as the inner portion in which the is arranged. Therefore, the uneven wear resistance of the compound wheel can be improved.

As in the conventional case, the lug-based tread pattern for improving the traction performance is provided on the inner side of the compound wheel that affects the traction performance, so that the traction performance does not deteriorate. Also, since one side is a rib-based tread pattern, the ratio of the lug pattern that causes noise to the tread surface decreases,
As a result, noise performance can be improved.

Furthermore, since the outer side portion which affects the braking performance in the compound wheels is formed by the rib-based tread pattern, the braking performance is improved as compared with the conventional case in which the lug-based tread pattern is arranged on the outer side portion. It is also possible. Hereinafter, the configuration of the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 shows an example of a heavy duty pneumatic tire of the present invention. On the tread surface 1, a plurality of lug grooves 2 extending along the tire width direction are arranged in the tire circumferential direction A at predetermined intervals on the tread surface 1a on one side of the tread center line CL. A tread pattern with a lag tone is provided.

On the tread surface 1b on the other side of the tread center line CL, one circumferential groove 3 extending linearly in the tire circumferential direction A is provided, and ribs 4 are provided on both sides thereof. The rib-based tread pattern provided is formed, and the tread surface 1 is provided with a laterally asymmetric tread pattern. When the heavy-duty pneumatic tire T having the above-described configuration is used as a pair of wheels X on the rear wheel of the vehicle by pairing the pair of tires left and right, as shown in FIG. The rear wheel shaft RS of the vehicle is arranged such that the tread surface 1a on one side faces the inner side so as to be on the inner side of X, and the tread surface 1b on the other side provided with a tread pattern having a rib-based tone is the outer side of the compound wheel X. Be attached to. The compound wheel X connects between the left and right heavy-duty pneumatic tires T by connecting between the protruding portions R of the rim protruding toward the tread surface 1a side provided with the tread pattern of the lag tone.
Are fixed to each other.

As described above, according to the present invention, the heavy duty pneumatic tire T has an asymmetrical tread pattern in which the tread surface 1a on one side is provided with a lug-based tread pattern and the other side is formed with a rib-based tread pattern. When using it as the compound wheel X, the tread surface 1b side provided with the rib-based tread pattern is arranged so as to be on both outsides of the compound wheel X, and only the inner portion of the compound wheel X is a lug-based tread. Since the tread surface 1a is provided with the pattern, the wear on the outer portion of the compound wheel X is made slower than in the case where the conventional outer portion is also the lug-based tread pattern, and the lag-based tread pattern is arranged. It can be worn to about the same extent as the inner part, which allows the compound wheels X
It is possible to improve uneven wear in the. The inner portion of the compound wheel X, which influences the traction performance, is provided with a lug-based tread pattern as in the conventional case, so that the traction performance is not impaired.

Further, since the ratio of the lug pattern that causes noise to the tread surface 1 is reduced, the noise performance can be improved, and the outer side portion that bears the braking performance of the compound wheel X has a rib-based tread. Since it is composed of patterns, it is possible to improve the braking performance as compared with the conventional case in which a tread pattern having a lag tone is arranged. The heavy duty pneumatic tire T can also be used as a single wheel for the front wheels. In that case, as shown in FIG. 2, the tread surface 1a on one side on which the tread pattern of the lag tone is arranged.
It can be mounted on the front wheel shaft FS so that the side is the inside of the vehicle and the other side of the tread surface 1b provided with the rib-based tread pattern is the outside of the vehicle. As a result, since the vehicle outer side of the front wheels, which are the steered wheels, has a rib-based tone, it is possible to secure a higher cornering force than in the conventional case where a tire having only a lug-based tread pattern is used for the front wheels.

The heavy duty pneumatic tire T of the present invention
Can be used with the above-described mounting method for both the front and rear wheels of a heavy-duty vehicle, which can facilitate maintenance and storage of spare tires. As a spare tire, since the rear wheels are double wheels, it is unlikely that both will puncture at the same time, so it is advisable to install a rim for the single wheel used for the front wheels. When used as a single wheel,
The protruding portion R of the rim is in a state of protruding toward the tread surface 1b side on which the rib-based tread pattern is provided.

According to the present invention, in the above-mentioned compound wheel X, when a regular load is applied when the vehicle is mounted, the actual tread surface 1a of the inner portion (between both tread center lines CL) provided with the tread pattern of the lag tone is actually used. The ratio of the ground contact area is in the range of 30 to 80% with respect to the actual ground contact area of the tread surface 1b of both outer side portions (outer side of the compound wheels from both tread center lines CL) provided with the rib-based tread pattern. Thus, it is preferable to configure a pair of left and right pneumatic tires T for heavy load to be combined.

When the ratio of the ground contact area is less than 30%, the inner part wears more than the outer part, and when it exceeds 80%, the outer part wears more than the inner part. Uneven wear tends to occur. The ground contact areas on the tread surfaces 1b on both outer sides are preferably the same. Further, when the compound wheels X are mounted on the left and right sides of the rear wheels of the vehicle as shown in FIG. 2, as shown in FIG. 3, the four heavy-duty pneumatic tires T constituting the two compound wheels X are the maximum. It is preferable that the reinforcing cords c of the outer belt layer Tb are all oriented in the same direction at the same inclination angle. By thus aligning all the reinforcing cords c of the belt layer Tb in the same orientation direction, the force acting on the treads of both compound wheels X can be released in the same direction, so that wear can be further suppressed.

FIG. 4 shows another example of the heavy duty pneumatic tire of the present invention. In the above-described embodiment, a block-based tread pattern is provided instead of the lug-based tread pattern provided on the tread surface 1a on one side of the tread center line, and a tread surface 1 having a left-right asymmetrical tread pattern is formed. Is. A large number of blocks B are partitioned and formed on the tread surface by the two linear circumferential grooves 6 and the plurality of lateral grooves 7. Instead of the linear circumferential groove 3 described above, the zigzag circumferential groove 3 is formed on the tread surface 1b on the other side, and ribs 4 are arranged on both sides thereof. By using the heavy-duty pneumatic tire T ′ having such a configuration as described above,
The same effect as described above can be obtained.

FIG. 5 shows still another example of the heavy duty pneumatic tire of the present invention. Also in this embodiment, as in the embodiment of FIG. 4, a tread pattern having a block-based tone is provided on the tread surface 1a on one side, and a tread pattern having a rib-based tone is provided on the tread surface 1b on the other side. Is configured. The block B is partitioned and formed on the tread surface 1a by one thick circumferential groove 8 extending in the tire circumferential direction T in a zigzag manner so as to extend to the shoulder portion. The tread surface 1b on the other side is provided with one zigzag circumferential groove 3 having a groove width narrower than that of the circumferential groove 8 and having a zigzag pitch longer than that of the zigzag circumferential groove of FIG. The ribs 4 are arranged on both sides of the rib 4. It is needless to say that the same effect as described above can be obtained by using the heavy duty pneumatic tire T ″ having such a configuration as described above.

Further, in the present invention, in the above-described embodiment, when the double wheels X are constructed, the heavy load pneumatic tires having the same tread pattern are combined, but the heavy load pneumatic tires of FIGS. 1 and 4 are combined. Pneumatic tires,
The compound tire X may be configured by combining the heavy duty pneumatic tires of FIGS. 1 and 5 or the heavy duty pneumatic tires of FIGS. 4 and 5.

[0018]

[Example] Tire size is 10.00R20 14PR
In the tire of the present invention, which has the same asymmetrical tread pattern as shown in FIG. 1, and the tread surface on the other side in the configuration shown in FIG. A conventional tire 1 and a conventional tire 2 in which the lug groove of the tread surface on the other side of the conventional tire 1 was inclined were manufactured.

A rim size of 20 × is applied to each of these test tires.
It is mounted on a rim of 7.50V, and is constructed with multiple wheels with an air pressure of 7.25kgf / cm ² , and is attached to the rear wheel of a truck with a loading capacity of 10t. When the traction performance evaluation test was performed, the results shown in Table 1 were obtained. The ratio of the contact area of the tread surface on the inner side to the contact area of the tread surface on both outer sides of the compound wheel of the tire of the present invention is 72%, and the ratio of the compound wheels of the conventional tires 1 and 2 is 100%. Uneven wear resistance After running 40,000 km on a general pavement, the difference in the amount of wear between the outer side and the inner side of the compound wheel was measured, and the result was evaluated as an index value with the conventional tire 1 being 100. The larger this value, the better the uneven wear resistance. Noise performance The sound pressure level of the passing sound when traveling straight on a paved road surface was measured, and the result was evaluated by an index value with the conventional tire 1 being 100. The larger this value, the better the noise performance. Panelists (test driver) on the traction performance test course
A feeling test according to the above was performed, and the result was evaluated by an index value with the conventional tire 1 being 100. The larger the index value, the better the traction performance.

[0020]

[Table 1] As is clear from Table 1, the tire of the present invention can improve the uneven wear resistance and the noise performance without deteriorating the traction performance when used as a compound wheel.

[0021]

As described above, the heavy duty pneumatic tire of the present invention has a lug-based tread pattern on the tread surface on one side of the tread center line and a rib-based tread pattern on the other side. When using it as a compound wheel, by installing it on the vehicle with the other side provided with a tread pattern of a rib-based tone being the compound wheel outer side, without impairing traction performance, uneven wear resistance and Noise performance can be improved.

[Brief description of drawings]

FIG. 1 is a front view showing an example of a heavy duty pneumatic tire of the present invention.

FIG. 2 is an explanatory view showing an example in which the heavy duty pneumatic tire of FIG. 1 is mounted on a front wheel shaft and a rear wheel shaft.

FIG. 3 is an explanatory view showing an orientation state of reinforcing cords of an outermost belt layer of a heavy duty pneumatic tire in a compound wheel mounted on both left and right sides.

FIG. 4 is a front view showing another example of the heavy duty pneumatic tire of the present invention.

FIG. 5 is a front view showing still another example of the heavy duty pneumatic tire of the present invention.

[Explanation of symbols]

1 tread surface 1a tread surface on one side 1b tread surface on the other side 2 lug groove 3 circumferential groove 4 rib A tire circumferential direction B block T, T ', T''heavy duty pneumatic tire X double wheel CL tread center line Tb Outermost belt layer c Reinforcing cord

Claims (6)

[Claims] 1. A heavy-duty pneumatic tire having a lug-based tread pattern on one side of the tread centerline and a rib-based tread pattern on the other side. 2. The heavy duty pneumatic tire according to claim 1, wherein a block-based tread pattern is provided instead of the lug-based tread pattern. 3. When using the heavy-duty pneumatic tire according to claim 1 or 2 as a pair of left and right wheels for use as a compound wheel, the other side provided with a tread pattern having a rib-based tone is located outside the compound wheel. How to install heavy duty pneumatic tires to be installed in vehicles. 4. When the pneumatic tire for heavy load according to claim 1 or 2 is used as a single wheel, the heavy load pneumatic tire is mounted on a vehicle with the other side provided with a tread pattern having a rib-based tone facing the outside of the vehicle. How to install the inner tire. 5. In a compound wheel consisting of a pair of left and right wheels mounted by the method for mounting a heavy duty pneumatic tire according to claim 3, the ratio of the ground contact area of the tread surface of the inner part provided with the tread pattern of a lug-based tone is 3 for the ground contact area of the tread surface on both outer sides with rib-based tread patterns
Pneumatic tire for heavy load with 0-80%. 6. A heavy load that composes a pair of left and right compound wheels mounted by the method for mounting a heavy duty pneumatic tire according to claim 3, when the compound wheels are mounted on both left and right sides of a vehicle. A pneumatic tire for heavy loads in which all reinforcing cords of the outermost belt layer of the pneumatic tire for heavy use are oriented in the same direction.