JPH06328902A - Combined tire for vehicle - Google Patents

Abstract

PURPOSE:To provide a combined tire for vehicle which enables prolongation of service life against wear of dual tires as a whole even if it is used without carrying out rotation. CONSTITUTION:In pneumatic tires 6, 6 to be mounted on a pair of dual tires 4 on the right and left respectively, a pattern of a tread 7 differs each other on both sides of equatorial line E of tire and has asymmetrical structure in which actual ground contact area A on the outside of dual tires from the equatorial plane E of tire is larger than actual ground contact area B on the inside of dual tires by 10 to 35%.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle tire assembly mounted on a pair of left and right compound wheels.
The present invention relates to an assembled tire for a vehicle that can extend the wear life of the entire compound wheel even if it is used without rotation.

[0002]

2. Description of the Related Art Generally, in a vehicle, tires are rotated to wear each tire on an average, thereby preventing uneven wear and extending the wear life. However, industrial vehicles equipped with dozens of tires, such as on-site transportation vehicles, that have dozens of tires due to the double-wheel structure, are used under high load conditions and high operating rates, and are also biased in vehicle characteristics and operating modes. Therefore, despite the fact that the tires are worn down more heavily than ordinary vehicles, the number of tires is so large that rotation of the tires takes too much time and causes a drop in the operating rate. Not done. Therefore, in the tire mounted on the compound wheel, each tire has an early disappearance of only the groove on the tread outside the compound wheel from the tire equator,
Even though the groove on the tread inside the compound wheel is sufficiently left, it will be replaced with a new tire as the tire life.
The financial loss was great.

[0003]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a vehicle tire assembly capable of extending the wear life of the entire compound wheel even if it is used without rotation. .

[0004]

A vehicle tire assembly of the present invention for achieving the above object is a vehicle tire assembly mounted on a pair of left and right compound wheels, wherein the tread pattern of each tire is set to the tire equator. It is characterized by having an asymmetrical structure in which the actual contact area on the outside of the compound wheel from the tire equator is made 10 to 35% larger than the actual contact area on the inside of the compound wheel.

As described above, in the compound wheel tire, the tread patterns of the respective tires are made different from each other on both sides of the tire equator, and the actual ground contact area from the tire equator to the outside of the compound wheel is 10 to 10 times larger than the actual contact area to the inside of the compound wheel. By increasing the size by 35%, the wear characteristics that only the tread rubber on the outer side of the compound wheel is worn down can be alleviated and the tread can be worn evenly on the left and right, so even if it is used without rotation,
The wear life of the compound wheels as a whole can be extended.

In the present invention, the tire may be either a pneumatic tire or a solid tire. Also, the actual ground contact area is JATM for pneumatic tires.
A Grounding area excluding the non-grounded portion of the groove when grounded at 80% of JATMA maximum load at standard air pressure. For solid tires, it is the same grounding area when grounded at 80% of JATMA maximum load. .

The structure of the present invention will be described in detail below with reference to the accompanying drawings. FIG. 1 shows a multi-wheel structure of a yard transportation vehicle in which 32 tires are mounted per vehicle, and FIG. 2 shows a tread pattern of a tire assembly for industrial vehicles according to an embodiment of the present invention. . In the figure,
The axle 1 is axially supported by a bearing portion 3 at the lower end of a support frame 2, and compound wheels 4 each consisting of a pair of left and right wheels are attached to both ends of the axle 1. Each compound wheel 4 is provided with a pair of left and right rims 5 and 5 on one wheel 40, and the pair of left and right rims 5 and 5 are respectively provided with pneumatic tires 6 and 6.
6 is installed.

The tread 7 of the pneumatic tire 6 is provided with a plurality of lug grooves 8 extending from both shoulder ends toward the tire equator E in the tire width direction. These lug grooves 8 have different pitch intervals on both sides of the tire equator E, so that the actual ground contact area A on the outside of the compound wheel from the tire equator E is 10 to 35% larger than the actual ground contact area B on the inside of the composite wheel. It has an asymmetric structure. Further, the length and width of the lug groove 8 may be different on both sides of the tire equator E to form a tread pattern having an asymmetric structure.

In the compound wheel structure as described above, when the tread pattern of the pneumatic tire 6 is a bilaterally symmetrical structure, the tread rubber on the compound wheel outer side of the pneumatic tire 6 is inside the compound wheel as shown by the broken line in the figure. Compared with other tread rubbers, it wears earlier and tends to wear evenly. However, for the two left and right pneumatic tires 6 and 6 mounted on the compound wheels as in the present invention, the actual ground contact area A outside the compound wheels from the tire equator E is larger than the actual ground contact area B inside the compound wheels. Then, since the volume of the tread rubber on the outer side of the compound wheel becomes relatively large, the above-mentioned uneven wear characteristics can be alleviated and the tread 7 can be evenly worn on the left and right sides. Therefore, in a vehicle such as a yard transportation vehicle equipped with a large number of tires, even wear can be prevented without rotating the tires, and the entire tread rubber can be efficiently consumed. The life can be extended.

In the present invention, the actual ground contact area A on the outer side of the compound wheel from the tire equator E is 10 more than the actual ground contact area B on the inner side of the compound wheel.
Increase by ~ 35%. That is, [(A−B) / B] ×
100 to 10-35%. Actual contact area B inside the compound wheel
If the increase rate of the actual ground contact area A on the outer side of the compound wheel is less than 10%, the effect of preventing uneven wear on the outer side of the compound wheel is insufficient, and the economic effect of manufacturing a new mold is expected. On the other hand, if it exceeds 35%, conversely, wear will occur inside the compound wheels, and other running performance will deteriorate due to the asymmetric structure. One-sided wear in a compound wheel structure is a phenomenon unique to the vehicle and usage conditions, and the amount of uneven wear is not necessarily uniform. Therefore, the increase rate of the actual ground contact area A on the outer side of the compound wheel is appropriately selected from the above range of 10 to 35% in consideration of the vehicle and usage conditions.

The tread pattern provided on the tire of the present invention has an actual ground contact area A on the outer side of the compound wheel around the tire equator E.
The shape of the tread pattern is not particularly limited as long as it is larger than the actual ground contact area B on the inner side of the compound wheel by 10 to 35%, and a lug pattern, a rib pattern, a block pattern, or the like should be adopted. You can If the actual ground contact area A on the outer side of the compound wheel from the tire equator E is made larger than the actual ground contact area B on the inner side of the compound wheel, the groove area on the outer side of the compound wheel becomes smaller, and in an extreme case, a slick pattern without grooves is formed. In this way, it is possible to use a slick pattern on the outside of the multiple wheels, but since the slick pattern is disadvantageous for slip characteristics on wet road surfaces and internal heat generation characteristics during running, in the use environment where these characteristics are required, It is preferable that the actual ground contact area B on the inner side of the compound wheel is set to be relatively small so that sufficient grooves are secured on the outer side of the compound wheel even if the above relationship is satisfied.

[0012]

[Example] Tire size is ID 1200-20 20P
In an assembled tire for an industrial vehicle having R as a tread pattern as shown in FIG. 2, the pitch intervals of the lug grooves arranged inside the compound wheels are made constant, and the pitch intervals of the lug grooves arranged outside the compound wheels are changed. By doing so, the conventional tires, the tires 1 to 3 of the present invention and the comparative tires 1 to 3 in which only the actual ground contact area outside the compound wheel from the tire equator were variously manufactured. The actual ground contact area on the outside of the compound wheel is shown by an index with the actual contact area on the inside of the compound wheel as 100.

With respect to these conventional tires, tires 1 to 3 of the present invention and comparative tires 1 to 3, the wear life and the residual groove ratio on one side were evaluated by the following test methods, and the results are shown in Table 1 below. Abrasion life: A test tire was mounted on a yard transportation vehicle having a compound wheel structure as shown in Fig. 1, and the vehicle was run without rotation. Either one of the compound wheel inner side and the compound wheel outer side of the tread had an abrasion life. The distance to reach was measured.
The evaluation result is shown by an index with the conventional tire being 100. The larger the index value, the longer the wear life.

Residual groove ratio on one side: After the above test, the groove depth of the lag groove remaining on the inside or outside of the compound wheel of the tread was measured, and the groove ratio on one side was calculated based on the following equation (1). . A positive value for this one-sided residual groove ratio means that uneven wear has occurred on the outside of the compound wheel, and a negative value means that uneven wear has occurred on the inside of the compound wheel. .

[0015]

[0016] As can be seen from Table 1, in the tires 1 to 3 of the invention, the residual groove ratio on one side was small, the entire tread rubber was uniformly worn, and the wear life was extended as compared with the conventional tire.
On the other hand, the comparative tires 1 and 2 have a longer wear life than the conventional tires, but the actual contact area on the outer side of the multiple wheels is excessively increased, and therefore the worn wear occurs on the inner side of the multiple wheels.
In addition, the comparative tire 3 had a small increase in the actual ground contact area on the outer side of the compound wheel, and therefore, the extension of the wear life was insufficient.

[0017]

As described above, according to the present invention, in a vehicle tire assembly mounted on a pair of left and right compound wheels, the tread patterns of the tires are different on both sides of the tire equator, and the tire equator is different from each other. Since the actual contact area on the outside of the compound wheel is made 10 to 35% larger than the actual contact area on the inside of the compound wheel, the wear characteristics that only the tread rubber on the outside of the compound wheel of each tire is worn away are alleviated, Since the tread can be worn evenly on the left and right sides, the wear life of the entire compound wheel can be extended even if the tread is used without rotation. Further, the tire assembly of the present invention is preferably used for construction vehicles as well as industrial vehicles.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a compound wheel structure of a yard transportation vehicle in which a tire assembly of the present invention is used.

FIG. 2 is a plan view showing a tread pattern of a tire assembly for industrial vehicles according to an embodiment of the present invention.

[Explanation of symbols]

 4 compound wheels 6 pneumatic tires 7 tread 8 lug groove A actual contact area outside compound wheels B actual contact area inside compound wheels

Claims (1)

[Claims] 1. In a combined tire for a vehicle mounted on a pair of left and right compound wheels, the tread pattern of each tire is different on both sides of the tire equator, and the actual ground contact area outside the compound equator from the tire equator is compound wheel. 1 more than the actual ground contact area inside
A combined tire for a vehicle having an asymmetric structure that is increased by 0 to 35%.