Measuring and testing – Tire – tread or roadway
Reexamination Certificate
2000-08-28
2002-06-25
Fuller, Benjamin R. (Department: 1773)
Measuring and testing
Tire, tread or roadway
Reexamination Certificate
active
06408689
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Technological Field of the Invention
The present invention relates to an on-snow tire-testing method, an on-snow tire-testing system, and a road surface for the on-snow testing of tires.
2. Background Art
Heretofore, in testing the performance of tires on snow, generally a test course on which snow has accumulated has been used.
Nevertheless, the aforesaid method is problematic in that testing can be performed only during winter, when snow has fallen.
Testing methods have been considered whereby artificial snow is created by finely pulverizing ice or freezing sprayed water, and this artificial snow is spread on a road surface, but the problem is that large-scale facilities are required for this method.
When testing is performed by spreading this type of artificial snow on the road surface, in order to prevent the snow produced from melting, it is necessary to refrigerate a large road surface, to lay the road surface inside an enclosed structure, and to maintain the air temperature inside the structure below the freezing point.
Further, since the snow cannot be reused once it has melted, it must be disposed of as wastewater. When long-term testing is performed, the snow is melted after the completion of testing and must be disposed of in a sewer system as water, and then artificial snow must be created again for the next set of tests, requiring large quantities water.
SUMMARY OF THE INVENTION
The present invention was produced in light of this situation and has an object of offering an on-snow tire-testing method, an on-snow tire-testing system, and a road surface for snow-testing tires, which enables snow testing of tires to be performed at low cost.
The on-snow tire-testing method of the present invention involves testing tires on an artificial snow layer obtained by placing artificial snow in a layered form and cooling the snow. The artificial snow is composed of a granular water-absorbent material that has been made to expand by the addition of water.
In the on-snow tire-testing method according to the present invention, various types of snow tests for tires are performed on the artificial snow layer after it has been cooled. In this way, snow test data for tires can be obtained at any time without requiring snowfall.
Further, since the water is held in the water-absorbent material even if the artificial snow is melted, it returns to the form of artificial snow when cooled and frozen.
The term “cooling” used here means making the artificial snow into a form like that of actual snow, and may involve complete freezing or partial freezing of the artificial snow.
The artificial snow layer may be obtained by placing the artificial snow in a layered form on an ice layer and cooling the snow.
Since the artificial snow changes its form according to the temperature in the same way as actual snow, in order for the artificial snow as a whole to assume a uniform state, it is necessary to reduce temperature irregularities.
By providing an ice layer on the underside of the artificial snow layer, the artificial snow layer as a whole can be maintained at a constant temperature, and snow test data can be obtained with a high degree of reliability with a uniform artificial snow layer.
The ice layer is cooled by means of a cooling device which is arranged on the bottom face of the snow layer and/or the interior of the snow layer.
Even if the air temperature is high (e.g., exceeds 0° C.), the melting of the ice layer and artificial snow layer can be prevented, and the initial road conditions can be maintained. Moreover, depending upon the conditions, the ice layer and artificial snow layer can be maintained at a temperature of 0° C. or less.
The artificial snow may be compressed and used. By compressing the artificial snow, the artificial snow layer assumes a state similar to that of an actual compressed snowy road, for example, and test data is obtained similar to test data obtained when on-snow testing is performed using an actual compressed-snow road.
Various types of road conditions can be reproduced by increasing or decreasing the amount of compression. For example, various road surface conditions from a soft-compressed snow road to a hard-compressed snow road can be reproduced by increasing or decreasing the amount of compression when compressing the artificial snow. Accordingly, snow test data for the desired road conditions can be obtained.
Testing tires is performed on the artificial snow layer which rotates. Since the tire-testing is performed on a rotating artificial snow layer, testing is simpler than when the tire is installed on a test vehicle and driven, and the snow testing of tires can be performed in a smaller space.
A tire is rotated on the artificial snow layer, which is rotated, and slipping between the artificial snow layer and the tire, which is generated by increasing or decreasing the rotational speed.
For example, by increasing the rotational speed of the tire, and setting the circumferential speed of the tire at higher speed than the speed of movement of the artificial snow layer (the portion in contact with the tire), conditions when driving, when accelerating, etc., can be reproduced.
Further, by reducing the rotational speed of the tire, and setting the circumferential speed of the tire at lower speed than the speed of the movement of the artificial snow layer (the portion in contact with the tire), conditions such as those of deceleration can be reproduced.
The tangential direction of rotation of the artificial snow layer and the direction of the equatorial plane of the tire can be made to differ, and the tire is thereby provided with a slip angle. Snow-testing data when the tire is provided with a slip-angle can therefore be obtained.
By increasing or decreasing the water absorption factor by 10 to 100 times, various road surface conditions can be reproduced. That is, by increasing or decreasing the water added to the granular water-absorbent material by 10 to 100 times the weight (mass) of the water-absorbent material, artificial snow having various states can be obtained, and various road surface conditions similar to actual road surfaces can thereby be reproduced. Accordingly, snow-testing data can be obtained for the desired road surface conditions.
The artificial snow layer is also able to reproduce various road surface conditions by increasing or decreasing the temperature of the artificial snow layer and/or the ice layer. Accordingly, on-snow test data for a desired set of road conditions can be obtained.
The water-absorbent material is preserved and reused. After the completion of testing, the artificial snow, i.e., water-absorbent material, is preserved and can be reused for the next test. Accordingly, it is not necessary to prepare a new water-absorbent material for each test, testing can be performed with a minimal quantity of water-absorbent material, and the cost of testing can be minimized.
The water-absorbent material is preserved in a gel form containing water. Since the artificial snow, i.e., water-absorbent material, is preserved in a gel form containing water, it is not necessary to add water when performing the next test. When the moisture in the gel evaporates due to storage conditions, an amount water equivalent to the amount evaporated is injected.
The on-snow tire-testing system includes an artificial snow layer arrangement device, which arranges artificial snow composed of a granular water-absorbent material made to expand by the addition of water in a layered state, a cooling device, which cools the artificial snow layer, and a tire-testing device, which can rotate and which supports the tires and performs testing on the tires on the artificial snow layer.
The tire-testing device has a tire pressing device, which presses the tire on the artificial snow layer. Thus, the load applied to the tire can be easily changed in comparison with cases where testing is performed by driving a test vehicle on which tires have been installed, and testing can be performed by applying various loads to the tires.
The tire-t
Fukuda Kouichi
Usami Koichi
Yamanoi Kazuyuki
Bridgestone Corporation
Fuller Benjamin R.
Sughrue & Mion, PLLC
Thompson Jewel V.
LandOfFree
On-snow tire-testing method, on-snow tire-testing system,... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with On-snow tire-testing method, on-snow tire-testing system,..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and On-snow tire-testing method, on-snow tire-testing system,... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2891464