JP3069594B2 - Vehicle mounting method for asymmetric tires - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for mounting a vehicle having an asymmetrically structured tire, and more particularly to a method for mounting a vehicle having an asymmetrically structured tire for improving cornering performance of a front drive vehicle (FF vehicle).

[0002]

2. Description of the Related Art It is known that the behavior of a front-drive vehicle during cornering generally indicates a tendency to go outward, that is, understeer (U / S). This is basically because the same tires are used on the front and rear wheels,
A front wheel with a large load and a large tire slip angle generates a larger cornering force (CF) than the rear wheel, but at the same time, a driving force is applied to the front wheel, so that the front wheel cornering force is reduced and the rear wheel cornering force is reduced. Is larger, which causes U / S. Needless to say, basically, the vehicle is ideally neutral steer, and it is necessary to take some measures against such U / S. This leads to improved cornering performance of vehicles, especially motorsport vehicles.

Therefore, various studies have been made on U / S countermeasures in terms of both improvement of the vehicle side and improvement of tires.
To improve the tire side, make the CF of the front wheel larger than that of the rear wheel. For example, make a difference in the tire structure attached to the front and rear wheels, change the CF size by changing the rigidity of the side part, and change the tire size. Attempts have been made to change the size of the CF by changing the rim size, while the camber angle of the front wheels (the angle between the ground and the center of the tire) has been improved as a vehicle.
Attempts have been made to increase the front tire capacity by taking large amounts in the negative direction. However, in each of the above methods, completely different tires are required for the front and rear wheels, and if the camber angle is increased, uneven wear is caused, which is inevitable. For this reason, recently, one side of the tire is reinforced more strongly than the other side to increase the rigidity, while the tread rubber is divided into two parts, and the hardness of one side is made lower than that of the other side. Or, when mounting on a vehicle with a large camber angle in the minus direction according to the camber angle of the vehicle using an asymmetrical structure tire with a slightly thicker tread at the end of the tread, one side of the tire on the outside of the vehicle and on the inside If the tire is mounted so that the other side of the tire is located on the vehicle, and conversely, the vehicle is mounted on the vehicle at a large camber angle in the plus direction, the tire should be mounted on the outside of the vehicle and on the inside with one side of the tire positioned. Has been proposed. (See JP-A-2-185802)

[0004]

However, even when the tire is mounted on a car at a camber angle in the minus direction, the tire mounting method as described above can sufficiently improve the wear resistance, heat resistance, and high grip of the tread of the tire. Although it is evaluated in the point that it can be maintained for the time being, it is not possible to follow the difference in the cornering force of the front and rear wheels described above because both the front wheel and the rear wheel are mounted so that the rigidity on the outside or inside is increased similarly, As a result of the feeling test, it was found that it was not enough.

The present invention is based on the above findings, and further attempts to improve it. By using the asymmetric tire and mounting it in the opposite direction, the exercise performance required for the front and rear wheels is taken into consideration and adapted. The purpose of the present invention is to reduce understeer and improve cornering performance.

[0006]

That is, a feature of the present invention that meets the above-mentioned object is that the one side portion has a greater rigidity than the other side portion in the tire circumferential direction as described above. A structural tire is used in which the front wheel is mounted on the vehicle such that the inner stiffness is increased, while the rear wheel is mounted with the same tire on the opposite side so that the outer stiffness is increased.

[0007]

In general, it is known that a tire contributes to improvement of exercise performance by increasing rigidity inside the vehicle in the circumferential direction. In other words, when the outer rigidity is increased, the exercise performance is reduced.

On the other hand, the cause of the understeer is derived from the fact that the driving force is applied to the front wheels, so that the cornering force of the front wheels decreases and an imbalance occurs with the cornering forces of the rear wheels. Therefore, when the front wheel is mounted so as to increase the inner rigidity and the rear wheel is mounted so as to increase the outer rigidity as in the present invention, the exercise performance is improved in the front wheel, and conversely, the exercise is improved in the rear wheel side. The performance is reduced, and the kinetic performance of the front and rear wheels and the cornering force are balanced, understeer is minimized, and the cornering performance is improved.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, specific examples of the method of the present invention will be described with reference to the accompanying drawings.

FIG. 1 shows the front wheel side and FIG. 2 shows the rear wheel side, and FIG. 1A shows an asymmetric tire.
As is known, a carcass extending substantially radially between a pair of bead cores and having a folded portion turned around the beat core, a belt extending circumferentially outside the crown portion of the carcass, and a belt radially outside the belt. It has a tread to cover and side walls to cover the outside of the side portion of the carcass.Also, the number of reinforcing layers on the side portion of the tire is different, and the turn height of the turn portion of the carcass from the bead core to the tread side is different. Or use a material having higher rigidity on one side than the other side, that is, using an organic fiber cord on the other side, a steel cord on one side, or a material having higher rigidity on one side than the other side, for example, the same material Asymmetric structure where one side of the tire has high rigidity by using a material with a large number of driving or a material with a large cord diameter It is constructed by. According to the present invention, the side (1a) of the asymmetrical structure tire (1) having the higher rigidity is mounted on the front wheel side inside the vehicle and on the rear wheel side oppositely outside. .
This is based on the finding that, in general, the inner stiffness of the vehicle is increased to improve the kinetic performance, and conversely, if the outer stiffness is increased, the kinetic performance is reduced. In the figure, α and β are the camber angles of the front wheel and the rear wheel, and they need not necessarily be the same.

Next, in order to confirm the effectiveness of the present invention,
Tire size 180 / 595R16 as test tire
A symmetric tire having two steel belts, two rayon plies, and one steel side reinforcing material; and in the symmetrical structure tire, one side reinforcing material on one side in the tire circumferential direction is one piece of steel, and the other side is one. Asymmetrically structured tires with two side reinforcements made of two steels were produced, and these were run on a circuit on a real vehicle. Driving feeling tests such as controllability, brake traction, and side rigidity, and the best lap time Were compared. The results are shown in Table 1. In the table, A is a conventional method in which the symmetric tire is mounted on the front and rear wheels, B is a mounting method in which the asymmetric structure tire is mounted on both the front and rear wheels so that the inner rigidity is increased, and C is the front and rear wheels of the asymmetric structure tire. When both are mounted so that the outside rigidity is increased, D is the asymmetric structure tire when the front wheel is mounted so that the outside rigidity is large and the rear wheel is mounted such that the inside rigidity is large. This is a mounting method according to the present invention in which the rigidity of the rear wheel is large and the rear wheel is mounted so that the rigidity on the outside is large. Incidentally, the evaluation of the test results is indicated by an index with the case of the conventional method of mounting the symmetrical tire on the front and rear wheels as 100, and the larger the numerical value in the table, the larger the value.
Good.

[0012]

[Table 1]

From the above test results, it can be seen that the lap time and feeling are improved on average in the case of using the mounting method of the present invention as compared with other mounting methods.

[0014]

According to the present invention, when the asymmetrical structure tire is mounted on the vehicle as described above, the front wheel is provided with an inner rigidity greater than that of the vehicle, and the rear wheel is provided with the same structure tire on the outer side in the opposite direction. It is a method of mounting so that the rigid tire of the tire becomes larger, averaging the exercise performance of the front and rear wheels, improving feeling, lap time and extremely reducing the tendency of understeer compared to various conventional mounting methods,
It has a remarkable effect that can improve cornering performance, and is expected to be effective as a tire mounting method for vehicles, especially high-speed racing vehicles.

[Brief description of the drawings]

FIG. 1 is a view showing a mounted state of a front wheel tire when traveling straight.

FIG. 2 is a diagram showing a mounted state of a rear wheel tire when traveling straight.

[Explanation of symbols]

 (1) Asymmetric structure tire

Claims (1)

(57) [Claims] In mounting a tire having an asymmetric structure having a greater rigidity on one side than a side on the other side in a tire circumferential direction in a vehicle, a front wheel side has an inner rigidity with respect to the vehicle. The method of mounting a vehicle with an asymmetrically structured tire is characterized in that the tire having the same structure is mounted on the rear wheel side so as to increase the rigidity of the outside on the rear wheel side.