JPH09188103A - Vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance the anti-hydroplaning performance in the road surface on which water films are formed by removing the water films existing ahead of a vehicle advancing in the direction of travel. SOLUTION: In a vehicle, on the car body 2 of which pneumatic tires 3 are loaded, an air blowing tool 5 with an air nozzle 4 for injecting air toward the road surface on which the pneumatic tires 3 are in contact and toward the tire contact road surface S ahead of the vehicle advancing in the direction of travel, for the purpose of preventing hydroplaning, is provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle in which a pneumatic tire is mounted on a vehicle body, in which a water film formed on a road surface located in front of the pneumatic tire can be eliminated to reduce the occurrence of hydroplaning. .

[0002]

2. Description of the Related Art In a vehicle equipped with pneumatic tires and traveling on a road surface, when a water film is formed in front of the tire due to rainwater, for example, this water film is It is guided to the tread groove of the tire due to the weight and the like and is discharged outside the tire. However, if there is a large amount of water on the road surface that exceeds the drainage capacity of the tire,
A water film remains on the ground contact surface of the tire, and the tire floats due to this water film, which causes so-called hydroplaning that impairs traction, braking, and maneuverability of the tire.

Such a phenomenon mainly occurs in the front wheels that directly enter the water film, and in the rear wheels, since the front wheels remove the water film, the water film layer passes through a thin road surface, so that it is relatively rare. .

Hydroplaning is caused by an increase in speed, and in a tire having the same specifications, the thicker the water film, the lower the critical speed at which hydroplaning occurs. For example, when the water film is 10 mm, the critical velocity when the water film is 5 mm is reduced by about 10 to 15% in the linear hydroplaning and is reduced by about 25% in the lateral hydroplaning. Here, the lateral hydroplaning means the speed at which the maximum lateral G occurs.

By the way, the tire size is 195/55
A test for determining the critical speed at which hydroplaning occurs at a water film of 5 mm and 10 mm, while mounting on the front wheel of a 1600 cc class FF vehicle with a tire of R15 and the tread pattern shown in FIG. Was carried out. The test results are shown in Table 1.

[0006]

[Table 1]

The critical rate of occurrence of hydroplaning when the water film thickness is 10 mm is approximately equivalent to the critical rate of occurrence of hydroplaning when the tread surface of the tire is worn by 30% when the water film thickness is 5 mm. In other words, if the thickness of the water film on the road surface can be reduced, for example, from 10 mm to 5 mm, even if the tire is in the 30% wear state, it can maintain the same hydroplaning resistance as that of a new tire. Become.

As a result of repeated studies by the inventor to solve the above problems, a) the hydroplaning phenomenon is in the vicinity of the tire equator where the ground contact pressure is highest on the tread surface of the tire. (B) It is possible to change the pattern on the tire side, but if the hydroplaning resistance is improved by increasing drainage such as by increasing the tread groove, the wear resistance and uneven wear resistance of the tire will be improved. It is a sacrifice, and it is difficult to support the improvement of hydroplaning resistance and the improvement of tire durability. I got to know

Therefore, the inventor has further studied, and by injecting air toward the road surface in front of the tire, at least with respect to the ground contact surface of the tire, the water film existing in the front in the traveling direction is eliminated, and hydroplaning is performed. They have found that the phenomenon can be reduced.

An object of the present invention is to provide a vehicle capable of removing a water film formed on a road surface located in front of a pneumatic tire and reducing the occurrence of hydroplaning.

[0011]

According to the present invention, in a vehicle having a pneumatic tire mounted on a vehicle body, hydroplaning is performed forward of a road surface on which the pneumatic tire is in contact with the vehicle body and a tire contact surface in a vehicle traveling direction. It is a vehicle provided with an air blower having an air outlet for injecting preventive air.

By injecting air toward the road surface in this manner, the water film in front of the tire ground contact surface is removed and the critical speed at which hydroplaning occurs is increased, so that high speed running on wet road surface becomes possible. In addition, it is possible to compensate for the deterioration of the hydroplaning resistance resulting from the wear of the tire tread surface.

The height H of the air outlet is 30
The distance L in the vehicle traveling direction from the front end point of the tire contact surface to the vehicle traveling direction is preferably more than 0 mm and 800 mm or less while being 0 mm or less and a height in consideration of road obstacles.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to the drawings by taking a case where a vehicle is a passenger car as an example.

1 to 6, a vehicle 1 has a vehicle body 2 on which pneumatic tires 3 for traveling are mounted. In the present example, the pneumatic tire 3 includes a pair of steering front wheels 3A and 3A arranged in front of the vehicle body 2 and a pair of driving rear wheels 3B and 3B arranged behind the vehicle body 2. The front tires 3A and the rear tires 3B are arranged substantially linearly before and after the vehicle in the traveling direction.

Further, the vehicle body 2 is provided with an air blower 5 having an air outlet 4 for injecting air forward of the road surface R on which the pneumatic tire 3 comes into contact with the ground and the tire ground contact surface S forward of the vehicle. ing.

As shown in FIGS. 5 and 6, the pneumatic tire 3 has four vertical grooves 12 extending in the tire circumferential direction on the tread surface 11 in this embodiment, and intersects the vertical grooves 12 and the tire equator C.
It has a bilaterally symmetrical pattern in which a tread groove 14 formed of a lateral groove 13 extending from the vicinity toward the tread edge E is formed. Therefore, when the pneumatic tire 3 contacts the road surface R, the water film present on the contact surface S is guided to the vertical groove 12 and discharged rearward in the traveling direction as the tire rotates.

Further, in this embodiment, the lateral groove 13 is formed in an arc shape in which the inclination angle with respect to the tire equator C gradually increases from the tire equator C toward the tread edge E, whereby the water film existing on the ground contact surface S is formed. The water can be efficiently drained not only to the rear but also to both sides, improving drainage efficiency.

In the pneumatic tire 3, the tread portion 15 forming the tread surface 11 to the sidewall portion 1 is formed.
The carcass 19 is folded back around the bead core 18 of the bead portion 17 and the belt layer 20 is provided outside the carcass 19 and inside the tread portion 15.

In this example, the air blower 5 is formed by connecting an air intake port 6 opening on the front surface of the vehicle body and the air outlet 4 with an air blow pipe 7.

In this example, the air outlet 4 is provided only on the front wheel 3A in which the hydroplaning phenomenon appears remarkably. It should be noted that the rear tire 3B does not hinder the provision of the same air outlet as the front tire 3A at the front in the traveling direction.

As shown in FIG. 2, the air intakes 6 are arranged on both sides of a radiator arranged on the front surface of the vehicle body 2, and the cross-sectional area W1 of the air intakes 6 is at least as shown in FIG. It is larger than 50 cm ² and is 1.5 times or more of the cross-sectional area W2 of the air outlet 4. Further, the air supply pipe 7 is formed so that the cross-sectional area of the pipe gradually decreases from the air intake port 6 toward the air outlet port 4 without interposing a step.

Further, in this embodiment, a flow rate adjusting valve 9 capable of adjusting the amount of air injected from the air outlet 4 and discharging surplus air is interposed in the air supply pipe 7.

The air outlet 4 is fixed to the bearing portion 23 of the suspension 22 which pivotally supports the front wheel 3A as shown in FIG. 4 can be independent of the movement of the vehicle body 2, the air outlet 4 can follow the turning of the front wheel 3A by the steering wheel operation, and the air outlet 4 can always be positioned in front of the contact surface S of the front wheel tire 3A. I can.
In this case, a flexible part is interposed in a part of the air supply pipe 7.

The air outlet 4 preferably has a height H from the road surface R of 300 mm or less and, in consideration of a road obstacle, for example, 30 mm or more. Further, the air outlet 4 has a tread pattern that is bilaterally symmetric, so that the distance L between the front extension line of the tire equator C and the front end point SF of the tire ground contact surface S is more than 0 and 8
It is preferable that the thickness is 00 mm or less. In addition, it is not preferable that the displacement of the air outlet 4 with respect to the traveling direction of the vehicle 1 laterally exceeds the ground contact width, which is the axial width of the ground contact surface S of the tire.

The air outlet 4 may be opened with the direction perpendicular to the road surface R as the blowing direction line as shown in FIG. 1, and as shown in FIG. 8, the blowing direction line is directed downward. It is also possible to incline so as to incline backward in the traveling direction.

Here, the ground contact surface S refers to a ground contact area in which the pneumatic tire 1 is mounted on a reference rim and comes into contact with the road surface R when a normal internal pressure and a specified maximum load of the tire are applied.

The height H of the air outlet 4 from the road surface R is 3
If the distance L is greater than 00 mm and the distance L is greater than 800 mm, the effect of eliminating the water film on the road surface R is reduced.

The sectional area W1 of the air intake port 6 is 50 cm.
^If it is ² or less, the amount of air injected from the air outlet 4 is insufficient, and if the cross-sectional area W1 of the air inlet 6 is less than 1.5 times the cross-sectional area W2 of the air outlet 4, the wind speed of the air to be injected is obtained. This makes it difficult to remove the water film on the road surface R in either case.

In the case where the air intake port 6 is provided on the front surface in the traveling direction of the vehicle body 2 as in this example, the air is taken in by the traveling of the vehicle 1 and the air is ejected from the air outlet port 4 Therefore, it is possible to save energy without requiring power for injecting air.

In addition, in the above structure, the injection amount of air increases as the traveling speed increases,
The effect of removing the water film is in harmony with this hydroplaning phenomenon in which hydroplaning is likely to occur as the traveling speed increases, and it is possible to efficiently suppress the occurrence of hydroflaning during high-speed traveling.

Further, the air blower may be formed so as to eject hot air with a heater or the like for heating the air flowing through the air blower interposed. By interposing the heater in this way, it is possible to more efficiently remove the water film in the winter or cold regions.

7 and 8 show another embodiment of the air blower. In FIG. 7, the air blower 5A is the engine G.
After the muffler 26 muffles the exhaust gas generated by the muffler 26, it branches from the switching valve 27 and the air outlet 4A
It is formed to lead to.

Further, in FIG. 8, an air blower 5B
The air intake port 6B is provided in the bonnet in which the engine of the vehicle body is housed, so that the engine is cooled and the heated air is sucked by the blower 29 and the air outlet port 4B is used.
To the road surface R in front of the tire ground contact surface S. In this way, the air blower can be modified into various forms.

[0035]

Example A state in which a tire size is 195/55 R15, and a pneumatic tire having a pattern shown in FIG. 6 is attached to a 6 1/2 × 15 rim and an internal pressure of 2.2 kgf / cm ² is applied. Then, the test was conducted by mounting the FF vehicle of 1600 cc class on all wheels and running the vehicle on a test road having a water film formed on the road surface (Examples 1 to 3). The test is also performed on a vehicle having a conventional configuration without an air supply device (conventional example) and a vehicle having an air outlet at a position outside the regulation range in claim 2 of the present application (reference examples 1 to 5). The performance was compared.

The test method is as follows. 1) Straight Hydroplaning Test A water film with a water depth h1 of 10 mm was formed on a straight test road, and a deceleration meter s1 was added to the test vehicle 1A as shown in FIG.
And the fifth wheel 30 for vehicle speed measurement are installed and the front wheel 3
The relative relationship between the vehicle speed v1 when the lock braking is applied only to A and the deceleration gr at that time is measured as shown in FIG. 10, and the critical speed when hydroplaning occurs is determined. The higher the value, the better.

2) Lateral Hydroplaning Test As shown in FIG. 11, a water film having a water depth h2 of 5 mm was formed over a length of 20 m on a curved test road having a radius of 100 m.
The lateral acceleration gs s2 is further attached to the front part of the test vehicle 1B, and the lateral acceleration gs and the length 5 immediately before entering the water film path w2 are set.
The relative relationship between the m and the vehicle speed v2 on the dry road f was measured as shown in FIG. 12, and the maximum value of the lateral acceleration gs, that is, the critical vehicle speed when the lateral hydroplaning occurred was determined. The higher the value, the better. Table 2 shows the installation conditions and test results of the air blower.

[0038]

[Table 2]

As a result of the test, it was confirmed that the products of Examples 1 to 3 had improved linear hydroplaning resistance and lateral hydroplaning resistance as compared with the conventional example. It was also confirmed that the linear and lateral hydroplaning resistance of each of the examples was further enhanced by regulating the height and distance of the air outlet compared to the reference example.

[0040]

As described above, the vehicle of the present invention has
Since the gist is to arrange an air blower for injecting air toward the front in the traveling direction of the tire ground contact surface, the water film formed on the road surface can be removed only in the front portion of the tire traveling direction, The water film generated by rainfall etc. can be efficiently removed without changing the tire pattern, so that the hydroplaning resistance is improved, and the hydroplaning resistance is deteriorated due to abrasion of the tread surface. However, since the thickness of the water film on the road surface immediately before the tire touches the ground is reduced, substantial hydroplaning resistance can be maintained, which is also useful for improving tire durability.

[Brief description of the drawings]

FIG. 1 is a side view showing an example of an embodiment of the present invention.

FIG. 2 is a front view thereof.

FIG. 3 is a perspective view showing an example of attachment of an air blower.

FIG. 4 is a diagram showing a relationship in cross-sectional area between the air intake port and the air outlet port.

FIG. 5 is a cross-sectional view showing an example of a tire mounted on a vehicle body.

FIG. 6 is a developed plan view showing the tread pattern.

FIG. 7 is a plan view showing another form of the air blower.

FIG. 8 is a side view showing still another form of the air blower.

FIG. 9 is a front view showing a method of a linear hydroplaning test.

FIG. 10 is a graph showing an example of the measurement.

FIG. 11 is a plan view showing a method of a lateral hydroplaning test.

FIG. 12 is a graph showing an example of the measurement.

[Explanation of symbols]

 2 Car body 3 Pneumatic tire 4 Air outlet 5 Air blower H Height of air outlet H Height of air outlet L Distance of air outlet from tire contact surface front end point R Road surface S Tire contact surface SF Tire contact surface Front end point of

Claims (2)

[Claims] 1. A vehicle in which a pneumatic tire is mounted on a vehicle body, and an air outlet for injecting air for preventing hydroplaning toward a front side of a road surface on which the pneumatic tire is in contact with the vehicle body and a tire contact surface to a front side in a vehicle traveling direction A vehicle in which an air blower having the above is arranged. 2. The air outlet has a height H of 300 mm or less and a height of not less than a road obstacle, and
2. The vehicle according to claim 1, wherein a distance L in the vehicle traveling direction between a front end point of the tire contact surface and the vehicle traveling direction is more than 0 and 800 mm or less.