JP2001018608A - Pneumatic tire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To greatly reduce passenger compartment noise by effectively controlling resonance in a tire. SOLUTION: One or plural air disturbance bodies 10 three dimensionally formed from non-venting material and having at least one air screen surface 11 are rollably housed in a space 7 in a tire T mounted on a wheel rim R. The air disturbance bodies 10 is formed from a heat resistant material with a melting point greater than or equal to 100 deg.C and its total weight less than or equal to 50 g.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pneumatic tire which suppresses resonance in a cavity in the tire.

[0002]

2. Description of the Related Art Conventionally, in order to reduce the resonance sound of air in a cavity in a tire, which is one of the causes of generation of a vehicle interior sound, a tire inner peripheral surface or a rim is conventionally used. Measures have been taken such as fixing the porous sound absorbing material by an adhesive means or the like.

However, if the sound absorbing material is fixed to the tire or the rim by an adhesive means or the like, heat is generated during the tire load operation, the adhesive layer is thermally degraded, and the sound absorbing material is easily peeled off. When peeling occurs, there is a problem that the balance of the tire is deteriorated and the steering stability is reduced. In addition, since the operation of bonding the sound absorbing material into the tire is required, the number of steps required for assembling the rim increases, and there is a problem that the workability is reduced.

[0004] Further, it has been proposed to insert and arrange a porous sound-absorbing material such as a fiber molded article or a foam molded article in a cavity in a tire so as to be freely movable (for example,
In this case, the in-vehicle sound such as road noise is reduced by absorbing the resonance sound in the cavity with a porous sound absorbing material, and the resonance itself is suppressed. It is not satisfactory in terms of point.

The present invention has been made in view of the above, and an object of the present invention is to provide a pneumatic tire capable of effectively suppressing the resonance of the cavity in the tire and enhancing the effect of reducing the sound in the vehicle.

[0006]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention is directed to a tire mounted on a rim of a wheel, wherein the cavity in the tire is surrounded by an inner peripheral surface of the tire and the rim. Further, one or more air turbulators formed three-dimensionally from a non-breathable material and having at least one air shielding surface are housed so as to be able to roll freely.

[0007] According to this pneumatic tire, when the vehicle is running, the air-turbulence body having at least one air-shielding surface accommodated in the cavity in the tire is irregularly rolled in the cavity as the tire rotates. By moving and moving, the air in the tire is disturbed and a turbulent flow is generated, so that the resonance of the air in the tire, which is one of the causes of the sound in the vehicle, can be effectively suppressed.

The air disrupter is preferably made of a heat-resistant material having a melting point of 100 ° C. or higher. As a result, even if the temperature inside the tire becomes a high temperature close to 100 ° C.,
Withstand its use well.

[0009] It is preferable that the total weight of the air disrupter housed in the cavity in the tire is 50 g or less. Thereby, resonance can be effectively suppressed without impairing the steering stability not only in the case of one air conditioner but also in the case of accommodating a plurality of air disturbance bodies.

In the pneumatic tire of the present invention, instead of the above-described air disrupter, an opening formed in a hollow space in the tire surrounded by the tire inner peripheral surface and the rim and having a hollow three-dimensional shape is provided in the peripheral wall. Thus, one or a plurality of hollow bodies formed so as to allow air to flow therethrough can be housed so as to freely roll.

[0011] In this pneumatic tire also, when the vehicle is running, the hollow body accommodated in the cavity of the tire rolls irregularly in the cavity as the tire rotates, so that the air in the tire is released. While circulating inside and outside the hollow body through an opening in the peripheral wall and disturbing the air in the tire to generate a turbulent flow, it also has a sound reducing effect inside the hollow body and is one of the causes of vehicle interior noise. The resonance of the air in the tire can be effectively suppressed.

It is particularly preferable that a large number of the openings are formed in a scattered manner over the entire circumference of the hollow body, whereby the resonance of the air in the tire and the noise reduction can be more effectively achieved.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described based on embodiments shown in the drawings.

FIG. 1 is a cross-sectional view in the tire width direction of a main part of a pneumatic tire (T) according to a first embodiment of the present invention.
4 is a perspective view exemplifying an air disturbance body for resonance suppression accommodated in a tire cavity.

[0015] The pneumatic tire (T) of the illustrated embodiment is shown.
Shows a case of a radial tire, a bead portion (2) on both sides having a bead core (1), a sidewall portion (3) extending radially outward from the bead portion (2), and the sidewall portion (3). ), And a carcass (5) which is folded and locked and supported at both ends by a bead core (1) along the inner periphery thereof, and a tread portion (4) and a carcass (4). And 5) a reinforcing belt layer (6). Since the reinforcing structure is the same as that of a general radial tire, a detailed description is omitted.

The tire (T) is mounted on a rim (R) of a wheel as shown in FIG. A cavity (7) in the tire surrounded by the inner peripheral surface of the tire (T) and the rim (R)
Has an air shielding surface (1) formed by at least one flat surface.
One or more air disrupters having (1) (10)
Are accommodated so as to freely roll in the cavity (7).

The air disrupter (10) is formed in a three-dimensional shape that can be easily rolled using a non-permeable material. For example, in the case of the air-turbulent body (10) of the embodiment of FIGS. 1 and 2, three thin sheet-shaped disks (12) made of the above-described non-permeable material are intersected at right angles to each other, and Are combined in a three-dimensional direction (three directions) intersecting at right angles to the two intersecting axes to be integrally formed, and have a spherical shape that easily rolls as a whole. In this case, a large number of air shielding surfaces (11) formed by the front and back surfaces of the three disks (12) intersect in a triangular pyramid on the outer periphery.

In the case of the air-turbulence body (10) of FIG. 3, a gyroscope (10) is provided in which a disk-shaped top (14) is rotatably supported inside a ring-shaped support member (13). The top and the back of the top (14) function as an air shielding surface (11).

In the case of the air disrupter (10) in FIG.
A large number of thin plates (15) are crossed on the same axis and assembled in an easily rolling impeller shape, and the thin plates (15) form a large number of air shielding surfaces (11).

In addition to the above, the air disrupter can be formed in various three-dimensional shapes having at least one flat air shielding surface and easy to roll.
In order to allow rolling in the cavity (7) of the tire (T),
It is formed so that its diameter and length do not exceed 100 mm.

As the non-breathable material, various non-breathable materials such as paper or synthetic resin such as nylon, polyethylene, polypropylene and polyurethane or a laminate thereof can be used. From the viewpoint of properties, a synthetic resin material is particularly preferably used.

Further, since the temperature of the air in the tires may reach a maximum of 100 ° C. when the vehicle is running, the air permeable material of the air disruptor (10) has a heat resistance having a melting point of 100 ° C. or more. A material made of such a material is particularly preferable from the viewpoint of durability.

The greater the number of the above-mentioned air turbulators (10), the more effective the suppression of resonance. However, if the total weight is large, vibration occurs during running of the vehicle, which may impair steering stability. When a plurality of air disrupters (10) are accommodated in the cavity (7) in the tire, the total weight thereof is 5
It is good to be 0 g or less. However, when the number increases,
Since the workability at the time of assembling the rim is deteriorated, it is practically preferable that the number is 2 or less per 10 liters of the volume of the cavity (7).

According to the pneumatic tire (T), when the vehicle is running, the air disturbing body (10) having at least one air shielding surface (11) housed in the cavity (7) in the tire can be used as the tire. Rolling and moving irregularly in the cavity along with the rotation of the tire, the air in the tire cavity is disturbed and turbulence is generated, and the resonance of the air in the tire, which is one of the causes of vehicle interior noise, is reduced. It can be suppressed effectively.

FIG. 5 shows an embodiment (a) of the present invention in which an air disturbing body (10) is accommodated in four tires of a domestic passenger car having a displacement of 2000 cc and a conventional tire in which no sound absorbing material is accommodated in the tire. For the comparative example (b) of the tire and the comparative example (c) in which the ball-shaped sound absorbing material is housed in the tire, the results of measuring the noise (sound pressure) at the front window side when traveling at a speed of 60 km / h are shown. I have.

In the embodiment (a), two air-turbulence bodies (10) of the form shown in FIG. 2 in which three discs each having a radius of 30 mm are combined are accommodated in a cavity in a tire. Comparative example (c) contained a ball-shaped sound absorbing material made of polyurethane foam.

The tires used in the test were tires of the same structure (same tread pattern) with two steel belts having a tire size of 215 / 45ZR17, and a specified air pressure and a specified load were applied.

As is apparent from FIG. 5, the sound pressure around 250 Hz is the lowest in the embodiment in which the air-turbulent body of the present invention is housed, and the present invention is useful for suppressing the resonance of the tire cavity. As described above, it is effective to house the air disrupter (10).

FIG. 6 shows that in the second embodiment of the present invention, instead of the above-mentioned air disrupter (10), it is housed so as to freely roll in a cavity in a tire surrounded by a tire inner peripheral surface and a rim. 1 illustrates a hollow body (20) for use in air disturbance.

The hollow body (20) is made of a relatively impermeable material, such as nylon, polyethylene, polypropylene, polyurethane and other various synthetic resin materials, which are mainly the same as those of the first embodiment of the present invention. It is formed in a round hollow hollow shape such as a substantially spherical shape which is thin and lightweight and has an appropriate shape-retaining property, and is formed so that air can freely flow through an opening (22) formed in a peripheral wall (21) thereof.

The size and number of the apertures (22) can be set as appropriate. However, from the viewpoint of suppression of resonance due to air flow and sound reduction effect, the diameter is, for example, 2 to 15 mm, preferably 5 to 10 m.
As shown in the figure, it is desirable to form a large number of apertures (22) at m at substantially equal intervals over the entire circumference.
The thickness of the peripheral wall (21) is preferably as thin as possible within a range that does not impair the shape-retaining strength in order to reduce the weight, and is usually formed to be 1.0 mm or less.

Further, the hollow body (20)
A material made of a heat-resistant material having a melting point of 100 ° C. or more is preferable from the viewpoint of durability in use. The number of the tires to be accommodated in the cavity is preferably as large as possible in terms of the effect of suppressing resonance. However, from the viewpoint of steering stability, the total weight is preferably set to 50 g or less. From the point of view, it is preferable to set the number to two or less per 10 liters of cavity volume.

The hollow three-dimensional shape of the hollow body (20) is not limited to a true sphere, but may be embodied in various forms such as an elliptical sphere, an oval, and a round rod. However, in practice, it is better to make it approximately spherical with good rolling properties,
Further, the maximum diameter and the length are set to 100 mm or less.

In a pneumatic tire in which one or a plurality of the hollow bodies (20) are housed in a cavity in the tire, the hollow body (20) is not fitted in the cavity as the tire rotates during running of the vehicle. By rolling regularly, the air in the tire is turbulent by disturbing the air in the tire while flowing in and out of the hollow body (20) through the opening (22) provided in the peripheral wall (21). Together with the hollow body (20)
The sound reduction effect is achieved inside the vehicle, and the resonance of air in the tire, which is one of the causes of vehicle interior noise, can be effectively suppressed.

[0035]

As described above, according to the first pneumatic tire of the present invention, the air-turbulent body having at least one air-shielding surface is housed in the cavity in the tire so as to be freely movable. As a result, resonance can be efficiently suppressed by the turbulence of air in the tire cavity, and vehicle interior noise due to cavity resonance can be effectively reduced.

Further, according to the second pneumatic tire of the present invention, the hollow body which communicates with the inside and the outside by the opening housed in the cavity in the tire allows the air to be disturbed in the tire and the inside of the hollow body to be disturbed. , The resonance can be effectively suppressed, and the noise in the vehicle can be effectively prevented.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view in a tire width direction of a main part showing one embodiment of the present invention.

FIG. 2 is an enlarged perspective view showing an example of an air disrupter housed in a cavity in a tire.

FIG. 3 is an enlarged perspective view showing another example of an air disrupter housed in a cavity in a tire.

FIG. 4 is an enlarged perspective view showing another example of the air disrupter housed in the cavity in the tire.

FIG. 5 is a graph showing a result of measuring sound pressure by an actual vehicle.

FIG. 6 is a perspective view showing an example of a hollow body housed in a cavity in a tire according to a second embodiment of the present invention.

[Explanation of symbols]

 (T) Tire (R) Rim (1) Bead core (2) Bead part (3) Side wall part (4) Tread part (5) Carcass (6) Belt layer (7) Cavity (10) Air disrupter (11) Air shielding surface (12) Disk (13) Support member (14) Top (15) Thin plate (20) Hollow body (21) Perimeter wall (22) Opening

Claims (5)

[Claims] 1. A tire mounted on a rim of a wheel, wherein the tire is formed in a three-dimensional shape with a non-breathable material in a cavity in the tire surrounded by an inner peripheral surface of the tire and the rim, and has at least one surface. A pneumatic tire characterized in that one or a plurality of air disrupters having an air shielding surface are housed so as to be able to roll freely. 2. The pneumatic tire according to claim 1, wherein the air disrupter is made of a heat-resistant material having a melting point of 100 ° C. or higher. 3. The pneumatic tire according to claim 1, wherein the total weight of the air-turbulent body accommodated in the tire cavity is 50 g or less. 4. A tire mounted on a rim of a wheel, wherein a hollow space in the tire surrounded by the inner peripheral surface of the tire and the rim has a hollow three-dimensional shape and an air flow through an opening formed in a peripheral wall. A pneumatic tire characterized in that one or a plurality of freely formed hollow bodies are housed so as to freely roll. 5. The pneumatic tire according to claim 4, wherein a large number of said openings are formed in a scattered manner over the entire circumference of said hollow body.