JP2001187507A - Assembly of pneumatic tire and rim - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce road noises. SOLUTION: This assembly 1 of a tire and a rim has a tire inner cavity 4 in the surrounding of the rim, formed by mounting the pneumatic tire 2 on the rim 3. A rising part 5 made of a flexible sheet piece whose one end 5a is fixed to the outer circumferential surface of the rim 3 and rising in the tire radial direction by the centrifugal force used by the rotation of the assembly 1 to block the tire inner cavity 4 is installed. The rising part 5 is formed so that the height Ha in the tire radial direction is 90-130% the inner cavity height H, and the width Wa in the tire axial direction is 58-75% the tire inner cavity maximum width.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an assembly of a rim and a pneumatic tire, which can reduce road noise during traveling while improving rim assembly.

[0002]

2. Description of the Related Art In recent years,
There is a demand for lower noise and quieter vehicles. There are various types of noise generated by tires. Among them, when traveling on rough roads, a so-called road noise that generates a “go” sound in a frequency range of 50 to 400 Hz is transmitted to the inside of the vehicle and is generated in the vehicle interior. The muffled sound gives the occupants a discomfort. Such a road noise is generated when the tire is mounted on the rim, and the tire bore formed around the rim and formed of a cavity surrounded by the tire and the rim forms an air column tube, and the air undergoes resonance vibration (cavity resonance). It is known that what you do has a big impact.

The present invention has been devised in view of such a problem, and provides a rising portion on the outer peripheral surface of the rim, which rises in the tire radial direction from the outer peripheral surface of the rim by centrifugal force and blocks the tire bore. It is another object of the present invention to provide an assembly of a pneumatic tire and a rim that can reduce road noise without impairing the rim assemblability of the tire based on limiting the shape and the like of the rising portion.

[0004]

The invention according to claim 1 of the present invention is an assembly of a rim and a pneumatic tire in which a tire cavity is formed around the rim by mounting the pneumatic tire on the rim. A rising portion which is formed of a flexible sheet piece having one end fixed to the outer peripheral surface of the rim and which rises in the tire radial direction from the outer peripheral surface of the rim by centrifugal force accompanying rotation of the assembly to block the tire lumen. The rising portion has a height Ha in the radial direction of the tire of 90 to 130% of the height H of the tire lumen, and the width Wa of the rising portion in the axial direction of the tire is 58 to the maximum width of the tire lumen.
It is characterized by being 75%.

[0005] Here, the tire lumen height H and the tire lumen maximum width W are in a normal state with no load when the assembly is filled with a normal internal pressure. The normal internal pressure is the air pressure specified for each tire in the standard system including the standard on which the tire is based. For JATMA, the maximum air pressure is used, and for TRA, the table "TIRE LOAD LIMITSAT"
The maximum value described in "VARIOUS COLD INFLATION PRESSURES" is "INFLATION PRESSURE" in the case of ETRTO. However, when the tire is for a passenger car, the internal pressure is set to 200 kPa in consideration of the most frequently used internal pressure in practical use.

According to a second aspect of the present invention, the rising portion has a substantially rectangular shape, and has, at the one end side, a fixing portion having substantially the same width as the rim bottom and fixed to the rim bottom;
The pneumatic tire and rim assembly according to claim 1, further comprising a non-fixed portion that protrudes from at least one of the width directions from the rim bottom portion and is not fixed to the outer peripheral surface of the rim.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view of an assembly of a pneumatic tire and a rim of the present embodiment (hereinafter, may be simply referred to as an “assembly”). FIG. 2 is a cross-sectional view along the tire equatorial plane. Shows perspective views of main parts of the rim. In the figure, an assembly 1 includes a pneumatic tire (hereinafter, referred to as a pneumatic tire).
Sometimes simply referred to as a "tire." 2) is mounted on the rim 3 to form a tire cavity 4 around the rim 3 around the tire 2 and the rim 3.

As shown in FIG. 1, the rim 3 of the present embodiment
Is formed with a rim bottom portion (also referred to as a "well") 3a having a reduced outer diameter in order to drop the bead portion 2a of the tire 2 when assembling the rim of the tire 2. The tire 2 of the present embodiment is, for example, a radial tire for a passenger car in which noise performance tends to be a problem, and the bead portion 2a
The rim is assembled in close contact with the flange 3b of
An airtight tire cavity 4 is formed with the rim 3 by forming a tubeless structure in which an inner surface facing the tire cavity 4 is provided with a so-called inner liner rubber that does not easily transmit air.

A rising portion 5 is provided on an outer peripheral surface of the rim 3 in a tire radial direction. The rising part 5
Fixes one end 5a to the outer peripheral surface of the rim 3 and
As shown in FIGS. 1 to 3, the inner space of the tire is formed by a flexible and substantially rectangular sheet piece, which rises in the tire radial direction from the outer peripheral surface of the rim 3 by the centrifugal force accompanying the rotation of the assembly 1. Block 4 Thereby, the rising portion 5 can suppress the cavity resonance by blocking the air flow in the tire lumen 4 and can reduce road noise. When no centrifugal force is applied, the rising portion 5 is configured to fall on the outer peripheral surface of the rim 3 as shown in FIG.

The rising portion 5 is preferably made of a material which does not transmit air and which can be appropriately expanded and contracted in consideration of the rim assembling property, for example, a vulcanized rubber, among which natural rubber (NR), isoprene rubber (IR), butadiene rubber (BR), styrene butadiene rubber (SBR), nitrile rubber (NBR),
Diene rubbers such as chloroprene rubber (CR) are preferred. However, various materials other than rubber, such as resin sheets and paper, can be used as long as they prevent air permeation. When the rising portion 5 is formed of rubber, if the thickness is excessively large, the tire weight tends to be heavy or the rim assembling property tends to be deteriorated. There is a problem. From such a viewpoint, the rising portion 5
Has a thickness of, for example, 0.5 to 3 mm, more preferably 0.5 to 3 mm.
２2 mm, more preferably 1-2 mm.

As shown in FIGS. 1 and 3, the rising portion 5 has a rim bottom 3a at one end 5a fixed to the rim 3. As shown in FIG.
A fixing portion 6 having a width substantially equal to or less than that of the rim 3a and being fixed to the outer peripheral surface of the rim bottom 3a; An example is shown in which non-fixed portions 7 are not fixed to the surface. The fixing portion 6 is fixed to the rim bottom 3a using an appropriate fixing means such as an adhesive, a screw, a rivet, or the like. In addition, the non-fixed portion 7 is cut out along the outer peripheral surface of the rim 3 in the rising state of the rising portion 5 to facilitate the rising of the rising portion 5. The width of the rim bottom 3a is, for example, the bead portion 2a
Width RW in which a small diameter portion capable of dropping is substantially continuous
And The rim bottom 3a may be inclined at a small angle with respect to the tire axial line.

The rising portion 5 has a tire lumen height H in which the height Ha in the tire radial direction is the maximum height of the tire lumen 4.
And the width Wa of the rising portion 5 in the tire axial direction is 58 to 75% of the tire lumen maximum width W. The height Ha of the rising portion 7 is less than 90% of the tire lumen height H, and the width Wa is the tire lumen maximum width W.
When it is less than 58%, the effect of shielding the tire lumen 4 tends to decrease. Conversely, when the width Wa of the rising portion exceeds 75% of the tire lumen maximum width W, the widthwise edge 5e of the rising portion 5 tends to be located on the rim bead seat 3c on which the bead portion 2a of the tire sits. Strongly, the rim assemblability tends to be significantly deteriorated, for example, the rising portion 5 is easily sandwiched between the bead portion 2a of the tire 2 and the bead seat 3c. Further, even if the height Ha of the rising portion 5 exceeds 130% of the tire lumen height H, the length becomes excessive and the road noise reduction effect reaches a plateau.

From such a viewpoint, in order to effectively balance the rim assembling property and the road noise reduction effect, the height Ha of the rising portion 5 is set at 11 of the tire cavity height H.
It is particularly desirable that the width Wa be 0 to 130% and the width Wa be 65 to 75% of the maximum width W of the tire lumen. Also, the cross-sectional area As in the cross section including the tire axis of the tire lumen 4 (normal state)
And the ratio of the surface area Ab of the rising portion 5 (Ab / As)
Is desirably set to, for example, 40% or more, more preferably 50% or more, and further preferably 70% or more, in that the road noise can be more effectively reduced.

The rising portion 5 of this type has a larger shape, so that the shielding efficiency of the tire lumen 4 is increased and the effect of reducing road noise is exhibited. Become. In the rising portion 5 of the present example, the fixed portion 6 and the non-fixed portion 7 are provided on one end side 5a, so that the width Wa of the rising portion is increased as shown in FIG. While securing the area, when the rim is assembled, the side of the rising portion 5 on each non-fixed portion 7 is folded toward the rim bottom 3a, so that the rising portion 5 can be easily stored in the rim bottom 3a. Therefore, it is particularly favorable in that deterioration of the rim assemblage can be reliably prevented.

In this embodiment, the rising portion 5
Although only one is provided in the tire cavity 4 as shown in FIG. 2, a plurality of tires may be arranged at intervals in the tire circumferential direction. By providing a plurality of rising portions 5, resonance in the tire lumen 4 can be more effectively suppressed, which helps to significantly reduce road noise during running, but relatively reduces rim assemblability.

[0016]

EXAMPLES Tires (195 / 65R15) and rims (15
× 6JJ), an assembly of a pneumatic tire and a rim was experimentally manufactured, and a rising portion (1 mm thick) of the present invention was provided to evaluate noise performance and the like. For comparison, an assembly (comparative example) other than the present invention, such as an assembly having no rising portion, was also prototyped and tested. The height H of the tire bore was 116 mm, and the maximum width W of the tire bore was 190 mm. The content of the test is as follows.

(Noise test) A rim assembly with an internal pressure of 200 KPa was mounted on a 2000cc FR car manufactured in Japan, and the speed of the road noise measurement road (asphalt rough road) was set to 6 by one passenger.
The sound pressure level of the sound in the front seat when traveling at 0 km / H (226H through a 1/12 octave band filter)
z, 240 Hz, 253 Hz, three-channel partial overall) were measured, and an evaluation based on an increase / decrease value based on Comparative Example 1 and a sensory evaluation by a driver were performed. Regarding the increase / decrease value, the larger the minus value, the more preferable. The sensory evaluation was performed based on the magnitude of the resonance sound, and performed according to a 5-point method with Comparative Example 1 being 3 (the larger the value, the better).

(Rim assembling property) The mounting property when the tire was manually assembled into the rim to which the rising portion was fixed was examined. Table 1 shows the test results and the like.

[0019]

[Table 1]

As a result of the test, it was confirmed that each of the assemblies of the examples reduced the road noise as compared with the comparative example. Good results were also obtained for the rim assembly.

[0021]

As described above, in the assembly according to the present invention, the rising portion rises in the tire radial direction from the outer peripheral surface of the rim by using the centrifugal force, so that the rim assembly of the pneumatic tire is not impaired. In addition, the cavity resonance of the tire bore can be suppressed, and the road noise can be greatly reduced. In addition, by limiting the width Wa of the rising portion, the widthwise edge of the rising portion is suppressed from being located on the bead seat of the rim, and a rising portion is formed between the bead portion of the tire and the bead seat of the rim when assembling the rim. It is possible to effectively prevent the rim from being easily pinched, and to prevent deterioration of the rim assemblability.

According to the second aspect of the present invention, the rising portion is fixed at one end to the rim bottom, and protrudes in the width direction from the rim bottom and is not fixed to the outer peripheral surface of the rim. By securing the raised portion, the width of the rising portion is increased to secure the shielding area of the tire lumen, and when assembling the rim, the side of the rising portion on the non-fixed portion side is folded toward the rim bottom. Since the rising portion can be easily stored in the rim bottom, deterioration of the rim assemblage can be reliably prevented.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating an assembly of a pneumatic tire and a rim according to an embodiment.

FIG. 2 is a cross-sectional view along the tire equatorial plane.

FIG. 3 is a perspective view of a main part of the rim in a state where a centrifugal force acts on a rising portion.

FIG. 4 is a perspective view of a main part of the rim in a state where no centrifugal force acts on a rising portion.

FIG. 5 is a perspective view of a main part of the rim when the rim is assembled.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Assembly 2 Pneumatic tire 3 Rim 3a Rim bottom 4 Tire lumen 5 Rising part 5a One end side of rising part 6 Fixed part 7 Non-fixed part

Claims (2)

[Claims] 1. An assembly of a rim and a pneumatic tire that forms a tire cavity around the rim by mounting the pneumatic tire on the rim, the flexible member having one end fixed to an outer peripheral surface of the rim. And a rising portion that rises in the tire radial direction from the outer peripheral surface of the rim by a centrifugal force accompanying the rotation of the assembly and blocks the tire lumen, and the rising portion has a height Ha in the tire radial direction. Is 90 to 130% of the tire lumen height H, and the width Wa of the rising portion in the tire axial direction is 58 to 75% of the tire lumen maximum width. Assembly. 2. The rising portion has a substantially rectangular shape, and has, at one end thereof, a fixing portion having substantially the same width as a rim bottom and fixed to the rim bottom, and at least a widthwise direction from the rim bottom. The pneumatic tire and rim assembly according to claim 1, further comprising a non-fixed portion that protrudes to one side and is not fixed to the outer peripheral surface of the rim.