JP4363515B2 - Pneumatic tire - Google Patents

Description

【００２２】
【発明の効果】
上述したように本発明の空気入りタイヤによれば、タイヤ空洞部にタイヤ周方向に屈曲を繰り返す仕切板を配置したことにより、タイヤ空洞部を長さの短い複数の空間に区分するため、空洞共鳴周波数を高くする方へずらせ、タイヤ内空洞共鳴振動を低減することができる。また、上記仕切板がタイヤ周方向に波状に屈曲を繰り返し、その繰り返し周期をタイヤ１周当たり１以上にしたため、タイヤ内周面の支持を全周に渡るようにし、タイヤ周方向剛性を均一にすることができる。
【図面の簡単な説明】
【図１】本発明の実施形態からなる空気入りタイヤを示し、（Ａ）は（Ｂ）におけるＡ−Ａ矢視図で、仕切板だけを示し、（Ｂ）は（Ａ）におけるＢ−Ｂ矢視の子午線断面図を示す。
【図２】図１（Ａ）においてＣ−Ｃ矢視方向（タイヤ周方向）に仕切板をタイヤ横断面に投影したときの投影図である。
【図３】図１（Ａ）において仕切板をタイヤ半径方向にタイヤ内周面に投影したときのタイヤ１周分の展開図である。
【符号の説明】
１ 空気入りタイヤ
２ 空洞部
３ 仕切板[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a pneumatic tire, and more particularly to a pneumatic tire that reduces cavity resonance vibration in the tire while maintaining rigidity in the tire circumferential direction uniformly.
[0002]
[Prior art]
The vibration generated by the tire picking up the unevenness of the road surface is propagated to the vehicle interior via the axle, and the noise generated when it resonates in the vehicle interior is called road noise. The frequency of the road noise is in the range of 50 to 400 Hz, and it is known that the noise around the frequency of 250 Hz is generated by the cavity resonance vibration of the air in the tire cavity.
[0003]
Conventionally, as a measure for reducing the cavity resonance vibration in the tire as described above, many proposals have been made in which partition walls are intermittently projected on the tire inner wall of the tire cavity at regular intervals in the circumferential direction. (Patent Document 1 etc.). However, any of these conventional measures has no problem in arranging the partition walls at equal intervals with respect to the weight balance in the tire circumferential direction, but unevenness in the rigidity in the tire circumferential direction cannot be avoided. This non-uniform rigidity in the tire circumferential direction has reduced tire uniformity and reduced riding comfort.
[0004]
[Patent Document 1]
JP-A-5-294102
[Problems to be solved by the invention]
An object of the present invention is to provide a pneumatic tire that reduces the cavity resonance vibration in the tire while making the rigidity in the tire circumferential direction uniform.
[0006]
[Means for Solving the Problems]
The pneumatic tire of the present invention to achieve the above object, the tire cavity, and a height in the tire radial direction at a constant, while repeatedly bent in a wavy in the tire circumferential direction at a constant amplitude W in the tire width direction place the partition plate continuously extending, it is characterized in that it has the bending repetition period number 1 or more per one round tire.
[0007]
Since the partition plate that repeatedly bends in the tire circumferential direction is arranged in the tire cavity in this manner, the tire cavity is partitioned into a plurality of short spaces, so that the cavity resonance frequency is increased by the short cavity space. It shifts so that the cavity resonance vibration in the tire near 250 Hz is reduced. Further, the partition plate is repeatedly bent in a wavy shape with respect to the tire circumferential direction, and the repetition period is set to 1 or more per tire circumference, so that the tire inner surface extends over the entire circumference in the tire circumferential direction and the entire width in the tire width direction. Since it supports continuously, the rigidity of a tire peripheral direction can be made uniform.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be specifically described with reference to embodiments shown in the drawings.
1 (A) and (B) show a pneumatic tire according to an embodiment of the present invention, and FIG. 1 (A) is an AA arrow view of FIG. 1 (B) and shows only a partition plate. In addition, FIG. 1B is a meridian cross-sectional view taken along the line BB in FIG.
[0009]
In these drawings, 1 is a pneumatic tire, 2 is a hollow portion of the pneumatic tire 1, and 3 is a partition plate inserted into the hollow portion 2. The partition plate 3 has an annular (see FIG. 1 (A)) is a side view, and is continuously extended while repeatedly bent in a wavy in the tire circumferential direction at regular amplitude W in the tire width direction . Further, the partition plate 3 continuously contacts the inner peripheral surface of the pneumatic tire 1 with the outer peripheral edge bent in a wave shape in this way.
[0010]
When the partition plate 3 that repeatedly bends in a wavy manner as described above is projected onto the tire inner circumferential surface in the tire radial direction, the projected development view per tire circumferential length L is as shown in FIG. In this way, when the partition plate 3 repeats bending with an amplitude W, the number of cycles is at least 1 per tire circumferential length L. The number of bending repetition cycles per tire circumferential length L is not particularly limited as long as it is at least one. As described above, when the bending repetition period is at least 1 per circumferential length L of the tire, the support of the inner peripheral surface of the tire by the partition plate 3 can be provided over almost the entire tire width (projection of the partition plate 3 in FIG. 2). (See figure).
[0011]
As described above, in the pneumatic tire 1 of the present invention, since the partition plate 3 that repeatedly bends in a wavy manner is inserted into the tire cavity 2, the tire cavity 2 is divided into a plurality of shortened spaces. This shortened cavity space can shift the cavity resonance frequency higher. Due to the deviation of the cavity resonance frequency, the cavity resonance vibration in the tire near 250 Hz is reduced, and road noise can be improved. Moreover, the partition plate 3 inserted into the tire cavity 2 continuously supports the inner surface of the pneumatic tire 1 over the entire circumferential length L in the tire circumferential direction (see FIG. 3), and also has an amplitude W in the tire width direction. The entire width is supported by bending (see FIG. 2). Therefore, not only the weight balance in the tire circumferential direction of the pneumatic tire 1 can be made uniform, but also the rigidity in the tire circumferential direction can be made uniform.
[0012]
In the present invention configured as described above, the area when the partition plate 3 is projected on the tire radial cross section (meridian cross section) in the tire circumferential direction is the tire radial cross section area (the meridian cross sectional area) of the tire cavity 2. ) Of 15 to 85%. If the projected area of the partition plate with respect to the tire meridian cross section is smaller than 15%, the effect of improving road noise cannot be sufficiently obtained. On the other hand, if it is larger than 85%, the partition plate tends to be damaged.
[0013]
In the present invention, the number of repetitions (number of cycles) of bending per circumferential length L of the partition plate may be at least one. Thus, by setting the number of bending repetition periods to 1 or more, it is possible to achieve uniform tire circumferential rigidity as well as an effect of reducing road noise. When the number of bending repetition cycles is less than 1, the tire circumferential rigidity becomes non-uniform, and the riding comfort deteriorates. Moreover, since the division of the tire cavity by the partition plate is incomplete, the effect of reducing road noise is insufficient.
[0014]
Further, the number of partition plates having the above-described structure is not necessarily one, and a pair of left and right sides may be provided symmetrically with respect to the tire equatorial plane E, as shown by a chain line 3 'in FIG. Good.
[0015]
In the present invention, the material of the partition plate is not particularly limited, but it is preferable to use rubber, resin or the like in order to reduce damage to the tire. Particularly preferably, rubber or elastic resin is used.
[0016]
【Example】
Sixteen pneumatic tires having the same structure with a tire size of 205 / 55R16 are prepared, and in each of the eight tire cavities, the structure shown in FIG. Thus, four tires (Example 1) into which one rubber partition plate having a bending repetition frequency of 1 is inserted and two rubber partition plates having the same configuration are arranged symmetrically with respect to the tire equatorial plane. Four tires (Example 2) were manufactured, and the other four tire cavities had the structure shown in FIG. 1 and had a projected area of 40% on the meridian cross section of the partition plate, and the number of bending repetition cycles. A tire (comparative example) in which a rubber partition plate having a thickness of 0.5 was inserted was manufactured. Further, a tire (conventional example) was manufactured in which the remaining four tire cavities were provided with partition plates projecting at a projection area of 15% at four locations spaced at equal intervals on the inner peripheral surface of the tire.
[0017]
With respect to the four types of tires manufactured as described above, the air column resonance level and RFV (variation of reaction force in the tire radial direction) were measured by the following test methods, and the results are shown in Table 1.
[0018]
[Air column resonance level]
The test tire was filled with an air pressure of 200 kPa, mounted on a 2000 cc FR vehicle, and the sound pressure level in the vehicle near a noise frequency of 250 Hz was measured by the test method of JASO C606.
[0019]
[RFV (variation of reaction force in the tire radial direction)]
As an evaluation of the tire circumferential direction rigidity balance, RFV was measured based on JASO C607 (a method for testing the tire uniformity of automobile tires).
[0020]
The evaluation was performed using the reciprocal of the measured value, and indicated by an index with the reciprocal value of the conventional example being 100. A larger index means that the tire circumferential rigidity balance is more uniform.
[0021]
[Table 1]

[0022]
【The invention's effect】
As described above, according to the pneumatic tire of the present invention, since the partition plate that repeatedly bends in the tire circumferential direction is arranged in the tire cavity portion, the tire cavity portion is divided into a plurality of short spaces. The resonance frequency in the tire can be reduced by shifting the resonance frequency higher. Further, since the partition plate repeatedly bends in a wavy shape in the tire circumferential direction and the repetition period is set to 1 or more per tire circumference, the tire inner circumferential surface is supported over the entire circumference so that the tire circumferential rigidity is uniform. can do.
[Brief description of the drawings]
FIG. 1 shows a pneumatic tire according to an embodiment of the present invention, (A) is an AA arrow view in (B), showing only a partition plate, (B) is BB in (A). The meridian cross-sectional view of the arrow view is shown.
FIG. 2 is a projection view when a partition plate is projected on a tire cross section in the direction of arrow CC (tire circumferential direction) in FIG. 1 (A).
FIG. 3 is a development view of one round of the tire when the partition plate is projected on the tire inner circumferential surface in the tire radial direction in FIG. 1 (A).
[Explanation of symbols]
1 Pneumatic tire 2 Cavity 3 Partition plate

Claims (4)

The tire cavity, and a height in the tire radial direction at a constant, place the partition plate continuously extending while repeatedly bent in a wavy in the circumferential direction of the tire in the tire width direction at a constant amplitude W, the A pneumatic tire in which the number of bending cycles is 1 or more per tire circumference.   2. The pneumatic tire according to claim 1, wherein an area of the partition plate projected onto a tire meridian cross section in a tire circumferential direction is 15 to 85% of a meridian cross sectional area of the tire cavity.   The pneumatic tire according to claim 1 or 2, wherein a pair of left and right parts are arranged symmetrically with respect to the tire equator plane.   The pneumatic tire according to claim 1, wherein the partition plate is formed of rubber or resin.

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