JP4153371B2 - Pneumatic tire and rim assembly - Google Patents

Description

【００４２】
テストの結果、実施例品及び比較例品は、何れもロードノイズ低減効果に優れていることが確認できた。又実施例品は、比較例品に比して高速耐久性を大巾に向上させうることが確認できた。
【００４３】
【発明の効果】
叙上の如く本発明は、制音体として無機繊維を絡み合わせた無機繊維多孔質材を用いているため、高速走行による熱劣化を防止しでき、変質による強度低下および変形を抑え、タイヤの高速耐久性を低下させることなくロードノイズ低減効果を長期に亘って発揮しうる。
【図面の簡単な説明】
【図１】 本発明の空気入りタイヤとリムとの組立体の一実施例を示す子午断面図である。
【図２】 そのタイヤ赤道に沿った周方向断面図である。
【図３】 制音体を拡大して示す断面図である。
【図４】 複数の分割片から制音体が形成される場合を単に示す組立体の周方向断面図である。
【図５】 制音体はタイヤに固定される場合を単に例示する組立体の子午断面図である。
【符号の説明】
２ 空気入りタイヤ
３ リム
３ａ１ ウェル部
４ タイヤ内腔
５ 制音体
５Ｓ 底面[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a pneumatic tire and rim assembly that can reduce road noise during traveling.
[0002]
[Prior art]
One of the tire noises is so-called road noise that produces a “go” sound in the frequency range of 50 to 400 Hz when traveling on the road surface, and the main cause is resonance vibration of air that occurs in the tire lumen ( Cavity resonance) is known.
[0003]
Therefore, in recent years, a sound control body using sponge material is arranged in the tire lumen, and resonance energy generated in the tire lumen is relaxed and absorbed, thereby suppressing cavity resonance and reducing road noise. Has been proposed (see, for example, Patent Documents 1 and 2). At this time, it is described that, as the sponge material, for example, a foamable porous material obtained by foaming rubber or synthetic resin, and a fiber porous material in which animal fibers, plant fibers, synthetic fibers or the like are entangled can be employed. .
[0004]
[Patent Document 1]
Japanese Patent Laid-Open No. 2002-67608 [Patent Document 2]
Japanese Patent Laid-Open No. 2002-144809
[Problems to be solved by the invention]
However, the assembly in which the sponge material is mounted in the tire lumen has a problem that it is difficult to exert a road noise reduction effect for a long period of time, and the high-speed durability of the tire is lowered.
[0006]
As a cause of this, it is considered that the noise control body collides with the tire cavity surface due to centrifugal force or lateral force during traveling, and the sound suppression body itself is destroyed. It is presumed that the internal high speed durability of the tire is reduced by damaging the inner liner rubber and the like forming the tire lumen surface. However, it has been found that the above problem cannot be solved sufficiently even when the sound control body is fixed to a tire or a rim to prevent a collision with the tire cavity surface.
[0007]
Therefore, as a result of further research by the present inventor, it has been found that deformation and destruction due to thermal deterioration of the sound damper are also greatly involved. That is, the temperature in the tire lumen rises to 160 to 180 ° C. during high speed running due to heat generated by running. However, since both the foamable porous material and the fiber porous material proposed as the sponge material are organic substances, they are thermally deteriorated, causing a shape change and a volume change (a change in porosity) to suppress cavity resonance. In addition to damage to the tire, the deterioration causes a drop in strength and breaks down, resulting in damage to the tire.
[0008]
Therefore, the present invention is based on the use of an inorganic fiber porous material in which inorganic fibers are entangled as a sound damping body, and prevents thermal deterioration due to high-speed running and suppresses strength reduction and deformation due to alteration, thereby reducing the An object of the present invention is to provide an assembly of a pneumatic tire and a rim that can exhibit a road noise reduction effect over a long period of time without reducing high-speed durability.
[0009]
[Means for Solving the Problems]
In order to achieve the above object, the invention according to claim 1 is characterized in that a sound damping body is disposed in a tire lumen formed by a rim and a pneumatic tire attached to the rim.
The noise damper forms a strip extending the result or hanging arm in side luminal surface of inorganic fibers intertwined allowed inorganic fibrous porous material in the circumferential direction continuously.
[0010]
The invention according to claim 1 is characterized in that the sound damping body is fixed to the rim side lumen surface using an adhesive.
[0011]
Further, in the invention according to claim 1, the sound damping body is a band-like body extending continuously in the circumferential direction on the rim side lumen surface, and the width W1 thereof is larger than the bottom width W2 of the well portion of the rim. The both sides of the sound control body exceeding the bottom width W2 are characterized by being non-adhered to the rim.
[0012]
The invention according to claim 2 is characterized in that the sound damping body has a length that wraps around the lumen surface once.
[0013]
The invention according to claim 3 is characterized in that the inorganic fiber porous material is rock wool and has a specific gravity of 0.01 to 0.2.
[0014]
In the invention according to claim 4, the inorganic fiber porous material is glass wool and has a specific gravity of 0.005 to 0.1.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a meridional cross-sectional view of an assembly of a pneumatic tire and a rim according to the present invention (hereinafter sometimes simply referred to as “assembly”), and FIG. 2 is a schematic cross-sectional view in the circumferential direction along the tire equatorial plane of the assembly. The figure is shown.
[0016]
In FIG. 1, an assembly 1 includes a pneumatic tire 2 (sometimes simply referred to as “tire 2”) and a rim 3, and the tire 2 and the rim 3 are mounted by attaching the tire 2 to the rim 3. And the tire lumen 4 is formed.
[0017]
The rim 3 has a well-known structure including an annular rim body 3a for mounting the tire 2 and a disk 3b that supports the rim body 3a and is fixed to an axle. In this example, a regular rim is used. The case is shown as an example. The “regular rim” is a rim defined for each tire in the standard system including the standard on which the tire is based, and is a standard rim for JATMA, “Design Rim” for TRA, ETRTO Then means "Measuring Rim".
[0018]
The tire 2 is, for example, a radial tire for a passenger car that is assembled with the bead portion 2a in close contact with the flange of the rim body 3a, and the tire side lumen of the lumen surface 4S surrounding the tire lumen 4 is provided. The surface 4S1 includes a tubeless structure formed of a so-called inner liner rubber made of low air permeability rubber. Thereby, the tire 2 forms an airtight tire lumen 4 with the rim body 3a.
[0019]
In the assembly 1, a sound damping body 5 extending in the tire circumferential direction is disposed in the tire lumen 4. The noise damper 5 is Ri Do inorganic fibers porous material intertwined inorganic fiber, illustrates a case which is formed as a long strip extending continuously in the tire circumferential direction.
[0020]
Examples of the inorganic fiber include glass fiber, rock fiber, slag fiber, silica fiber, quartz fiber, ceramic fiber, carbon fiber, metal fiber, and the like. For example, a cotton-like inorganic fiber porous material is formed by bonding.
[0021]
Since such an inorganic fiber porous material sufficiently holds an air chamber between fibers, it exhibits excellent vibration-proofing and sound-absorbing properties as well as a foamable porous material (sponge). Accordingly, resonance energy generated in the tire lumen 4 can be effectively relaxed and absorbed, and cavity resonance can be suppressed and road noise can be reduced. In addition, since it is formed of thermally stable inorganic fibers, the strength and shape of the sound damper 5 can be maintained without incurring alteration or deformation due to heat up to at least 350 ° C. Therefore, even when the temperature rises to a high temperature during high-speed traveling, shape change and volume change (change in porosity) can be prevented, and the effect of suppressing cavity resonance, that is, the effect of reducing road noise can be exhibited over a long period of time. In addition, it is possible to prevent damage to the tire due to the fragments, for example, it is possible to prevent the sound damping body itself from being destroyed due to strength reduction due to alteration, and the high-speed durability of the tire can be improved.
[0022]
Here, as the inorganic fiber porous material, glass wool in which the glass fiber is entangled in the form of cotton, and rock wool in which the rock fiber and the slag fiber are intertwined in the form of cotton are well known. In addition to being excellent, it can be suitably employed from the viewpoint of being inexpensive and easily available in the market.
[0023]
The glass wool is made of glass fiber, and is formed into a cotton shape by blowing molten glass, for example, with a high-pressure gas (a spraying method) or by blowing with a centrifugal force (a Hanger method). This glass wool is particularly easy to handle because of its high elastic force and excellent resilience, and it can be more suitably employed because it is resistant to bending and pulling. In the case of glass wool, it is preferable to use one having a specific gravity of 0.005 to 0.1. If it is less than 0.005, the effect of suppressing the cavity resonance is insufficient, and the strength of the sound damper 5 itself is reduced. It tends to impair durability. Conversely, if the specific gravity exceeds 0.1, the tire running performance tends to be adversely affected, such as an unnecessary increase in weight. Therefore, more preferably, the specific gravity is in the range of 0.01 to 0.08.
[0024]
In addition, the rock wool, strictly speaking, means a material made of rock fibers obtained by pulverizing a melt obtained by dissolving basalt at a high temperature into a cotton form by the spraying method or the Hager method. For example, it is defined to include a slag wool made of slag fibers obtained by forming a melt of residue (slag) produced by steel production into a fiber. Although this rock wool is somewhat inferior to the suppression effect of cavity resonance as compared with the glass wool, it is preferable in that it is cheaper and easily available. In the case of rock wool, it is preferable to use one having a specific gravity of 0.01 to 0.2. If it is less than 0.01, the effect of suppressing cavity resonance is insufficient, and the strength of the sound damper 5 itself is low. It tends to impair durability, such as decreasing. Conversely, if the specific gravity exceeds 0.2, the tire running performance tends to be adversely affected, for example, the weight increases unnecessarily. Therefore, more preferably, the specific gravity is in the range of 0.02 to 0.15.
[0025]
Further, the volume V2 of the sound damper 5 made of such an inorganic fiber porous material is set in the range of 0.4 to 20% of the total volume V1 of the tire lumen 4 as in the case of Patent Document 1. Preferably, when the ratio V2 / V1 is less than 0.4%, the effect of suppressing cavity resonance is not sufficiently exhibited. On the other hand, if the ratio V2 / V1 exceeds 20%, the cavity resonance suppression effect reaches its peak, and an unnecessary increase in weight and cost is caused.
[0026]
From such a viewpoint, if the volume V2 of the sound damper 5 satisfies the above range, the thickness T1, the width W1, and the length L1 are not particularly limited as shown in FIGS. In view of shape stability, a rectangular shape having a horizontally long cross section with W1> T1 can be preferably used. From the viewpoint of weight balance, as shown in FIG. 2, the sound damper 5 is wound once in the circumferential direction .
[0027]
The “volume V2 of the sound damper 5” is an apparent total volume of the sound damper 5 and is a volume determined from the outer shape of the sound damper 5 including the pores of the porous material. The “total volume V1 of the tire lumen 4” is approximately obtained by the following formula (1) in the normal state of the assembly 1.
V1 = A × {(Di−Dr) / 2 + Dr} × π (1)
In the formula, “A” is the cross-sectional area of the tire lumen 4 obtained by CT scanning of the tire lumen 4 in the normal state, and “Di” is the maximum outer diameter of the tire lumen 4 in the normal state shown in FIG. , “Dr” is the rim diameter, and “π” is the circumference. The “normal state” refers to a state in which the assembly is filled with a normal internal pressure and is not loaded. In addition, “regular internal pressure” is the air pressure that each standard defines for each tire in the standard system including the standard on which the tire is based. The maximum air pressure for JATMA and the table “TIRE LOAD LIMITS AT for TRA” The maximum value described in “VARIOUS COLD INFLATION PRESSURES”, “INFLATION PRESSURE” if it is ETRTO, but if the tire is for a passenger car, it will be 200 kPa considering the actual frequency of use.
[0028]
Next, the noise damper 5 is fixed to the Trim side cavity surface 4S2. The reason for fixing is that a large centrifugal force or lateral force acts on the sound control body 5 during high-speed traveling. If the sound control body 5 is not fixed, the sound control body 5 moves and contacts the lumen surface 4S. The body 5 itself is destroyed. As a result, even when the noise control body 5 is formed of a porous inorganic fiber material, the effect of suppressing cavity resonance cannot be exhibited over a long period of time, and the effect of improving high-speed durability cannot be obtained.
[0029]
Therefore, by fixing the sound damping body 5, coupled with the use of the inorganic fiber porous material described above, the effect of suppressing cavity resonance can be exhibited over a long period of time, and high-speed durability can be improved. . In this example, the sound-damping body 5 has a long band shape with a horizontally long cross section, and its bottom surface 5S is fixed to the well portion 3a1 of the rim 3 with an adhesive .
[0030]
As schematically shown in FIG. 3, the sound damping body 5 has a width W1 larger than the bottom width W2 of the well portion 3a1, and both side portions 5e of the sound damping body 5 exceeding the bottom width W2 are rims. 3 and non-adhesive. Thereby, rim assemblability can be ensured. As the bonding method, it is preferable to apply and bond the adhesive in a solid shape or a spot shape over the entire length of the sound damper 5.
[0031]
As the adhesive, a synthetic rubber-based liquid adhesive such as a solution type obtained by dissolving synthetic rubber in an organic solvent and a latex type dispersed in water can be suitably used. In particular, a chloroprene-based solution-type adhesive using chloroprene rubber as a synthetic rubber can be used more preferably because it has excellent adhesive strength and is flexible and resistant to bending and impact. At this time, the content of the chloroprene rubber is preferably 25 to 35 parts by weight when the total amount of the synthetic rubber adhesive is 100 parts by weight, and if it is less than 25 parts by weight, the adhesive strength tends to be impaired, and 35 parts by weight is reduced. When it exceeds, it becomes difficult to apply because of high viscosity.
[0032]
Next, FIG. 4 merely illustrates a case where the sound damping body 5 is formed by a plurality of divided pieces 5A divided in the circumferential direction, in addition to being formed by a single band-shaped body. At this time, the divided pieces 5A are fixed at equal intervals in the circumferential direction. Although the number of the divided pieces 5A is not particularly limited, it is preferably 10 or less, more preferably 6 or less from the viewpoint of workability of adhesion, but 3 or more is preferable from the viewpoint of uniformity. good.
[0033]
FIG. 5 simply shows a case where the sound damping body 5 is bonded to the tire side lumen surface 4S1. At this time, it is preferable to adhere to the tread region J having a large rigidity in order to suppress the influence of the noise control body 5 on the tire running performance. The “tread region J” means a region between radial lines passing through both outer ends of the belt layer 7.
[0034]
In addition, the said adhesive agent is used for fixation to the tire 2 or the rim | limb 3 of the noise suppression body 5 .
[0035]
The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the illustrated embodiments, and can be implemented in various forms.
[0036]
【Example】
Based on the specifications of Table 1, an assembly in which a long band-shaped sound absorber is bonded to the tread back surface of the tire (195 / 60R15) or the bottom surface of the well portion of the rim (15 × 6JJ) over one round, Road noise performance and tire high speed durability were tested.
[0037]
The noise control body was formed using glass wool, rock wool, which are inorganic fiber porous materials, and soft urethane sponge, which is a foamable porous material. Glass wool uses Magroll RR2425 made by Mag Co., Ltd. with a specific gravity of 0.024, rock wool uses MG Belt No. 1 made by Nichias Co., Ltd. with a specific gravity of 0.025, and soft urethane sponge (open cells) is Calm flex F-50 manufactured by Inoac Co., Ltd. having a specific gravity of 0.02 was used.
[0038]
For adhesion, use a chloroprene-based solution type adhesive (Model No. 9383 manufactured by No-Tape Kogyo Co., Ltd.). Each test was conducted after 1 day.
[0039]
(1) Road noise performance:
The rim was assembled at an internal pressure of 200 kPa and mounted on all wheels of a vehicle (domestic 2000cc FR vehicle), and one person took a road noise measurement road (asphalt rough road) at a speed of 60 km / h. Measure the sound in the front seat car at that time, calculate the partial overall of 226Hz, 240Hz, 253Hz, and evaluate with the increase / decrease value (dB (A)) based on the conventional example (no sound control tool) did. -(Minus) display means a reduction in road noise.
[0040]
(2) High speed durability:
The speed and time when the tire is damaged by running on the drum by the step speed method of 200km / h to 10km / h-20 minutes under the internal pressure (280kPa) with the load specified by ECE30. Was measured.
[0041]
[Table 1]

[0042]
As a result of the test, it was confirmed that the example product and the comparative product were all excellent in road noise reduction effect. In addition, it was confirmed that the example product can greatly improve the high-speed durability as compared with the comparative product.
[0043]
【The invention's effect】
As described above, the present invention uses an inorganic fiber porous material in which inorganic fibers are entangled as a sound damper, so that thermal degradation due to high-speed running can be prevented, strength reduction and deformation due to alteration are suppressed, and the tire A road noise reduction effect can be exhibited over a long period of time without reducing high-speed durability.
[Brief description of the drawings]
FIG. 1 is a meridional sectional view showing an embodiment of an assembly of a pneumatic tire and a rim according to the present invention.
FIG. 2 is a circumferential sectional view along the tire equator.
FIG. 3 is an enlarged cross-sectional view of a sound control body.
FIG. 4 is a cross-sectional view in the circumferential direction of an assembly simply showing a case in which a sound damping body is formed from a plurality of divided pieces.
[5] the noise damper is a meridional section view of an assembly for merely illustrative of the case to be fixed to the tire.
[Explanation of symbols]
2 Pneumatic tire 3 Rim 3a1 Well part 4 Tire lumen 5 Sound absorber 5S Bottom

Claims (4)

In the tire lumen formed by the rim and the pneumatic tire attached to the rim, a sound damping body is arranged,
The noise damper is a strip extending the result or hanging arm in side luminal surface of inorganic fibers intertwined allowed inorganic fibrous porous material continuously in the circumferential direction,
The sound absorber is fixed to the rim side lumen surface using an adhesive ,
Moreover, the tire has a width W1 larger than the bottom width W2 of the well portion of the rim, and both side portions of the noise suppression body exceeding the bottom width W2 are not bonded to the rim. And rim assembly. The tire and rim assembly according to claim 1, wherein the noise control body has a length that wraps around the lumen surface once. The pneumatic tire and rim assembly according to claim 1 or 2, wherein the inorganic fiber porous material is rock wool and has a specific gravity of 0.01 to 0.2. The pneumatic tire / rim assembly according to claim 1 or 2 , wherein the inorganic fiber porous material is glass wool and has a specific gravity of 0.005 to 0.1.

Images