JP4109521B2 - Tire set - Google Patents

Description

【００４９】
【表２】

【００５０】
【発明の効果】
本発明は、叙上の如く構成しているため、荷重時の撓みを適度に確保でき、優れた乗り心地性を発揮しうるとともに、温度上昇による永久変形を防止して優れた乗り心地性を長期に亘って維持できる。しかも走行の時間経過に伴う乗り心地性の変動を抑えて違和感をなくすことができる。又耐偏摩耗性能を高め、摩耗寿命の向上を図ることができる。
【図面の簡単な説明】
【図１】本発明のタイヤセットの一実施例を示す断面図である。
【図２】２液混合硬化型の樹脂材の充填を説明する線図である。
【図３】正規荷重を負荷した場合の接地面の形状を示す線図である。
【符号の説明】
２ トレッド部
３ サイドウォール部
４ ビード部
５ ビードコア
６ カーカス
７ ブレーカ層
１０ タイヤ
１１ リム
１２ 充填材
Ｃ タイヤ赤道
Ｆ 接地面の形状
Ｈ タイヤ内腔
ＴＥ トレッド接地縁[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a tire set that does not generate punctures and that can be suitably used for new transportation vehicles such as monorails and route buses.
[0002]
[Prior art]
In tires, pneumatic tires in which air is filled in the tire lumen are mainly used from the viewpoints of ride comfort, high-speed running performance, and weight reduction. However, new transportation vehicles such as subways and monorails, and route buses that run in the city are operated at medium and low speeds and are frequently started and stopped. In recent years, non-puncture tires have been strongly desired to be applied to this type of vehicle.
[0003]
On the other hand, as a non-punctured tire, the tire lumen formed by the rim-assembled tire and the rim is filled with a liquid urethane resin and cured, and as proposed in Patent Document 1, etc. It is known that a foamable composition is filled into a tire lumen and then the foamable composition is changed into a closed cell foam by heating or the like.
[0004]
[Patent Document 1]
Japanese Patent Laid-Open No. 2001-294012
[Problems to be solved by the invention]
However, the former is inferior in the effect of mitigating the impact received from the road surface because the filler is a non-foamed material, and the ride comfort is impaired. In the latter case, since the filler is a foam, it has an excellent impact mitigating effect in the initial stage of use. However, when used as a heavy load tire, the closed cells tend to be crushed and permanently deformed. .
[0006]
In particular, in the above-mentioned new transportation vehicles and the like, although they are operated mainly at medium and low speeds, they are frequently started and stopped, so that the temperature inside the tire rises significantly due to the heat storage phenomenon in the tire. As a result, both the non-foamed material and the foamed material are likely to be permanently deformed in the filler, and the riding comfort tends to be further deteriorated. In addition, the temperature difference inside the tire becomes large between the start of running due to the heat storage phenomenon and the time of running for several hours, but the elastic characteristics of the filler change with this temperature difference, so that the ride comfort becomes the running time. There also arises a problem that it varies with time.
[0007]
Furthermore, in this type of non-punctured tire, the internal pressure at the shoulder portion becomes lower than that at the center of the tread, and the internal pressure becomes non-uniform. Therefore, there is a problem that uneven wear becomes noticeable at this shoulder portion and wear life is impaired. .
[0008]
Therefore, the present invention regulates the complex elastic modulus E * of the filler at 70 ° C. in the range of 0.4 to 2.0 Mpa, the tangent loss (tan δ) in the range of 0.01 to 0.08, and Based on the ratio Lc / Ls between the contact length Ls in the circumferential direction at the tread contact edge in the ground shape and the contact length Lc at the tire equator being 0.88 to 0.98, deflection under load Can be secured moderately, can exhibit excellent ride comfort, can prevent permanent deformation due to temperature rise, and can maintain excellent ride comfort over a long period of time, and the ride comfort of the ride over time An object of the present invention is to provide a tire set that can suppress unevenness and eliminate uncomfortable feeling while suppressing uneven wear and improving wear life.
[0009]
[Means for Solving the Problems]
In order to achieve the object, the invention of claim 1 of the present application includes a carcass extending from a tread portion through a sidewall portion to a bead core of the bead portion, a breaker layer disposed inside the tread portion and outside the carcass. A toroid-like tire comprising a tire, a rim for assembling the tire, and a filling material filled in a tire lumen surrounding the tire and the rim. With
The filler has a complex elastic modulus E * at 70 ° C. of 0.4 to 2.0 Mpa and a tangent loss (tan δ) of 0.01 to 0.08,
The shape of the contact surface when a normal load is applied is such that the ratio Lc / Ls between the contact length Ls in the circumferential direction at the tread contact edge and the contact length Lc at the tire equator is 0.88 to 0.98. It is characterized by that.
[0010]
According to a second aspect of the present invention, the tire is a heavy-duty radial tire, and the filler is made of a urethane resin.
[0011]
In the invention of claim 3, the carcass is composed of one carcass ply using a steel carcass cord, and the breaker layer is composed of two or more breaker plies using a steel breaker cord. It is a feature.
[0012]
According to a fourth aspect of the invention, the shape of the contact surface is characterized in that the contact length L in the circumferential direction gradually decreases from the tire equator toward the tread contact edge.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view showing a case where the tire set of the present invention is formed for a heavy-duty vehicle.
In FIG. 1, a tire set 1 includes a toroidal tire 10, a rim 11 for assembling the tire 10, and a non-foaming filling injected into a tire lumen H surrounded by the tire 10 and the rim 11. It is comprised from the material 12, and non-puncture performance is provided by this.
[0014]
In the present example, the tire 10 includes a carcass 6 extending from the tread portion 2 through the sidewall portion 3 to the bead core 5 of the bead portion 4, and a breaker layer disposed inside the tread portion 2 and outside the carcass 6. A heavy-duty radial tire comprising 7 and a conventional heavy-duty pneumatic tire can be suitably employed.
[0015]
The carcass 6 is formed of one or more carcass plies in which carcass cords are arranged at an angle of, for example, 70 to 90 degrees with respect to the tire circumferential direction. In this example, the case where it consists of one carcass ply 6A using a steel cord as a carcass cord is illustrated.
[0016]
The carcass ply 6A has folded portions 6b that are folded and locked around the bead core 5 from the inside to the outside on both sides of the ply body portion 6a straddling the bead cores 5 and 5. The ply body portion 6a A bead apex rubber 8 extending radially outward from the bead core 5 is disposed between the bead portion 4 and the folded portion 6 b and is reinforced from the bead portion 4 to the sidewall portion 3.
[0017]
The breaker layer 7 is formed of two or more, usually 3 to 4 breaker plies using steel cords as breaker cords. In this example, steel cords are arranged at an angle of, for example, 60 ± 15 ° with respect to the tire circumferential direction, and the first breaker ply 7A is disposed at the radially innermost position, and for example, 10 with respect to the tire circumferential direction. The case of the four-sheet structure with the second to fourth breaker plies 7B, 7C, 7D arranged at a small angle of ˜35 ° is illustrated. The breaker plies 7 </ b> A to 7 </ b> D are provided with one or more places where the cords cross each other between the plies, and are superposed to enhance the breaker rigidity and reinforce the tread portion 2 with a tagging effect.
[0018]
The rim 11 has a well-known structure, and is provided with an L-shaped seating portion 11B including a rim seat 11B1 that receives the bottom surface of the bead and a flange 11B2 that receives the side surface of the bead at the outer end in the tire axial direction of the rim base 11A. In this example, the case where the rim base 11A is a flat flat bottom rim is illustrated. However, a shallow bottom rim and a deep bottom rim can be appropriately employed depending on the tire 10.
[0019]
In the tire set 1 of the present embodiment, the tire body H surrounded by the tire 10 and the rim 11 is filled with the filler 12 made of a two-component mixed curable resin without any gap, and the tire 10 and the rim 11 Are integrated.
[0020]
The filling body 12 is a non-foamed body having no closed cells or open cells, and after the tire 10 and the rim 11 are assembled to each other, as shown schematically in FIG. It is formed by injecting and curing a two-component mixed curing liquid resin material Pa.
[0021]
Specifically, in this example, the liquid resin material Pa is injected from the injection hole 13 provided in the rim base 11A of the rim 11 with a pressure of, for example, 100 to 200 kPa. In this example, for example, an injection needle-like air vent needle 14 is inserted in advance into the sidewall portion 3 that faces upward when the tire is placed horizontally, and the air in the tire lumen H is sequentially discharged. Note that an air vent hole may be directly formed in the sidewall portion 3 without using the air vent needle 14.
[0022]
At this time, the liquid resin material Pa is preferably set to have a viscosity at 25 ° C. during mixing (Ford Cup No. 4) of 5 to 30 seconds, which is lower than the conventional viscosity. It is also preferable to suppress the increase in viscosity later at 25 ° C. to 20 seconds or less and lower the increase in viscosity than in the past. The viscosity is a Ford Cup No. 4 described in JIS K5400, 4.5.4. It is the value measured based on 4 methods.
[0023]
By specifying the viscosity in this way, it is possible to optimize the injection of the resin material Pa, to prevent the occurrence of air accumulation in the tire lumen H, and to apply a sufficient internal pressure to the tire 10. Become. Also, the resin material Pa filled without gaps flows moderately, and the internal pressure is evenly transmitted to each part of the tire 10 before it begins to harden, so that the internal pressure can be made uniform, and the internal pressure at the shoulder portion can be kept at the center of the tread. It can also contribute to the suppression of uneven wear at the shoulder, such as close to the internal pressure on the side.
[0024]
If the viscosity is higher than 30 seconds, the injection takes too much time, the resin material Pa begins to harden gradually, and a defective product such as air remains in the tire lumen H occurs. There is a tendency that the internal pressure required for the heavy-duty tire is not sufficiently applied, or that the internal pressure varies at each part of the tire. Even when the viscosity is less than 5 seconds, the injection pressure cannot be increased. As a result, the air escape is similarly deteriorated, and it is difficult to sufficiently increase the tire internal pressure. From such a viewpoint, the viscosity is more preferably in the range of 10 to 20 seconds.
[0025]
If the increase in viscosity exceeds 20 seconds, the product tends to harden during injection, resulting in defective products, or insufficient flow of the resin material Pa after filling, making it difficult to uniformly increase the tire internal pressure. .
[0026]
The reason why the two-component mixed curable resin is used as the filler 12 is that if a normal rubber material is used, the volume of the filler is large, and thus vulcanization heating after filling takes a long time. Moreover, this vulcanization heating may adversely affect the rubber of the tire base.
[0027]
And in the present invention, in order to ensure excellent ride comfort, while maintaining this excellent ride comfort over a long period of time, and also to suppress the change in ride comfort with the passage of time of travel, The complex elastic modulus E * at 70 ° C. of the cured filler 12 is regulated in the range of 0.4 to 2.0 Mpa, and the tangent loss (tan δ) is regulated in the range of 0.01 to 0.08.
[0028]
This is because, in order to ensure excellent ride comfort, it is important to obtain a moderate deflection at the time of loading. For this reason, the complex elastic modulus E * at 70 ° C. is 0.4 to 2.0 Mpa. The range. When the complex elastic modulus E * is less than 0.4 Mpa, the filler 12 is too soft and the tire tends to roll to the left and right. On the other hand, if it exceeds 2.0 Mpa, it will be too hard and the deflection will be too small and the impact mitigating effect will be insufficient. Therefore, from such a viewpoint, it is preferable that the complex elastic modulus E * is in the range of 0.7 to 1.5 Mpa.
[0029]
The reason why the complex elastic modulus E * at 70 ° C. is regulated is that the internal temperature during running of the tire of the present invention is approximately 70 ° C., and the elastic characteristics are regulated under actual temperature conditions. This makes it possible to control the ride comfort more accurately.
[0030]
Further, in order to maintain this riding comfort over a long period of time, it is necessary to prevent permanent deformation due to the temperature rise of the filler 12, and for this reason, the tangent loss (tan δ) at 70 ° C. is 0.01. It is regulated in the range of ~ 0.08. When the tangent loss (tan δ) exceeds 0.08, the tire internal temperature rises significantly beyond 70 ° C., and the ride comfort cannot be maintained, for example, causing permanent deformation of the filler 12. On the other hand, if it is less than 0.01, the vibration absorption of the tire becomes too small, and there is a problem that the riding comfort is deteriorated.
[0031]
Further, by regulating the tangent loss (tan δ) within the above range, the temperature difference between the initial traveling and after traveling for several hours can be kept low. Therefore, it is possible to reduce the change in the elastic characteristics of the filler 12 due to this temperature difference, to eliminate the fluctuation of the riding comfort during traveling, and to eliminate the uncomfortable feeling of riding comfort. The complex elastic modulus E * and the tangent loss (tan δ) are values measured using a viscoelastic spectrometer manufactured by Iwamoto Seisakusho under conditions of a frequency of 10 Hz and a dynamic strain rate of 2%.
[0032]
Next, examples of the two-component mixed curable resin include urethane resin, epoxy resin, and acrylic resin. From the viewpoint of regulating the complex elastic modulus E * and the tangent loss (tan δ) within the above ranges, urethane is used. Resins can be preferably used.
[0033]
As is well known, this urethane resin is cured at room temperature by mixing a first liquid containing an isocyanate compound and a second liquid containing a polyamine, a polyol or the like that crosslinks an isocyanate group in the first liquid. Since it is a composition and has rubber-like elasticity, it can be preferably employed as the filler 12.
[0034]
Here, in the urethane resin, in order to make the complex elastic modulus E * at the time of curing in the range of 0.4 to 2.0 Mpa, urethane having a low glass transition temperature (Tg) is used in this example.
Further, in order to make the tangent loss (tan δ) in the range of 0.01 to 0.08, similarly, in this example, urethane having a low glass transition temperature (Tg) is used.
[0035]
Examples of the isocyanate compound include diphenylmethane diisocyanate (MDI), toluylene diisocyanate (TDI), naphthylene-1,5-diisocyanate, o-toluylene diisocyanate, triphenylmethane triisocyanate, and tris (p-isocyanatephenyl) thiophos. There are monomers such as phyto, polymethylene polyphenyl isocyanate, hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, isophorone diisocyanate and xylylene diisocyanate (XDI), or modified products thereof, which can be used alone or in combination.
[0036]
Examples of the polyamine include terminal amino-modified polyalkylene glycols such as terminal amino-modified polyethylene glycol and terminal amino-modified polypropylene glycol; amino-modified poly (meth) acrylate polymers, amino-modified vinyl polymers, amino-modified polyesters, amino-modified polycarbonates. , Polymers having two or more amino groups in one molecule such as polyallylamine and polyethyleneimine; ethyleneamines, diethylaminopropylamine, dimethylaminopropylamine, N-aminoethylpiperazine, trimethylhexamethylenediamine, modified aliphatic amines Aliphatic amines such as m-phenylenediamine, diaminodiphenylmethane, diaminodiphenylsulfone, metaxylylenediamine, and aromatic amine modified products There is Min, etc., may use this alone or in combination.
[0037]
Examples of the polyol include polypropylene glycol, polyethylene glycol, glycerin, trimethylolpropane, pentaerythritol, sorbitol, hydroxyl group-modified (meth) acrylic polymer, hydroxyl group-modified vinyl polymer, hydroxyl group-modified polyester, and hydroxyl group-modified polycarbonate. These can be used alone or in combination.
[0038]
Next, in the tire set 1 of the present embodiment, as described above, by specifying the viscosity at the time of mixing the resin material Pa, the internal pressure can be made uniform as compared with the conventional tire set. The contact pressure at the shoulder portion is relatively low, and uneven wear such as shoulder drop wear and heel & toe wear tends to occur at the shoulder portion.
[0039]
Therefore, as shown in FIG. 1, the radius of curvature R (tread radius R) of the tread profile TP of the tire 1 in the state where the filler 12 is filled is 3.0 to 5.0 times the tread ground contact width TW. It is set larger than the tread profile in a state in which a normal pneumatic tire is filled with normal internal pressure, such as a range. Thereby, as shown in FIG. 3, in the contact surface shape F when a normal load is applied, the ratio between the contact length Ls in the circumferential direction at the tread contact edge TE and the contact length Lc at the tire equator. Lc / Ls is increased to a range of 0.88 to 0.98, and uneven wear at the shoulder portion is further suppressed.
[0040]
At this time, it is preferable that the contact length L in the circumferential direction gradually decreases from the tire equator C toward the tread contact edge TE, thereby achieving uniform wear over the entire tread and improving the wear life. Yes.
[0041]
When the tread profile TP is not a single arc, the radius of curvature of the three-point arc passing through the tread equator point CO and the tread grounding edge TE, TE is defined as the curvature radius R. The normal load is a standard load set for a pneumatic tire having a tire size equal to that of the tire 1. If the pneumatic tire is JATMA, the maximum load capacity is indicated. The maximum value described in “LOAD LIMITS AT VARIOUS COLD INFLATION PRESSURES”. If ETRTO, it means “LOAD CAPACITY”.
[0042]
When the contact length ratio Lc / Ls is less than 0.88, uneven wear suppression at the shoulder portion is insufficient. Conversely, when it exceeds 0.98, center wear or punching wear on the tire equator side occurs. It becomes a trend.
[0043]
As described above, the particularly preferred embodiment of the present invention has been described in detail. The present invention is particularly effective for heavy-duty vehicles. However, for example, it can be formed for light trucks and passenger cars. Without being limited, the present invention can be carried out with various modifications.
[0044]
【Example】
A tire set having a tire size of 13 / 80R20 having the tire structure shown in FIG. 1 was prototyped based on the specifications shown in Table 1, and the riding comfort and uneven wear performance at that time were tested. The results are shown in Table 1. The specifications other than those in Table 1 are substantially the same for each tire set, and the tire specifications are shown in Table 2.
[0045]
(1) Ratio of contact length Lc / Ls;
The standard load (JATMA maximum load capacity; 35.8 kN) for a pneumatic tire having a tire size of 13 / 80R20 was measured by calculating the contact lengths Lc and Ls in the shape of the contact surface when the sample tire was loaded.
[0046]
(2) Uneven wear performance After mounting a test tire on a large bus and running on a general road for 20,000 km with a load equivalent to the standard load, the wear amount αc at the tire equator and the wear amount at the tread contact edge αs was measured, and the difference αc−αs was compared. The difference αc−αs is + for shoulder wear and − for center wear.
[0047]
(3) Ride Comfort Test tires were mounted on a large bus, and the ride comfort when the general road was run for 3 hours from the initial stage under constant volume conditions was evaluated according to the occupant's sensation in the following seven stages. Evaluation is an average of 100 crew members.
◎ --- Good.
○ S --- Good but soft.
○ H --- Good but slightly lumpy.
ΔS --- not uncomfortable but too soft.
[Delta] H --- not uncomfortable, but irritating.
× S --- It is shaken from side to side and uncomfortable.
× H --- It is unpleasant with a craggy feeling.
[0048]
[Table 1]

[0049]
[Table 2]

[0050]
【The invention's effect】
Since the present invention is configured as described above, it is possible to appropriately ensure the bending at the time of loading, exhibit excellent ride comfort, and prevent excellent deformation by preventing permanent deformation due to temperature rise. It can be maintained for a long time. In addition, it is possible to eliminate the uncomfortable feeling by suppressing fluctuations in ride comfort with the passage of time. Further, the uneven wear resistance can be improved and the wear life can be improved.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing an embodiment of a tire set according to the present invention.
FIG. 2 is a diagram illustrating filling of a two-component mixed curing type resin material.
FIG. 3 is a diagram showing a shape of a ground contact surface when a normal load is applied.
[Explanation of symbols]
2 Tread portion 3 Side wall portion 4 Bead portion 5 Bead core 6 Carcass 7 Breaker layer 10 Tire 11 Rim 12 Filler C Tire equator F Ground surface shape H Tire lumen TE Tread ground edge

Claims (4)

A toroidal tire comprising a carcass extending from the tread portion through the sidewall portion to the bead core of the bead portion and a breaker layer disposed inside the tread portion and outside the carcass, a rim for assembling the tire rim, And a non-foaming filler that is filled in a tire lumen surrounded by the tire and the rim.
The filler has a complex elastic modulus E * at 70 ° C. of 0.4 to 2.0 Mpa and a tangent loss (tan δ) of 0.01 to 0.08,
The shape of the contact surface when a normal load is applied is such that the ratio Lc / Ls between the contact length Ls in the circumferential direction at the tread contact edge and the contact length Lc at the tire equator is 0.88 to 0.98. A tire set characterized by that. The tire set according to claim 1, wherein the tire is a heavy duty radial tire, and the filler is made of urethane resin. 3. The carcass is made of one carcass ply using a steel carcass cord, and the breaker layer is made of two or more breaker plies using a steel breaker cord. The described tire set. The tire set according to any one of claims 1 to 3, wherein the contact surface has a shape in which the contact length L in the circumferential direction gradually decreases from the tire equator toward the tread contact edge.

Images