JP2001010306A - Bicycle tire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an open side type bicycle tire to improve cut resistance at a tire flank and besides be excellent in running performance. SOLUTION: In an open side type bicycle tire 1 having a carcass exposed at the side wall part 3 of a tire, the tire is provided with a reinforcing material 7 and a carcass 5 consists of a continuous part 5a and folded part 5b, and the length of the folded part 5b is in a range of 50-90% of a distance between the two bead parts 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bicycle tire, and more particularly to a bicycle tire of an open side type tire having excellent cut resistance in a sidewall portion and maintaining sufficient running performance.

[0002]

2. Description of the Related Art There are various types of tires used as bicycle tires. Among them, there is an open side type tire as a tire having a structure suitable for reducing the weight of the tire.

A bicycle tire has a structure in which a bead wire is included in a carcass layer in which a thin rubber is adhered to a surface of a woven fabric such as a sume, folded, and a tread rubber is laminated. The tread rubber is a rubber layer which is a relatively thick rubber layer, has excellent wear resistance, and has a certain level of friction with the road surface.

[0004] In the case of such a tire in which the tread rubber is laminated on almost the entire surface of the carcass, the tire is protected by the tread rubber, is resistant to external impact and piercing of sharp objects, and is punctured. It can be said that the tire is unlikely to cause such problems. However, in terms of weight, the amount of tread rubber increases,
It was disadvantageous and I had to use heavy tires.

On the other hand, in the case of an open-side type tire, the tread rubber is provided only at a portion in contact with the road surface of the tire. For this reason, open-side type tires can be reduced in weight and are suitably used, for example, for racing tires.

[0006]

However, in the case of the open side type tire, the amount of rubber adhered to the side surface is small, and it is certain that the tire is inferior in cut resistance and the like. For example, as shown in Japanese Patent Application Laid-Open No. Hei 10-230706, a rope obtained by twisting a predetermined number of monofilaments as a woven rope used for a carcass is used to increase the reinforcing property of the carcass and improve the cut resistance of the tire. Have been proposed.

[0007] With the above-described technology, it was possible to improve the performance such as cut resistance and abrasion resistance without deteriorating the running performance of the tire, but it can be said that the improvement is focused on maintaining the running performance. Sufficient cut resistance and rubbing resistance could not be obtained.

On the other hand, there has been proposed a method in which a reinforcing material made of a fabric other than the carcass is arranged in a state of being laminated on the carcass, and the reinforcing property is enhanced by plying up a fabric layer on the tire side surface.

[0009] By laminating the reinforcing material, the side surface of the tire can be strengthened and the cut resistance can be improved to make the tire hard to puncture. Performance had to be sacrificed considerably. In particular, the ply-up in the tread portion increased the rolling resistance and was a major cause of the decrease in running performance.

[0010] Therefore, there has been a demand for a bicycle tire having high cut resistance and high running performance. The present invention solves the above-described problems, increases the weight of the tire, or without significantly reducing the running performance, improves the cut resistance on the side of the tire, does not easily cause puncture, and is an open-side type tire. The aim is to provide bicycle tires that are lightweight and have a long life.

[0011]

According to the present invention, in order to achieve the above object, a pair of bead portions are wrapped with a carcass made of a fabric covered with a rubber layer at intervals. The carcass forming the carcass is extended to the sidewall portion and the tread portion of the tire, and at least the tread portion is laminated with tread rubber,
In a bicycle tire in which a one-layer reinforcing material made of a woven fabric covered with a rubber layer is arranged separately from a carcass from a tread portion to a sidewall portion, the carcass is folded back at a bead portion. That is, the ends of the two folded portions are not overlapped with each other, and the combined length of the two folded portions is in the range of 50 to 90% of the length between the two bead portions. Features.

As described above, the number of laminations in the tread portion including the reinforcing material is reduced by reducing the number of laminations in the tread portion including the carcass as two plies in the side wall portion and one ply in the tread portion, so that the sidewall portion is reinforced. As a result, the cornering force can be increased in terms of running performance, and the rolling resistance can be reduced, so that a bicycle tire with improved running performance can be obtained.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a specific embodiment of a bicycle tire 1 according to the present invention will be described with reference to the drawings. FIG. 1 is a perspective view of a bicycle tire 1 embodying the present invention, and FIG. 2 is a sectional view taken along line AA in FIG.

The bicycle tire 1 of the present invention is an open-side type tire and comprises a bead portion 2, a sidewall portion 3, and a tread portion 4.

The bead wire 2a in the bead portion 2 is made of a normal metal wire or an organic or inorganic fiber rope such as aromatic polyamide fiber, glass fiber, carbon fiber, etc., and has a diameter of about 0.1 to 0.5 mm. The bead wire 2 is formed by a carcass 5 made of a fabric covered with a rubber layer.
a is wrapped. The carcass 5 has a two-layer structure in the sidewall portion 3 of the tire, and the carcass 5 has a single layer in a tread portion 4 which is a ground contact portion of the tire.

A tread rubber 6 is integrally laminated on the surface of the ground contact portion of the tire. The type of the tire to which the present invention is applied is an open side type, and the tread rubber 6 is usually provided only on the ground contact portion of the tire, but has the tread rubber 6 that slightly covers the side surface of the tire. Even if the tire has a portion where the carcass 5 is exposed on the side surface of the tire, the tire has a problem that the life of the tire is shortened due to deterioration of the portion.

A reinforcing member 7 for reinforcing the tire is disposed. In the example shown in FIG. 2, the reinforcing member 7 is disposed between the carcass 5 and the tread rubber 6 of the tire.

In order to improve the cut resistance of the tire, it is preferable to laminate the carcass and the reinforcing material in multiple layers. However, in terms of running performance, the multilayer laminate is not preferable because it increases the weight or is preferable. In particular, the rolling resistance is increased particularly by multilayering the tread portion, which is a major cause of a decrease in running performance.

Therefore, in the present invention, as shown in the development view of the carcass 5 in FIG. 3, the carcass 5 is in a state in which the bead wire is wrapped by a pair of bead portions, and a continuous portion 5a extending over both bead portions and two It has a folded portion 5b. The two folded portions 5b do not overlap each other, and the lengths of the two folded portions 5b (L ₁ , L ₂
(L ₁ + L ₂ ) is 50 to 90% of the length (L ₀ ) between both bead portions 5.

By doing so, the carcass has two plies including the folded portion in the sidewall portion, and the carcass has become one ply without the folded portion reaching the tread portion. . Therefore,
Puncture resistance, such as cut resistance, can be improved in the sidewall portion without reducing the weight increase and without decreasing the running performance.

The length of the two folded portions 5b is
When less than 50% of the length between both bead portions, folded portion 5b
Thus, there is a problem that the effect of reinforcing the sidewall portion is small, the cut resistance of the tire side surface is insufficient, and the cornering force is reduced.
If it exceeds 90%, the ratio of covering the tread portion becomes too large, and there is a problem that the rolling resistance is increased, which is not preferable.

The material of the fabric constituting the carcass 5 and the reinforcing material 7 is a plain weave made of polyamide yarn, polyester yarn, aramid yarn, rayon, or cotton yarn, twill weave, or sudare weave. , A very thin rubber layer coated by a method such as friction, coaching, or gluing.

The carcass 5 is adhered to the above-mentioned woven fabric by resorcinol-formalin latex (RFL).
It is treated with a treatment liquid and coated with rubber. Reinforcement 7
Also, after pre-treating the woven fabric with an isocyanate compound or an epoxy compound, the fabric is subjected to an adhesive treatment with a resorcinol-formalin latex (RFL) treatment solution, and the strength of the reinforcing material 7 is increased by coating with rubber. By performing this pretreatment, the reinforcing material 7
Puncture resistance such as cut resistance and rub resistance. The arrangement form of the reinforcing member 7 is not limited to the example of FIG. 2, and may be arranged inside the folded carcass 5.

The isocyanate compound and the epoxy compound may be used not only as a pretreatment for the RFL treatment but also mixed with the RFL treatment solution and adhered to the fabric simultaneously with the RFL treatment. It is preferable that the solid content adhesion amount to the fiber amount of the reinforcing material 7 is 0.5 to 20%.

If the solid content of the isocyanate compound or epoxy compound is less than 0.5%, the effect of reinforcing the woven fabric is small, and sufficient cut resistance and rubbing resistance cannot be obtained even for a tire. If it exceeds 20%, the reinforcing effect is extremely excellent, but the hardness of the fabric is too high, and the running performance such as rolling resistance and cornering force is undesirably reduced.

Examples of the isocyanate compound which can be used in the present invention include 4,4'-diphenylmethane diisocyanate, tolylene-2,4-diisocyanate, and polyaryl polyisocyanate. This isocyanate compound is also used by being mixed with an organic solvent such as toluene and methyl ethyl ketone.

Examples of the epoxy compound include polyhydric alcohols such as ethylene glycol, glycerin and pentaerythritol, reaction products of polyalkylene glycols such as polyethylene glycol and halogen-containing epoxy compounds such as epichlorohydrin, resorcinol, bis (4 (Hydroxyphenyl) dimethylmethane, a reaction product with a polyhydric phenol such as a phenol-formaldehyde resin, a resorcin-formaldehyde resin, or a halogen-containing epoxy compound. This epoxy compound is used by being mixed with an organic solvent such as toluene and methyl ethyl ketone similarly to the isocyanate compound.

The RFL treatment solution used in the present invention is a latex containing one or more of styrene-butadiene rubber (SBR) -based latex, styrene-butadiene-vinylpyridine terpolymer (VP), natural rubber and the like. Blends can be used.

Natural rubber (NR), ethylene propylene rubber (NR) and rubber used for the carcass 5 and the reinforcing material 7 to be coated with a means such as friction, coating and gluing after being subjected to an adhesive treatment are used. E
PDM), styrene-butadiene rubber (SBR), nitrile rubber (NBR), butyl rubber (BR), chloroprene rubber (CR), and the like.

[0030]

EXAMPLES Next, running performance (rolling resistance, cornering force) using tires according to the present invention and tires outside the scope of the present invention, including conventional tires, was used.
And a test comparing cut resistance on the side of the tire.

Example 1 A carcass obtained by adhering unvulcanized natural / SBR rubber to a thickness of 0.1 mm on a Sudare woven canvas in which nylon 420D / 1 yarn was woven at a density of 130 yarns / 5 cm was used. Use, wrap a bead made of piano wire,
Unvulcanized natural / SB on Sudare woven canvas similar to carcass
R rubber coated to a thickness of 0.1 mm as a reinforcing material is laid on a carcass in the form of FIG. 1 and then uncured natural / S
A tread rubber made of BR rubber was laminated, set in a mold, and vulcanized. The combined length of the two folded portions of the carcass is set to be 55% of the length between both bead portions.

As a side cut resistance test, an acute angle blade (NT cutter: L300) 11 was placed on the lower surface of an autograph (AG-5000) 10 manufactured by Shimadzu Corporation using the obtained tire (700 × 23C). Then, as shown in FIG. 4, the tire 12 was set, and the sharp edged blade was moved in the direction of the arrow to hit the sidewall portion of the tire. Then, the strength of the tire to puncture was measured.

Further, the rolling resistance and the cornering force were measured with a road surface tester manufactured by Daiwa Seiko. The test condition at this time is that the tire internal pressure is 800 kP.
a, the load at the time of rolling resistance measurement is 40 kg,
Speed 40km / h, load at cornering force measurement 40kg, speed 30km / h, camber angle 20
° and a slip angle of 2 °. Table 1 shows the results of the above tests.
Shown in

Example 2 A tire was manufactured in the same manner as in Example 1 except that the combined length of the two folded portions of the carcass was 70% of the length between both bead portions. In the same manner as in Example 1, the tire strength and running performance until the tire punctured were measured. Table 1 shows the results.

Example 3 A tire was manufactured in the same manner as in Example 1 except that the combined length of the two folded portions of the carcass was set to 85% of the length between both bead portions.
In the same manner as in Example 1, the tire strength and running performance until the tire punctured were measured. Table 1 shows the results.

[Comparative Example 1] The length obtained by combining the two folded portions of the carcass in Example 1 was 4 which was the length between both bead portions.
Except for 0%, the same tire as in Example 1 was produced. Example 1
In the same manner as in the above, the tire strength and running performance up to puncture were measured. Table 2 shows the results.

Comparative Example 2 The same tire as in Example 1 was produced except that the combined length of the two folded portions of the carcass in Example 1 was 95% of the length between both bead portions. In the same manner as in Example 1, the strength and running performance until the tire punctured were measured. Table 2 shows the results.

[Comparative Example 3] In Example 1, the two folded portions of the carcass were extended to the tread portion, and both were turned to 1
A tire as shown in FIG. 5, which was the same as in Example 1, except that the tire was wrapped with a width of 5 mm and no reinforcing material was provided. In the same manner as in Example 1, the strength and running performance until the tire punctured were measured. Table 2 shows the results.

[0039]

[Table 1]

As can be seen from Table 1, in Examples 1 to 3, excellent results were obtained in that the cut resistance of the tire side surface was excellent, the rolling resistance was low, and the cornering force was high in running performance. .

On the other hand, in Comparative Example 1, since the length of the folded back portion of the carcass was short, the sidewall portion could not be sufficiently reinforced, resulting in inferior cut resistance of the tire side surface.

Also, in Comparative Example 2, the carcass folded portion is long and the tread portion is largely covered, but the running performance such as cornering force and rolling resistance is inferior, although there is no problem in cut resistance. Has become.

In Comparative Example 3, a conventional carcass wrapped at the tread portion and a tire having no reinforcing material was used. However, since no reinforcing material was provided, the tire was inferior in cut resistance. No good results have been achieved in the cornering force.

[0044]

As described above, according to the first aspect of the present invention, a carcass forming a carcass is formed by wrapping a pair of bead portions with a carcass made of a fabric covered with a rubber layer at intervals. And a tread rubber is laminated on at least the tread portion, and a one-layer reinforcing material made of a fabric covered with a rubber layer is applied separately from the carcass to the tread portion and the sidewall portion. In the arranged bicycle tire, the carcass has a continuous portion and two folded portions in a state of being folded at a bead portion, and ends of the two folded portions are not overlapped with each other, and the lengths of the two folded portions are different. Is in the range of 50 to 90% of the length between the bead portions.

As described above, the carcass is reduced to two plies in the side wall part and to one ply in the tread part, thereby reducing the number of laminations in the tread including the reinforcing material. Therefore, the side wall is reinforced. As a result, the cornering force can be increased in terms of running performance, and the rolling resistance can be reduced, so that a bicycle tire with improved running performance can be obtained.

[Brief description of the drawings]

FIG. 1 is a perspective sectional view of a bicycle tire.

FIG. 2 is a sectional view of a bicycle tire.

FIG. 3 is a developed side view of the carcass.

FIG. 4 is a schematic diagram showing the measurement of cut resistance.

FIG. 5 is a sectional view of a conventional bicycle tire.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Bicycle tire 2 Bead part 3 Side wall part 4 Tread part 5 Carcass 5a Folding part 5b Continuous part 6 Tread rubber 7 Reinforcing material

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI theme coat ゛ (reference) B60C 15/00 B60C 15 / 00GH

Claims (1)

[Claims] 1. A carcass forming a carcass is extended to a sidewall portion and a tread portion of a tire while a pair of bead portions are wrapped with a carcass made of a fabric covered with a rubber layer at intervals. In a bicycle tire in which at least the tread portion is laminated with tread rubber, and a one-layer reinforcing material made of a fabric covered with a rubber layer is arranged from the tread portion to the sidewall portion separately from the carcass, the carcass is a bead portion. In the folded state, it is composed of a continuous portion and two folded portions, and the ends of the two folded portions do not wrap, and the total length of the two folded portions is equal to the length between the two bead portions. 5 of length
A bicycle tire having a range of 0 to 90%.