JPH08150811A - Pneumatic radial tire - Google Patents

Abstract

PURPOSE: To make a tread rubber part freely removable from a tire base body by connecting a tread ring being equipped with a belt layer arranged with belt cords at specified angles integrally with the tire base body by means of an inflation of this base body due to the charging of internal pressure. CONSTITUTION: A tire base body 7 is turned over around a bead core 2 of a bead part 3 by way of a sidewall part 4 from a tread bottom part 9, while it forms a carcass 10 with a carcass cord of radial arrangement and a peripheral surface of the tread bottom part 9, and it is provided with a support layer 12 to be formed by a rubber composition of 0.5 to 5mm in thickness. A tread ring 6 is equipped with a belt layer 15 arranged with belt cords at an angle of less than 30 degrees to a tire equator, and further it is integrally connected to the tire body 7 by means of its inflation to the outside in the radial direction of the tire base body 7 due to the charging of internal pressure. With this constitution, a tread rubber part is made freely removable from the tire base body.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention allows the tread rubber portion to be freely attached and detached from the remaining tire body.
For example, the present invention relates to a pneumatic radial tire that can inexpensively provide various tread patterns according to the purpose of use and the like, and can repeatedly use the tire main body when the tread rubber is worn away, which is useful for effective use of resources.

[0002]

2. Description of the Related Art In recent years, in a tire having a radial structure in which the strength life of the carcass is higher than the wear life of the tire,
From the viewpoint of effective use of resources, some tires are being rehabilitated by replacing worn tread rubber and reusing it.

Conventionally, a tire is one in which a tread rubber and the remaining tire base are integrally bonded by vulcanization. Therefore, in tire retreading, a base tire obtained by removing the tread rubber by buff cutting or the like is used. An unvulcanized tread rubber material is attached, and then vulcanized and molded in a mold to reintegrate.

[0004]

However, as mentioned above, the cost for retreading of the tire is high because it requires many work steps such as buff cutting, sticking of rubber, vulcanization and molding in the mold. There's a problem. Therefore, for relatively inexpensive tires, such as tires for passenger cars and tires for light trucks, which account for approximately 60% or more of the total number of tires, the price difference from new tires becomes extremely small, which makes it difficult to economically implement them. It is not possible to achieve effective utilization of resources.

On the other hand, in the case of this type of tire, in order to sufficiently exhibit the running performance of a vehicle having high performance and high output, for example, for wet, dry, off-road,
Tread patterns with various performances are provided according to the purpose of use, such as for ice and snowy roads, and the road surface environment. As a result, the number and types of tires increase, increasing the economic burden on the user, and further hindering the effective use of resources such as increasing the number of unused tires and unnecessary tires.

The present invention is based on the fact that the tread rubber portion can be freely attached and detached from the tire base body.
It is an object of the present invention to provide a pneumatic radial tire that simplifies the reuse of tires, can supply various tread patterns at low cost, and can solve the above problems.

[0007]

SUMMARY OF THE INVENTION The present invention provides a vulcanized annular tread ring and a vulcanized tire base having a tread bottom that forms the tread portion of the tire by attaching the tread ring to the outer peripheral surface. The tire base is composed of a carcass having a carcass cord of a radial arrangement and being folded back around the bead core of the bead part from the tread bottom part to the sidewall part, and forming the outer peripheral surface of the tread bottom part with a rubber thickness. 0.
The tread ring includes a belt layer in which belt cords are arranged at an angle of 30 degrees or less with respect to the tire equator, and the support layer is formed by a rubber composition having a thickness of 5 to 5 mm. The pneumatic radial tire is characterized in that it is integrally connected to the tire base by expansion of the tire base outward in the radial direction.

The tread ring has a belt-shaped belt-shaped ply in which one cord or a plurality of cords are aligned and embedded in topping rubber on the outer side in the radial direction of the belt layer, and is spiraled at a small angle to the tire equator. At least one or more jointless band layers formed by winding can be provided.

Further, the tire base body may be provided with a reinforcing layer composed of one or more plies in which cords are arranged in the tire axial direction, on the outer side in the radial direction of the carcass.

[0010]

The tire is divided into a tire base having a carcass and a tread ring for forming a tread on the outside thereof,
Each of these is configured as a vulcanized independent body. The tire base body expands like a rubber ball by the filling internal pressure, and the tread ring includes a belt layer in which belt cords are arranged at an angle of 30 degrees or less with respect to the tire equator. Therefore, it is not stretched in the radial direction. Therefore, a strong pressure contact force is generated between the tread bottom portion and the tread ring due to the filling internal pressure, whereby both are firmly and integrally connected without causing slippage, and,
Since the tread ring has the belt layer and the jointless band layer, it is possible to prevent excessive shape change of the tire base and suppress variations in tire performance due to incorporation of the tread ring, similar to conventional tires. Maneuverability can be demonstrated. Furthermore, by providing a reinforcing layer composed of one or more plies in which cords are arranged in the tire axial direction on the outside of the carcass in the radial direction of the tire base, the carcass in the tread portion can be reinforced more reliably, and running safety is maintained. sell.

On the other hand, in the tire of the present application, the tread ring can be easily removed from the tire base body by discharging the filling internal pressure. Therefore, for example, when the tread surface is worn or when traveling on an ice / snow road surface, the user can freely replace the new tread ring without wear and the tread ring having the tread pattern for the ice / snow road. As a result, wasteful disposal of the tire itself, unnecessary increase in types, etc. can be prevented, resources can be effectively utilized, and tread patterns with various performances can be provided at low cost.

Moreover, since the tire base body to be reused can be managed by the user himself, the fatigue damage state of the carcass can be grasped, the reliability can be improved as compared with the conventional tire rehabilitation, and the repeated use is possible.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows a pneumatic radial tire 1 (hereinafter referred to as tire 1
Shows a meridional section of a tire in a state where it is assembled to a standard rim R and filled with standard internal pressure.
Is a flatness ratio of 8 which is the ratio of tire height to tire width.
It is formed as a radial tire for passenger cars of 0% or less.

In FIG. 1, a tire 1 includes a pair of bead portions 3 and 3 each having a bead core 2 and 2, sidewall portions 4 and 4 extending outward from the bead portions 3 and 3 in the tire radial direction, and And a tread portion 5 in which the outer ends of the sidewall portions 4 and 4 are joined together and a tread pattern P is recessed on the outer peripheral surface.

Further, the tire 1 is, as shown enlarged in FIG.
The tread ring 6 and the tire base 7, which are the remaining portion of the tread ring 6 and the radial outside of the tread portion 5, are formed as vulcanized independent bodies.

The tire base 7 has a toroidal shape in which the outer ends of the sidewalls 4 and 4 extending from the beads 3 and 3 are joined by a tread bottom 9 having a small thickness, and the outer peripheral surface of the tread bottom 9 is formed. By detachably attaching the tread ring 6 on 9S, the tread bottom portion 9 and the tread ring 6 cooperate to form the tread portion 5.

The tire base 7 has a tread bottom 9
A carcass 10 which is folded back from the inside to the outside around the bead cores 2 and 2 through the side wall portions 4 and 4 is provided, and the side wall portions 4 and 4 are provided on the outer side in the radial direction of the carcass 10. Sidewall rubber 4 to be formed
A support layer 12 that spans between the radially outer ends of A and 4A and that forms the outer peripheral surface 9S of the tread bottom 9 is provided.

The carcass 10 is formed by one or more carcass plies 10A in which the carcass cords are radially or semi-radially arranged at an angle of 70 to 90 degrees with respect to the tire equator C, and in this example, one carcass ply 10A. A polyester fiber cord is used as. Other than the carcass cords, organic fiber cords such as nylon, rayon and aromatic polyamide, and metal fiber cords such as steel may be used depending on the required tire performance.

A bead apex 11 made of hard rubber extending from the bead core 2 outward in the radial direction of the tire and made of hard rubber having a substantially triangular cross section is interposed between the main body of the carcass 10 and the folded-back portion. Reinforces the portion 4 to improve the lateral rigidity of the tire.

The outer peripheral surface 9S of the tread bottom 9 extends substantially parallel to the carcass 10 and slightly outward in the radial direction, and both ends thereof are formed by the sidewall rubbers 4A and 4A. It smoothly connects to the outer surface.

The outer peripheral surface 9S of the tread bottom 9 is required to be completely covered without exposing the carcass cord in order to prevent water and the like from entering the carcass cord and to enhance the airtightness of the tire. Therefore, in this example, in order to further prevent damage to the carcass due to rubbing with the tread ring 6, the support layer 12 that supports the tread ring 6 is formed outside the carcass 10, and the outer surface of the support layer 12 is The outer peripheral surface 9S is configured.

The support layer 12 has a rubber thickness of 0.5 to 5 mm,
More preferably, it is composed of a rubber composition of 2 to 4 mm, and its hardness is 60 to 96 degrees of JIS A hardness and its elastic modulus is 20 to
It is preferably in the range of 50 kgf / cm ² .

A reinforcing layer 14 made of an organic material such as nylon or polyester may be provided on the outer side of the carcass 10 in the radial direction and on the inner side of the support layer 12. The reinforcing layer 14 is composed of one ply in which cords are arranged in the same direction as the carcass cord or two plies in which cords are arranged at an angle of 30 ° to 90 ° with respect to the tire equator C. Can be reinforced by the tread bottom portion 9 of the tire base 7 to improve puncture resistance and the like.

The reinforcing layer 14 can also be formed by using one or more plies in which cords are arranged substantially in the axial direction of the tire. In this case, since the cord of the ply forming the reinforcing layer can be oriented substantially parallel to the carcass cord, the lateral rigidity of the tread bottom 9 of the tire base 7 can be increased.

The tread ring 6 is a vulcanized annular body having a tread pattern P formed of a tread groove G formed on the outer peripheral surface, and the outer peripheral surface 9S of the tread bottom 9 is formed.
The inner peripheral surface 6 so that it can be attached tightly and tightly
S is formed by a curved surface along the outer peripheral surface 9S. That is, the inner peripheral surface 6S has outwardly facing surfaces 9S1 and 9S1 facing both ends in the tire axial direction of the outer peripheral surface 9S at both ends in the tire axial direction.
Is provided with the downwardly inclined blade surface portions 6S1 and 6S1, by which the tread ring 6 is restrained from being displaced in the tire axial direction.

The tread ring 6 includes a belt layer 1
5 is provided, and in the present embodiment, a jointless band layer 16 is disposed on the outer side in the radial direction of the belt layer 15 in order to prevent lifting of the belt layer 15 during high speed running.

At least one belt layer 15 is provided,
In this example, the inner and outer two belt plies 15A and 15B are formed. In each of the belt plies 15A and 15B, high-strength belt cords are arranged at a shallow angle of 30 degrees or less with respect to the tire equator C, and the belt cords cross each other. This increases the rigidity of the tread ring 6.

The belt layer 15 has an arcuate shape having a center on the tire equator C and extending substantially parallel to the outer peripheral surface (tread surface) of the tread ring 6, and the belt width extends over substantially the entire length of the tread width.

Further, as the belt cord, a metal fiber cord such as a steel cord is preferably used in order to protect the carcass 10 to prevent the occurrence of punctures and enhance the safety of traveling.

In this example, the jointless band layer 16 is provided on the outer side of the belt layer 15 in the radial direction. The jointless band layer 16 covers at least the outer end of the belt layer 15 in the axial direction of the tire to prevent the outer diameter of the outer end of the belt layer 15 from growing at a high speed.

Therefore, the jointless band layer 16
Is an organic fiber such as aromatic polyamide.
It is formed by spirally winding a cord or two or three cords that are aligned and buried in a topping rubber at a small angle of 5 degrees or less with respect to the tire equator C. In this example, the jointless band layer 16
Is a wide width formed by spirally winding one cord from one end to the other end of the belt layer 15, and the belt layer 15 is more effectively constrained over the entire width, so that the belt layer 15 Suppresses the outer diameter growth of. As a result, the deviation between the tread ring 6 and the tire base body 7 due to the outer diameter growth during high-speed traveling is prevented.

The jointless band layer 16 may be formed by hollowing out so as to cover only the outer end portion of the belt layer 15 in the tire axial direction.

As shown in FIG. 3, however, prior to the internal pressure filling of the tire base body 7, and more preferably, prior to the rim assembly, on the outer peripheral surface 9S of the tread bottom portion 9 of the tire base body 7,
Place the tread ring 6 and attach it. After that, a standard internal pressure is filled into the inner cavity of the tire base body 7. Tire base 7
Expands outward in the tire radial direction by the filling internal pressure, and at this time, the non-stretchable tread ring 6 having the belt layer 15 and the jointless band layer 16 and the tire base body 7 have a strong pressure contact force and are integrally formed. In addition, it can be surely connected, and can exhibit excellent running performance equivalent to that of a conventional flat radial tire.

On the other hand, since the tread ring 6 and the tire base 7 are integrally connected by the tire expansion due to the internal pressure filling as described above, the tread ring 6 can be removed from the tread bottom 9 by discharging the internal filling pressure. This can be easily performed without using a special tool or the like, and allows the user to replace the tread ring with a new tread ring having no wear or tread ring having another tread pattern for ice and snow roads. As a result, the tire base body 7 can be repeatedly used, and it is possible to inexpensively provide tread patterns having various performances according to the purpose of use and the like while effectively utilizing resources.

(Specific example) Tire size 185 / 70R1 in which the tread ring and the tire base body are each formed as an independent body.
No. 4 tires of this example (Example products 1 and 2) and conventional tires (conventional products) in which the tread ring and the tire base were integrally molded by vulcanization were prototyped based on the specifications in Table 1, and the steering of each tire was performed. The stability performance and the occurrence of slippage between the tread ring and the tire substrate during running were tested.

[0036]

[Table 1]

In the steering stability performance test, the driver's feeling when the vehicle was mounted on an actual vehicle under the condition of standard internal pressure and the vehicle actually traveled on a dry road surface was evaluated by the 5-point method. In addition, the sliding test was carried out by setting the tire internal pressure to 3.0 ksc.
Change to 1.9ksc, 1.4ksc, and 1.0ksc, and repeat the running cycle of 80km / h (straight ahead) + 20km / h (U-turn). The gap was measured. Also, as a sliding test, the filling internal pressure is 1.9 ks.
The deviation between the tread ring and the tire base body was also measured when a slip angle of 5 degrees was applied under the conditions of c and a load of 400 kgf and the drum was run for 10 minutes.

As shown in Table 1, the tread ring and the tire base body are firmly and integrally connected to each other without causing a deviation even under the condition of 53% standard internal pressure, whereby the same steering performance as the conventional one can be exhibited.

[0039]

Since the pneumatic radial tire of the present invention is constructed as described above, the tread ring can be freely attached to and detached from the tire base body, various tread patterns can be provided at low cost, and the tire base body can be repeated. Can be used and resources can be effectively used.

[Brief description of drawings]

FIG. 1 is a meridional sectional view of a tire showing an embodiment of the present invention.

FIG. 2 is an exploded cross-sectional view of a tire showing a tread portion in an enlarged manner.

FIG. 3 is a schematic cross-sectional view illustrating a connection between a tread ring and a tire base body.

[Explanation of symbols]

 2 bead core 3 bead part 4 sidewall part 5 tread part 6 tread ring 7 tire base body 9 tread bottom part 9S outer peripheral surface 10 carcass 12 support layer 14 reinforcing layer 15 belt layer 16 jointless band layer G tread groove

Claims (3)

[Claims] 1. A vulcanized annular tread ring, and a vulcanized tire base body having a tread bottom portion forming a tread portion of a tire by attaching the tread ring to an outer peripheral surface thereof. A carcass having a carcass cord of radial arrangement and folded around the bead core of the bead part from the tread bottom part to the sidewall part, and a rubber composition having a rubber thickness of 0.5 to 5 mm and forming the outer peripheral surface of the tread bottom part. The tread ring has a belt layer in which belt cords are arranged at an angle of 30 degrees or less with respect to the tire equator, and the outer side in the radial direction of the tire base body by internal pressure filling. A pneumatic radial tire characterized in that it is integrally connected to a tire base body by expansion into a tire. 2. The tread ring comprises a belt-shaped belt-shaped ply in which one cord or several cords are aligned and embedded in a topping rubber at a small angle with respect to the tire equator on the outer side in the radial direction of the belt layer. The pneumatic radial tire according to claim 1, wherein at least one jointless band layer formed by spiral winding is provided. 3. The pneumatic radial according to claim 1, wherein the tire base body is provided with a reinforcing layer composed of one or more plies in which cords are arranged in the tire axial direction, on the outer side in the radial direction of the carcass. tire.