JPH0781320A - Pneumatic radial tire - Google Patents

Abstract

PURPOSE:To provide a pneumatic tire that is easy of a tread change by unifying a vulcanized tire base substance equipment with a carcass at an angle approximating to a right angle with the equator and a vulcanized annular tread ring equipped with a belt layer at a small angle of a belt cord in relation to the equator by means of expansion to the outside. CONSTITUTION:A tire base substance 7 is provided with a bead part 3 and a sidewall part 4, and a tread ring 6 is detachably attached onto the outer circumferential surface of a tread bottom part 9, thereby constituting a tread part 5 jointly. A carcass 10 is installed in this tire base substance 7, arranging a carcass cord to the equator as far as 70 to 90 degrees, and a fiber reinforced part is formed at the outside, setting down it to the outer circumferential surface. A belt layer 15 hooping the tire base substance 7 wrapped the tread ring 6 in the circumferential direction, and a belt cord is arranged at a shallow angle of less than 30 degrees to the equator. In this constitution, the tire base substance 7 is inflated by internal pressure changed while the tread ring is restrained from its outer diametral growth, so that both of them are connected as one 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 tire that can inexpensively supply various tread patterns according to the purpose of use and the like, and that 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]

In order to achieve the above object, the pneumatic tire of the present invention has a vulcanized annular tread ring and a tread portion of the tire by attaching the tread ring to the outer peripheral surface. A vulcanized tire base having an eggplant tread bottom, the tire base being folded back around the bead core of the bead portion from the tread bottom portion to the sidewall portion, and the carcass cord being 70 to 90 relative to the tire equator. The tread ring includes a belt layer in which belt cords are arranged at an angle of 30 degrees or less with respect to a tire equator, and the tread ring is expanded radially outwardly of the tire base body by internal pressure filling. It is integrally connected to the tire base body.

[0008]

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. Since the tire base does not have a belt layer, it expands like a rubber ball due to the internal pressure of filling, while the tread ring is not stretched in the radial direction by the belt layer. Therefore,
Due to the filling internal pressure, a strong pressure contact force is generated between the tread bottom and the tread ring, whereby both are firmly and integrally connected without slippage, and the same steering performance as that of the conventional tire can be exhibited.

On the other hand, a tire has
The tread ring can be easily removed from the tire base.
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.

Furthermore, 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 is improved as compared with the conventional tire rehabilitation, and the repeated use is possible.

[0011]

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 Y1 assembled to a standard rim R and filled with standard internal pressure. In this example, the pneumatic tire 1 has a flatness ratio of 80% which is a ratio of the tire height to the tire width. It is formed as a radial tire for the following passenger cars.

In FIG. 1, a tire 1 has a bead core 2
With a pair of bead portions 3, sidewall portions 4 extending outward from each bead portion 3 in the radial direction of the tire, and a tread pattern P is provided on the outer peripheral surface so as to join the outer ends of the sidewall portions 4. And a tread portion 5.

Further, the tire 1 is, as shown in an enlarged scale 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 body 7 has a toroidal shape in which the outer ends of the sidewall portions 4 extending from the bead portion 3 are joined by a tread bottom portion 9 having a small thickness. By attaching the tread ring 6 detachably, the tread bottom 9 and the tread ring 6
Cooperate with each other to form the tread portion 5.

The tire base 7 has a tread bottom 9
From the inside to the outside around the bead core 2 through the sidewall portion 4 and the carcass 10
A bead apex 11 made of hard rubber having a substantially triangular cross section which extends from the bead core 2 outward in the tire radial direction and is interposed between the main body portion and the folded portion of the tire base body 7 to increase the strength of the tire base body 7 and the tire rigidity. Improve.

The carcass 10 is formed by at least one carcass ply 10A in which carcass cords are arranged at an angle of 70 to 90 degrees with respect to the tire equator, and in this example, one carcass ply. The carcass cords are polyester fiber cords. Is used. 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.

The outer peripheral surface 9S of the tread bottom portion 9 has a main surface portion 9S1 extending substantially parallel to the carcass 10 and an angle θ1 of 30 degrees or more, preferably 45 degrees or more with respect to the tire axial direction line from both ends 9e thereof. And a locking surface portion 9S2 extending upward with an inclination toward the outer side in the tire axial direction.

Further, the outer peripheral surface 9S of the tread bottom portion 9 must 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. In this example, in order to further prevent damage to the carcass due to rubbing with the tread ring 6, a fiber reinforcing layer 12 is formed on the outer side of the carcass 10, and the outer surface of this layer 12 forms the outer peripheral surface 9
Constitutes S.

Here, the fiber reinforcing layer 12 is, in this example,
For example, short fibers made of organic materials such as nylon, rayon, polyester, aromatic polyamide, and carbon fibers, and short fibers made of inorganic materials such as glass fibers, metal fibers, whiskers, and boron are mixed in the rubber to contain short fibers. A rubber layer is used.

Further, as the fiber reinforcing layer 12, other than the above, organic,
It is possible to use a comb-shaped fabric material in which inorganic fiber cords are arranged in parallel to each other in rubber, and a woven fabric material in which fiber cords are woven as warp and weft threads.

The fiber reinforcing layer 12 is provided on at least the main surface portion 9S1. The tread ring 6 is a vulcanized annular body in which a tread pattern P is formed on the outer peripheral surface, and the inner periphery of the tread ring 6 is tightly joined and attached to the outer peripheral surface 9S of the tread bottom portion 9. The surface 6S is formed as a curved surface along the outer peripheral surface 9S. That is, the inner peripheral surface 6S
Includes an attachment surface portion 6S1 that matches the main surface portion 9S1 and an engagement surface portion 6S2 that matches the locking surface portion 9S2. The locking surface portion 9S2 is tilted upward to incline the tread ring 6 in the tire axial direction. Misalignment is restricted.

Further, the tread ring 6 has a tough belt layer 1 which reinforces the tread portion 5 and enhances the rigidity thereof, and at the same time has the flatness of the tire base body 7 and tightens it.
5 is wound in the circumferential direction.

The belt layer 15 is formed of at least one, in this example, two inner and outer belt plies 15A and 15B. In each of the 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, and the belt cords cross each other, so that the rigidity of the belt layer 15 itself is increased. With
Suppresses circumferential expansion. Further, the belt layer 15 has an arc shape having a center on the equator of the tire 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 prevent the occurrence of puncture or the like and enhance the traveling safety.

In this embodiment, the band layer 16 and the fiber reinforcing layer 17 are provided on the outer side and the inner side of the belt layer 15 in the radial direction.

The band layer 16 is at least the belt layer 15.
By covering the outer end of the tire in the axial direction, the outer diameter growth of the outer end of the belt layer 15 during high speed running is prevented.

Therefore, the band layer 16 is formed as a cord array in which band cords made of organic fiber such as nylon are arranged at an angle of 5 degrees or less with respect to the tire equator. In this example, the band layer 16 is the belt layer 1
5 has a wide width formed by spirally winding a band cord from one end to the other end of the belt 5, and more effectively restrains the belt layer 15 over the entire width, thereby suppressing the outer diameter growth of the belt layer 15. To do. 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 fiber reinforcement layer 17 is the same as the fiber reinforcement layer 12 described above.
Similar to the above, a reinforcing layer using an organic or inorganic fiber material,
The belt cord is covered by being disposed inside the belt layer 15 to prevent damage to the belt layer 15 due to rubbing with the tread bottom 9. In this example, a woven fabric material of polyester fiber cord is used as the fiber reinforcing layer 17, and a rubber material such as a topping rubber and a tread rubber of the woven material forms the inner peripheral surface 6S to form the reinforcing layer. Prevents friction damage between fibers between 12 and 17.

In order to prevent rubbing between the tread ring 6 and the tire base 7, the fiber reinforcing layer 12 or 17 is provided on at least one surface, that is, the surface 9S or 6S.

However, as shown in FIG. 3, the tread ring 6 is placed on the outer peripheral surface 9S of the tread bottom 9 of the tire base body 7 prior to the internal pressure filling of the tire base body 7, more preferably prior to the rim assembly. Then install. After that, a standard internal pressure is filled into the inner cavity of the tire base body 7. Tire base 7
Since the belt layer 15 is not provided, it greatly expands like a rubber ball, and at this time, the non-stretchable tread ring 6 having the belt layer 15 and the tire base body 7 have a strong pressure contact force and are integrally connected. . Further, since the tire base body 7 is tightened by the tread ring 6 upon expansion, it is constrained to the tire shape based on the theory of natural cross-sectional shape, and can exhibit excellent running performance equivalent to that of the conventional flat radial tire.

Further, the tread ring 6 and the tire base 7 are
As described above, since the tires are integrally connected by the inflation of the inner pressure, the tread ring 6 can be easily detached from the tread bottom 9 without using a special tool or the like. It enables replacement with a new tread ring without wear and with a tread ring having another tread pattern such as for a snowy road. 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 formed as independent bodies, respectively.
No. 4 tires and tread rings of this example and conventional tires integrally molded by vulcanization were prototyped based on the specifications shown in Table 1, and the steering stability performance of each tire and the tread ring and tire base body during running were The occurrence of slippage during the period was tested.

[0033]

[Table 1]

In the steering stability performance test, the driver's feeling when the vehicle was mounted on an actual vehicle under standard internal pressure and the vehicle actually traveled on a dry road surface was evaluated by a 5-point method. In addition, the sliding test was carried out by setting the tire internal pressure to 3.0 ksc.
Change to 1.9 ksc, 1.4 ksc, 1.0 ksc, and repeat the running cycle of 80 km / h (straight ahead) + 20 km / h (U-turn) to drive the tread ring and the tire base body when running a distance of 50 km. 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 are firmly and integrally connected to each other under the condition of 73% standard internal pressure or higher, whereby the same steering performance as the conventional one can be exhibited.

[0036]

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 9 tread bottom 9S outer peripheral surface 10 carcass 12 fiber reinforcement layer 15 belt layer 16 band layer

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. The tread ring includes a carcass that is folded back around the bead core of the bead part from the bottom of the tread to the sidewall part and arranged at an angle of 70 to 90 degrees with respect to the tire equator. Against 3
A pneumatic radial tire comprising a belt layer arranged at an angle of 0 degrees or less and being integrally connected with the tire base body by expansion of the tire base body in a radial direction outward by filling with an internal pressure. 2. The tread ring has a band cord, which covers at least the outer end of the belt layer in the tire axial direction and which is made of organic fiber, at an angle of 5 degrees or less with respect to the tire equator. 2. The pneumatic radial tire according to claim 1, further comprising a band layer arranged in accordance with claim 1. 3. The pneumatic radial tire according to claim 1, wherein the tire base has an outer surface of the tread bottom portion covered with a fiber reinforcing layer for protecting the carcass.