JP2014172585A - Safety tire and production method of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a safety tire which has no increase of weight compared with a safety tire using an air pouch, and is capable of improving balance of the tire, which increases no cost for attachment and detachment, and which can be produced with a simple appliance.SOLUTION: The safety tire comprises a protection sheet 9 for blocking a space part between a tire inner face and a rim into an inside space A1 and an outside space A2 in a state that a tire 1 is attached to the rim, namely in an attached posture, and tire inner pressure is filled to predetermined inner pressure. A width direction end part of the protection sheet 9 is jointed to a bead part inner face side of the tire 1 in an integrated state.

Description

  The present invention relates to a safety tire that can continue to run even when the internal pressure of the tire suddenly drops due to puncture or the like, and a method for manufacturing the safety tire.

  2. Description of the Related Art Conventionally, a run flat tire or a safety tire has been known that can safely continue running to a place where repair or reinforcement can be performed when the tire punctures while traveling. As a kind of safety tire, there is an air bladder (sac) containing pressurized air, and when the air inside the tire leaks due to puncture etc., the air bladder expands according to the pressure difference, and the tire There is known a tire that closes a damaged portion such as a puncture hole generated in the tire to prevent a decrease in internal pressure.

As an example, for example, Patent Document 1 describes a safety tire in which a ring-shaped air bladder is housed inside a tire having a tread, a sidewall, and a bead portion, and separately from the tire. ing.
In this safety tire, a reinforcing layer that is a composite of a nonwoven fabric and rubber is disposed on at least the outer periphery of the air bladder. When the tire punctures and the air leaks from the air, The diameter expansion deformation of the cormorant is controlled as expected, and the deformation is uniformly and smoothly performed over the entire circumference of the air bladder.

As described above, the conventional safety tire is provided with an air bladder inside the tire, so that even when the tire is punctured or the like, the vehicle can safely travel for a certain distance with the tire.
However, the following problems are pointed out at the same time for the safety tire provided with the air bladder.
(I) The air bladder is a structure that is attached to the rim flange of the tire using an attachment device. Therefore, the weight is increased by at least the mounting device, and therefore there is a possibility that the tire performance such as the tire balance is deteriorated.
(Ii) Installation of the air bladder to the rim flange takes time because it is attached to the outer rim, air bag, and inner rim, and the same time is required for removal. Therefore, the cost required for attachment / detachment increases.

JP 2002-166711 A

  The present invention has been made in view of the above-mentioned problems in a safety tire equipped with a conventional air bladder, and its purpose is to avoid the substantial increase in weight because no air bladder is used. An object is to provide a new safety tire that improves the balance of the tire, does not increase the cost for attaching and detaching, can ensure the function as a safety tire, and can be manufactured with simple equipment.

According to a first aspect of the present invention, there is provided a protective sheet for partitioning a space between the tire inner surface and the rim into an inner space and an outer space in a mounting posture in which the tire is mounted on the rim and the tire inner pressure is filled to a predetermined inner pressure. It is a safety tire which has the width direction edge part of the said protection sheet integrally joined to the bead part inner surface side of the tire.
The invention according to claim 2 is the safety tire according to claim 1, wherein the inner space and the outer space have the same internal pressure.
A third aspect of the present invention is the safety tire according to the first or second aspect, wherein the protective sheet is an inner liner composed of inner and outer layers.
The invention according to claim 4 is the safety tire according to claim 1 or 2, wherein the protective sheet is an inflatable rubber sheet composed of inner and outer layers that load-support the tire from the inner surface.
According to a fifth aspect of the present invention, there is provided a protective sheet that divides a space between the tire inner surface and the rim into an inner space and an outer space in a mounting posture in which the tire is mounted on the rim and the tire inner pressure is filled to a predetermined inner pressure. A method of manufacturing a safety tire comprising: a step of disposing an outer protective sheet on an inner protective sheet via a release sheet, and joining width direction ends of the inner and outer protective sheets; and the outer protective sheet A safety tire comprising: a step of joining both end portions in the width direction of the tire to a bead portion of the tire; a step of forming a raw tire by disposing a tire constituent member on the protective sheet; and a step of vulcanizing the raw tire. It is a manufacturing method.
According to a sixth aspect of the present invention, there is provided a protective sheet for partitioning a space between the tire inner surface and the rim into an inner space and an outer space in a mounting posture in which the tire is mounted on the rim and the tire inner pressure is filled to a predetermined inner pressure. A method of manufacturing a safety tire comprising a step of joining width direction ends of a protective sheet formed by joining the width direction end portions to a bead portion of a tire formed on a tube or a bag, and on the protective sheet. A method for producing a safety tire comprising a step of arranging a tire constituent member and molding a raw tire and a step of vulcanizing the raw tire.
The invention according to claim 7 is the method for manufacturing a safety tire according to claim 5 or 6, wherein the protective sheet is an inner liner made of an inner and outer layer.
The invention according to claim 8 is the method for manufacturing a safety tire according to claim 5 or 6, wherein the protective sheet is an inflatable rubber sheet composed of inner and outer layers that load-support the tire from the inner surface. Is the method.

According to the first aspect of the present invention, the function as a safety tire can be obtained without using the air bladder, and there is no substantial increase in weight. Therefore, the balance of the safety tire is improved, and the cost for attaching and detaching is increased. In addition, it is possible to provide a novel safety tire that can be manufactured by a conventional manufacturing facility.
According to the invention of claim 2, since the internal pressures of the inner space and the outer space are equal, the vehicle can travel with good balance during normal traveling.
According to the inventions of claims 3 and 7, since the protective sheet is constituted by the inner liner composed of the inner and outer layers, it can be manufactured by conventional equipment. Moreover, since tire air leakage is sealed with the inner layer of the inner liner, normal tire performance is not impaired.
According to the inventions of claims 4 and 8, since the protective sheet is composed of an inflatable rubber sheet composed of inner and outer layers that load-support the tire from the inner surface, it can be manufactured with conventional equipment in the same manner as the inner liner layer. Since the air leakage is sealed with the inner layer of the rubber sheet, normal tire performance is not impaired.
According to the fifth and sixth aspects of the present invention, since the safety tire can be manufactured with the conventional manufacturing equipment, the work for assembling the member for the safety tire (for example, air bladder) to the tire as in the past is unnecessary. . Therefore, man-hours can be reduced, and safety tires can be efficiently manufactured at low cost.

It is sectional drawing which shows the structure of the principal part of the tire which concerns on this embodiment, and shows the state before being filled with air between inner liner inner and outer layers. FIG. 2 is a view similar to FIG. 1 showing a state in which air is filled between inner and outer layers of the inner liner. It is a figure which shows typically shaping | molding of an inner liner in manufacture of the tire which concerns on this embodiment. It is a figure explaining the installation procedure of the air valve to the inner liner inner layer. FIG. 5A is a cross-sectional view of a main part for explaining a state at the time of occurrence of puncture of a tire according to the present embodiment, in which FIG. 5A is a state in which the internal pressure of the tire is reduced by puncture, and FIG. 5B is an expanded inner liner inner layer, It is sectional drawing which shows the state which plugged up the puncture hole, respectively.

  The safety tire of the present invention (simply referred to as a tire in the following description) is configured separately from the tire, like conventional air bladders, and saves the trouble of mounting together with the tire body on the tire rim. It is characterized in that an increase in weight is suppressed to improve the weight balance of the tire, and that a member that seals air leakage of the tire due to puncture or the like can be molded integrally with the tire constituent member.

Next, an embodiment of the tire of the present invention will be described with reference to the drawings.
FIG. 1 is a cross-sectional view showing a structure of a main part of a tire according to the present embodiment, showing a state before air is filled between inner liner inner and outer layers 9a and 9b, and FIG. 2 shows an inner liner inner and outer layer 9a. FIG. 9 is a view similar to FIG. 1 showing a state in which air is filled between 9b.
As shown in FIG. 1, the tire 1 has basically the same structure as a normal tire, for example, a radial tire for a passenger car.
That is, a tread 2 that is a ground contact surface of the tire 1, sidewalls 3 on both sides of the tread 2, a belt layer 4 disposed inside the tread 2, and a carcass 5 disposed inside the belt layer 4 The pair of bead cores 6 on both sides in the width direction of the tire, the bead filler 7 disposed between the main body 5a of the carcass 5 and the folded portion 5b around the bead core 6 on the outer side in the tire radial direction of the bead core 6, and the carcass 5 A chafer rubber 8 disposed inside the folded portion 5b, an inner liner 9 disposed along the inner surface of the carcass 5 from the inside of the chafer rubber 8, and the like.
In addition, it points out the part where the folding | returning part 5b of the carcass 5, the bead core 6, the bead filler 7, and the chafer rubber 8 exist, and is called the bead part of the tire 1, and the inner liner 9 is joined to the inner surface (tire inner surface) side of the bead part. Yes.

  The tire 1 of the present embodiment has the above-described configuration. The inner liner 9 is different from a conventional tire in that it has two layers (inner and outer directions in the radial direction of the tire here) (inner liner inner layer 9a and inner liner). Outer layer 9b). Here, the inner liner inner layer 9a and the inner liner outer layer 9b are joined only at their circumferential ends and not inside so that air can be filled between these layers. Therefore, by filling air between the inner liner inner and outer layers 9a and 9b, the inner liner inner layer 9a adjacent to the inner space of the tire is expanded like an air bag to form an outer space in the inner space of the tire 1. To do.

  Air is supplied between the inner liner inner and outer layers 9a and 9b via an air supply air valve (check valve), which will be described later, mounted on the inner liner inner layer 9a. That is, before the tire 1 shown in FIG. 1 is mounted on a rim (not shown), air is filled between the inner liner inner and outer layers 9a and 9b through an air valve. When the inner liner inner and outer layers 9a and 9b are filled with air, the inner liner inner layer 9a expands toward the inside of the tire as described above.

  Here, the pressure of the air to be filled is specified in accordance with industrial standards, standards, etc. that are effective in the area where the tire is manufactured, sold, or used, such as JATMA, TRA, ETRTO, etc., and is specified according to the load capacity. Tire internal pressure). Thereafter, the tire 1 is mounted on the rim, and the internal space of the tire 1 is filled with air until the internal pressure reaches the predetermined pressure, so that the tire internal space is filled with the inner liner inner layer 9a in the radial direction of the tire. An inner space A1 and an outer space A2 that are partitioned inward and outward are formed.

In this way, by setting the inner space A1 and the outer space A2 inside the tire 1 partitioned by the inner liner inner layer 9a to the same predetermined internal pressure, compared to a conventional tire in which the internal pressure of the air bladder is different from that of the conventional tire. Thus, the pressure balance is good, and tire performance that is the same as that of a normal tire during traveling can be obtained.
Further, in this embodiment, since the inner liner 9 has two inner and outer layers and is filled with air between the inner and outer layers 9, there is no need to change the process in the production as will be described later. There is also an advantage that can be applied as it is.

  In addition, as a member that divides the space between the tire inner surface and the rim in the tire, instead of the inner liner, for example, a rubber sheet that supports a load from the inner surface of the tire (here, including the inner liner 9 is a general term) A protective sheet) may be used. In that case, the rubber sheet is produced separately for the inner layer and the outer layer, like the inner liner inner and outer layers 9a and 9b, either by joining both end portions in the width direction, or the inner layer and the outer layer are connected to a tube or It may be formed integrally in a bag shape and joined to the tire inner surface in a conventional molding process.

Next, the manufacture of the tire 1 will be described.
FIG. 3 is a diagram schematically showing the molding of the inner liner 9 in the manufacture of the tire 1 according to the present embodiment.
In manufacturing, it is the same as a normal tire manufacturing method. Here, as an example, the inner liner inner layer 9 a is wound around the molding drum 20, and a release film 10, which is preferably a sheet of a material that crosslinks at a low melting point, such as a polybutadiene resin, is wound thereon, followed by peeling. An inner liner outer layer 9b is formed on the film 10, and a side wall 3, chafer rubber 8, other carcass (layer) 5, bead core 6 and the like are sequentially wound and bonded onto the inner liner outer layer 9b. In the process, the inner liner outer layer 9b is joined to the bead portion to form a cylindrical molded body (not shown). This molded body is expanded in a toroidal shape, and a green tire is molded by crimping an inner periphery of a cylindrical molding formed by bonding a belt, a tread member, or the like to the outer periphery.
The green tire molded as described above is then vulcanized with the release film 10 attached thereto to produce a tire. After the raw tire is vulcanized, a hole 9c (FIG. 4) is opened in the inner liner inner layer 9a, and an air valve 15 (FIG. 4) is mounted as will be described later.

The above is a description of the case where the inner liner 9 has a two-layer structure, and the inner liner inner layer 9a is used as a member that divides the space between the tire inner surface and the rim. A rubber sheet may be used instead.
At that time, as already described, the rubber sheet may be structured to join only the end portions in the width direction of the two rubber sheets, or may be formed in a tube shape in advance.

FIG. 4 is a diagram illustrating a procedure for mounting the air valve 15 to the inner liner inner layer 9a.
When attaching the air valve 15 to the inner liner inner layer 9a, first, a hole 9c is formed in the inner liner inner layer 9a, and a threaded stem 15b of the air valve 15 with the flange 15a is provided in the hole 9c of the inner liner inner layer 9a. The flange 15a is inserted into the inner liner inner layer 9a. Subsequently, the nut 16 is attached to the thread groove of the stem 15b protruding outward from the inner liner inner layer 9a, and the inner liner inner layer 9a is sandwiched between the flange 15a and the nut 16 and tightened. In this way, the air valve 15 is attached to the inner liner inner layer 9a.
Next, air is supplied between the inner liner inner and outer layers 9a and 9b through the mounted air valve 15, and the inner liner inner layer 9a is expanded until the inner pressure becomes the predetermined inner pressure.
The air valve 15 itself can be used not only for tires but also for other pneumatic products such as exercise balls and air mats as air intake and air pressure maintaining means.

  Subsequently, the tire 1 is assembled with a rim, and the inside of the tire 1, that is, the space between the inner liner inner layer 9a and the rim is filled with air until the predetermined internal pressure is reached. As a result, an inner space A1 and an outer space A2 filled with air of a predetermined pressure are formed inside the tire (FIG. 2).

Next, the state at the time of occurrence of puncture of the tire 1 according to the present embodiment will be described.
FIG. 5 is a cross-sectional view of a main part for explaining a state at the time of occurrence of puncture of the tire according to the present embodiment. FIG. 5A is a state in which the internal pressure of the tire 1 is reduced due to puncture, and FIG. It is sectional drawing which each shows the state which closed the puncture hole by the inner liner inner layer 9a.
First, in order to compare with the tire at the time of occurrence of puncture in FIG. 5, referring to the tire cross-sectional view in the normal running state of FIG. 2, the inner liner inner layer 9 a is supplied through the air valve 15 as shown in the figure. The air is maintained at a predetermined internal pressure P1 of the tire 1, and the pressure is balanced inside and outside the inner liner inner layer 9a. Therefore, smooth running is possible like a normal tire.

Next, the state of the tire when the air filled between the inner liner inner and outer layers 9a and 9b is released to the atmosphere, such as when the tread 2 is punctured in this state, will be described.
FIG. 5A is a cross-sectional view showing the state of the tire when puncture occurs.
In this state, a hole is opened in the tread 2, air filled between the inner liner inner and outer layers 9a and 9b leaks from the inner liner outer layer 9b, and the inner pressure approaches the atmospheric pressure. At that time, the air valve 15 blocks the flow of air between the inner space of the tire 1 and the space between the inner liner inner and outer layers 9a and 9b, so that the inner liner inner layer 9a pushes against the air pressure of the tire 1 inside. Then, it moves toward the tread 2 side. Meanwhile, the internal pressure of the tire 1 gradually decreases as the inner liner inner layer 9a expands.

When puncture occurs, the inner liner inner layer 9a continues to expand toward the outer side of the tire in this way, and finally overlaps the inner liner outer layer 9b, sealing the hole opened by the puncture and reducing the internal pressure of the tire 1 Stop it.
FIG. 5B shows that the inner liner inner layer 9a finally contacts and closes the hole opened by the puncture, and the tire internal pressure is reduced from the predetermined internal pressure P1 to P2. That is, the tire can travel to a place where the tire can be replaced in a state of the reduced internal pressure P2.

  DESCRIPTION OF SYMBOLS 1 ... Tire (safety tire), 2 ... Tread, 3 ... Side wall, 4 ... Belt layer, 5 ... Carcass, 6 ... Bead core, 7 ... Bead filler, 8. .. Chafer rubber, 9 ... inner liner, 9a ... inner liner inner layer, 9b ... inner liner outer layer, 10 ... release film, 15 ... air valve, 16 ... nut, A1 ... -Inside space, A2 ... Outside space.

Claims (8)

A safety tire having a protective sheet that divides a space between the tire inner surface and the rim into an inner space and an outer space in a mounting posture in which the tire is mounted on the rim and the tire internal pressure is filled to a predetermined internal pressure,
A safety tire in which a width direction end portion of the protective sheet is integrally joined to an inner surface side of a bead portion of the tire. In the safety tire according to claim 1,
A safety tire having the same internal pressure in the inner space and the outer space. In the safety tire according to claim 1 or 2,
The protective tire is a safety tire that is an inner liner composed of inner and outer layers. In the safety tire according to claim 1 or 2,
The safety tire is a safety tire that is an inflatable rubber sheet composed of inner and outer layers that load-support the tire from the inner surface. A method for manufacturing a safety tire including a protective sheet that divides a space between a tire inner surface and a rim into an inner space and an outer space in a mounting posture in which the tire is mounted on a rim and the tire inner pressure is filled to a predetermined inner pressure. Because
Arranging the outer protective sheet on the inner protective sheet via the release sheet, and joining the widthwise ends of the inner and outer protective sheets; and
Bonding the widthwise both ends of the outer protective sheet to the bead portion of the tire;
Arranging a tire constituent member on the protective sheet and molding a raw tire;
Vulcanizing the green tire;
The manufacturing method of the safety tire which has this. A method for manufacturing a safety tire including a protective sheet that divides a space between a tire inner surface and a rim into an inner space and an outer space in a mounting posture in which the tire is mounted on a rim and the tire inner pressure is filled to a predetermined inner pressure. Because
Joining the widthwise ends of the protective sheet formed in a tube or bag shape by joining the widthwise ends to the bead portion of the tire; and
Arranging a tire constituent member on the protective sheet and molding a raw tire;
Vulcanizing the green tire;
The manufacturing method of the safety tire which has this. In the manufacturing method of the safety tire according to claim 5 or 6,
The method for manufacturing a safety tire, wherein the protective sheet is an inner liner composed of inner and outer layers. In the manufacturing method of the safety tire according to claim 5 or 6,
The said protective sheet is a manufacturing method of the safety tire which is an expandable rubber sheet which consists of an inner and outer layer which carries out load support of the tire from the inner surface.

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