JP2009166294A - Manufacturing method of air pouch for safety tire - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of an air pouch for a safety tire, which can prevent the resin film to prevent the sticking of the unvulcanized pressure-retaining member from upsetting the internal pressure piping system by its melting upon vulcanization. <P>SOLUTION: In the process of forming, before vulcanizing the air pouch for the safety tire, the unvulcanized tubular pressure-retaining part, which consists of arranging the unvulcanized pressure-retaining member 1A for the pressure-retaining part on the molding drum 101, pasting the resin film member 6A to prevent the mutual sticking of the pressure-retaining member 1A on the outside of the pressure-retaining member 1A and then folding back both sides of the width direction of this pressure-retaining member 1A and subsequently bonding both ends of the width direction of the pressure-retaining member 1A over the whole circumference, as the resin film member 6A for the sticking prevention the one at least part of which is crosslinked is pasted in advance. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention is housed in a tire, and when the tire internal pressure is normal, a space is formed at least between the inner surface of the tire, and the diameter is changed with a decrease in the tire internal pressure to support the load from the tire. In particular, the present invention relates to a method for manufacturing a safety tire air bag having a rubber tubular pressure holding portion filled with a predetermined internal pressure. The present invention relates to one that does not clog a piping system that melts in a process and supplies and exhausts internal pressure to a pressure holding member.

  Reinforcing members such as a reinforcing tube, reinforcing rubber, and reinforcing belt, or a foam, elastic body, medium, etc. as a safety tire that can travel a certain distance even in a run-flat state in which the tire internal pressure has suddenly decreased due to puncture etc. In recent years, tires containing a child or the like have been known, and in recent years, from the viewpoint of suppressing manufacturing cost and weight increase, the tires are housed inside a safety tire and in a run-flat state where the internal pressure of the tire is reduced, The spread of an air bag for a safety tire having a rubber tubular pressure holding portion filled with a predetermined internal pressure so as to expand and deform as the internal pressure decreases and to replace the load support from the tire (for example, Patent Document 1). reference).

  As a method for producing such an air sac, the following steps are known (for example, see Patent Document 1). First, as a molding process, an unvulcanized annular sheet unvulcanized pressure retaining member for a pressure retaining part is disposed on the periphery of a molding drum for molding an unvulcanized safety tire air bag. After adhering a resin film for preventing adhesion between the unvulcanized pressure retaining members to the outside, the both ends of the unvulcanized pressure retaining member are folded back and joined to the entire circumference. Then, an unvulcanized tubular pressure holding member is formed, and then another unvulcanized member is attached to the outside of the tubular pressure holding member to form an unvulcanized safety tire air bag.

After that, the unvulcanized safety tire air sac is heated and vulcanized in a state of being accommodated in the vulcanization mold to form a safety tire air sac as a product. In the above process, the unvulcanized safety tire air sac is stored in a predetermined storage location until called in time for the cycle time of the vulcanizer, and the resin film is in a tube shape. It is affixed so as to prevent adhesion between the inner surfaces of the unvulcanized pressure holding member.
International Publication No. 06/135012 Pamphlet (2006)

  However, such a resin film has conventionally had an internal pressure supplied to the inside of a pressure holding member that forms a tube shape by melting the film due to high temperature in the process of vulcanizing an air bag for an unvulcanized safety tire. There was a problem of clogging the piping system.

  The present invention has been made in view of such a problem, and prevents a resin film for preventing adhesion of an unvulcanized pressure holding member from being melted during vulcanization and hindering an internal pressure piping system. An object of the present invention is to provide a method for manufacturing a safety tire air bag.

<1> is housed in the tire, and when the tire internal pressure is normal, a space is formed at least between the inner surface of the tire, and the diameter is expanded as the tire internal pressure decreases, so that the load is supported from the tire. In the method of manufacturing an air bag for a safety tire having a rubber tubular pressure holding portion filled with a predetermined internal pressure,
Prior to vulcanization of the air sac for a safety tire, an unvulcanized pressure holding member for the pressure holding portion is disposed on the molding drum, and then the pressure holding members are prevented from sticking to each other outside the pressure holding member. The resin film member to be bonded is attached, and then both sides in the width direction of the pressure holding member are folded, and then both ends in the width direction of the pressure holding member are joined over the entire circumference to form an unvulcanized tubular pressure holding portion. In the process, a method for producing an air sac for a safety tire is characterized in that at least a part of the resin film member for adhesion prevention is pasted in advance.

  <2> is a method for producing an air sac for a safety tire, wherein the resin film member according to <1> has a gelation rate of 50 to 100%.

  Here, the gelation rate refers to the ratio of the remaining mass that cannot be dissolved when THF (tetrahydrofuran), which is a good solvent, is dissolved, and is used as a specification that represents the degree of crosslinking. The higher the gelation rate, the higher the degree of crosslinking.

  <3> is a method for producing an air bag for a safety tire, wherein, in <1> or <2>, the resin film member is crosslinked by irradiating an electron beam.

  <4> is one or more of thermoplastic polyurethane resin, polyethylene resin, polypropylene resin, polybutadiene resin, and polyvinylidene chloride resin as the resin film member in any one of <1> to <3> This is a method for producing an air sac for a safety tire characterized by using the above resin.

  <1> According to <1>, since the resin film member for adhesion prevention is pasted at least partially cross-linked, it can be prevented from being melted by a high temperature during vulcanization, and is used for supplying internal pressure during vulcanization. The piping system will not be clogged.

  According to <2>, since the resin film member having a gelation ratio of 50 to 100% is used, melting during vulcanization can be more effectively suppressed.

  According to <3>, since the resin film member is crosslinked by irradiating an electron beam, the crosslinking can be performed with a simple apparatus.

  According to <4>, as the resin film member, one or more of a thermoplastic polyurethane resin, a polyethylene resin, a polypropylene resin, a polybutadiene resin, and a polyvinylidene chloride resin is used. Can be advantageous.

  Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view showing a safety tire air sac targeted by the manufacturing method of the present invention. The safety tire air sac 10 has a predetermined internal pressure in an annular space 12 surrounded by a tire 21 and a rim 22. The pressure holding part 1 that is mounted in a state of filling and holding the shape against the internal pressure P2 of the hollow part 11, and the diameter expansion suppression that suppresses the radial expansion of the air sac 10 in addition to the holding of the internal pressure P2 The pressure holding unit 2 includes a fiber layer 19 in which, for example, a PET non-woven fabric is coated with rubber, and a rubber reinforcing layer 18 disposed on the outside thereof.

  An inner liner layer 5 made of air-permeable rubber for preventing the permeation of pressurized air filled in the hollow portion 11 to the outside, and an unvulcanized pressure in the manufacturing process are disposed inside the pressure holding portion 1. A resin film 6 for preventing the holding portions 1 from sticking to each other is attached.

  The air sac 10 is provided with a valve 9 for filling the hollow portion 11 with air and a spud 8 for attaching the valve 9. In the figure, 3 represents a reinforcing layer, and 4a and 4b represent surface layers.

2-9 is sectional drawing which illustrates the state which assembles each member which comprises the air sac 10 on a shaping | molding drum, In order to shape the air sac 10, first, as shown in FIG. A pressure holding member 1 </ b> A corresponding to the pressure holding unit 1 is disposed on the molding drum 101 and the bladder 102. The pressure holding member 1A may be transferred in the form of a ring formed in advance by another molding drum or the like, or a sheet-like member is wound around the molding drum 101 and both ends in the drum circumferential direction are joined to each other to form a ring. Also good.
The pressure holding member 1A is configured by disposing a fiber layer member 19A in which a nonwoven fabric is coated with rubber on the outside of the rubber reinforcing layer member 18A, and the fiber layer member 19A is wider than the rubber reinforcing layer member 18A. Is formed.

  Thereafter, as shown in FIG. 3, an inner liner member 5A made of air-impermeable rubber is wound around the outer side of the pressure holding member 1A, and both circumferential ends thereof are temporarily joined to each other. 6A is wound and the circumferential direction both ends are temporarily joined mutually. However, when the resin film member 6A is wound, the circumferential position of the temporary joint portion of the resin film member 6A is made to substantially coincide with the temporary joint portion of the inner liner member 5A.

  Next, as shown in FIG. 4A, a through-hole 13 that penetrates all of the laminated pressure holding member 1A, inner liner member 5A, and resin film member 6A in the thickness direction is formed. At this time, the through hole 13 is formed at a circumferential position corresponding to the temporary joining portion of the inner liner member 5A and the resin film member 6A for a process to be described later. FIG. 4B is a view of the vicinity of the through hole 13 of the pressure holding member 1A as viewed from the inside in the radial direction.

  Subsequently, as shown in a cross-sectional view orthogonal to the molding drum axis in FIG. 5, the temporary joining portion of the inner liner member 5 </ b> A and the resin film member 6 </ b> A is peeled to expose the peripheral portion of the through hole 13 of the pressure holding member 1 </ b> A. 8 is attached to the peripheral portion of the through hole 13 on the outer side (inner liner member 5A) of the pressure holding member 1A, and then, as shown in FIG. 6, the temporary joint between the inner liner member 5A and the resin film member 6A is peeled off. The part thus obtained is put back and pasted on the spud 8, and then finally joined to the circumferential ends of these members 5 </ b> A and 6 </ b> A.

  In addition, the temporary joining part of the inner liner member 5A and the resin film member 6A can be easily peeled off, and this is why the through hole 13 was formed in the vicinity of the temporary joining part in the previous step.

  7 (a) and 7 (b), the spud 8 is provided so as to penetrate the spud body 8a made of a truncated cone rubber and the center of the spud body 8a, as shown in the plan view and the sectional view, respectively. A female screw portion 8c for screwing the valve is formed on the inner surface of the screw member 8b. When the spud 8 is attached to the pressure holding member 1A, The member 8b is pasted so as to be inserted into the through hole 13.

  Here, when affixing the resin film member 6A, it is not necessary to adhere this to the inner inner liner member 5A, and if both ends in the circumferential direction are overlapped and the ends are heat-welded with a trowel, etc. Good.

  Next, as described in the prior art, the bladder 102 is operated to turn back both sides in the width direction of the pressure holding member 1A, the inner liner member 5A, and the resin film member 6A. As shown in FIG. About member 1A and inner liner member 5A, those width direction both ends are joined mutually by the adhesive force which these members 5A and 6A have.

  As the next step, one or more reinforcing layers are wound, and as shown in FIG. 9, a diameter expansion suppressing member 2A to be the diameter expansion suppressing portion 2 is attached, and the molding of the air sac member is completed. Vulcanization forms the air sac 10.

  Here, the manufacturing method of the air bag for a safety tire according to the present invention is characterized in that a resin that has been cross-linked in advance is used for the resin film member 6A, and this partially melts during vulcanization. As a result, it is possible to prevent clogging of the piping system caused by this factor.

  In addition, it is preferable to use a gelling rate of the front resin film member 6A of 50 to 100%. Furthermore, the resin film 6A is efficiently cross-linked by irradiation with an electron beam. As a material for the resin film member 6A, one or more of a thermoplastic polyurethane resin, a polyethylene resin, a polypropylene resin, a polybutadiene resin, a screen, and a polyvinylidene chloride resin can be preferably exemplified.

An air bag for a safety tire formed by pasting an uncrosslinked resin film with a gelation rate of 0% on the outside of the inner liner member 5A is a conventional example, and the resin film is partially crosslinked by electron beam irradiation and gelled. Taking those having a conversion rate of 50% as examples, after vulcanization, the safety tire air sac was taken out from the mold, cut, and visually checked for the degree of melting of the resin film. The results are shown in Table 1.
The conditions and the like used to prototype the safety tire air sac are as follows.
1) Material: Polybutadiene resin film (manufactured by JSR Corporation)
2) Supported safety tire size: 495 / 45R22.5
3) Total amount of electron beam irradiation: 25kGy

1 is a cross-sectional view showing a safety tire pneumatic bladder according to an embodiment of the present invention in a state in which a predetermined internal pressure is filled in an annular space surrounded by a tire and a rim. It is width direction sectional drawing of the air bladder in the process of shape | molding the air bladder for safety tires. FIG. 3 is a sectional view in the width direction and an arrow view of the air bladder in the process following FIG. 2. FIG. 4 is a cross-sectional view in the width direction of the air bladder in the process following FIG. 3. It is sectional drawing of the direction orthogonal to the axis | shaft of the air bladder in the process following FIG. FIG. 6 is a sectional view in the width direction of the air bladder in the process following FIG. 5. It is the top view and sectional drawing which show a spud. FIG. 8 is a width direction cross-sectional view of the air bladder in the process following FIG. 7. FIG. 9 is a cross-sectional view in the width direction of the air bladder in the process following FIG. 8.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Pressure holding part 1A Pressure holding member 2 Diameter expansion suppression part 2A Diameter expansion suppression member 3 Reinforcement layer 4a, 4b Surface layer 5 Inner liner layer 5A Inner liner member 6 Resin film layer 6A Resin film member 8 Spud 8a Spud body 8b Spud screw member 8c Female thread portion 8d Bottom surface of spud body 9 Valve 10 Air bag for safety tire 11 Hollow portion 13 Through hole 14 Through hole 18 Rubber reinforcement layer 18A Rubber reinforcement layer member 19 Fiber layer 19A Fiber layer member 21 Tire 22 Rim

Claims (4)

When the tire internal pressure is normal and the tire internal pressure is normal, a space is formed at least between the inner surface of the tire and the internal pressure is changed so that the diameter changes as the tire internal pressure decreases to support the load from the tire. In a method of manufacturing an air bag for a safety tire having a rubber tubular pressure holding portion filled with
Prior to vulcanization of the air sac for a safety tire, an unvulcanized pressure holding member for the pressure holding portion is disposed on the molding drum, and then the pressure holding members are prevented from sticking to each other outside the pressure holding member. The resin film member to be bonded is attached, and then both sides in the width direction of the pressure holding member are folded, and then both ends in the width direction of the pressure holding member are joined over the entire circumference to form an unvulcanized tubular pressure holding portion. In the process, a method for producing an air sac for a safety tire, wherein at least a part of the resin film member for preventing adhesion is previously crosslinked.   The method for producing an air sac for a safety tire according to claim 1, wherein the resin film member has a gelation rate of 50 to 100%.   The method for producing an air bag for a safety tire according to claim 1 or 2, wherein, when the resin film member is crosslinked, the resin film member is crosslinked by irradiation with an electron beam.   The resin film member is one or more of thermoplastic polyurethane resin, polyethylene resin, polypropylene resin, polybutadiene resin, and polyvinylidene chloride resin. The manufacturing method of the air bag for safety tires as described in any one of Claims 1-3.

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