JP2009143132A - Vulcanizing envelope and manufacturing method of regenerated tire - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an envelop applicable irrespective of kinds of tires (sizes, shapes). <P>SOLUTION: The vulcanizing envelope 7 can cover the outside of the molded tire 1 which has been formed by arranging the vulcanized precure tread 5, through the unvulcanized cushion rubber 3, on the crown part of the base tire 2. The vulcanizing envelope 7 is composed of the bands 9 that pass the rim holes of the molded tire 1 and that are wound, along the outside of the molded tire 1, continuously and spirally to the tire width direction so that the side edge parts of the bands may partially be overlapped. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a vulcanized envelope capable of covering the outer surface of a molded tire formed by disposing a vulcanized precured tread through an unvulcanized cushion rubber on a crown portion of a base tire, and molding The present invention relates to a method for manufacturing a retread tire by manufacturing a retread tire by vulcanizing and bonding a precure tread to a base tire by vulcanizing a used tire.

  Pneumatic tires are made by attaching tread rubber that touches the road surface to the base tire, and the base tire often wears with use even after the life of the tread rubber has expired. The tread rubber part is covered with new rubber or recycled tire materials and used again as retreaded tires. Rehabilitation method for manufacturing retreaded tires is roughly classified, and a non-patterned unvulcanized tread rubber is affixed to a base tire, vulcanized in a mold, and a pattern is applied (hot retreading method) There are two types: a pre-curing method (cold retreading method) in which a pre-cured tread with a vulcanized pattern is attached to a base tire without using a mold and vulcanized in a vulcanizing can.

  Here, in manufacturing a retread tire from a used tire according to the cold retreading method, the tread rubber is removed from the surface of the tire to form a base tire, and an unvulcanized cushion rubber layer is installed on the outer surface of the base tire, In addition, a new precure tread is affixed on the cushion rubber layer, and then a rubber tube-like bag body that resembles the tire shape, called a vulcanization envelope, is placed on the tire and then placed in a vulcanization can. The mainstream was to vulcanize with the method (see Patent Document 1). Such a rehabilitation method is said to be particularly advantageous in the case of renewing various, multi-brand, and small amount of tires because a tread rubber is already vulcanized and does not require a mold for vulcanization.

  By the way, there are roughly the following three types of vulcanization envelopes that are generally used at present.

  As shown in FIG. 7A, the first type has an outer envelope 103 disposed on the outer surface portion of the tire 101 and an inner envelope 105 disposed on the inner surface portion of the tire 101. It is a vulcanization envelope which keeps airtightness inside by locking each end part mutually. This is mainly used when a pressure is applied to the inner surface of the tire to maintain the tire shape during vulcanization and there is a repair location on the inner surface that cannot be directly applied.

  In the second type, as shown in FIG. 7B, an envelope 107 is disposed on the outer surface portion of the tire 101, and each end portion is interposed between the bead seal ring 109 and each bead portion 101 a of the tire 101. It is a vulcanization envelope that holds the inside airtight by being sandwiched (see Patent Document 2). This is used when there is no repair location on the inner surface of the tire and pressure can be directly applied to the inner surface of the tire mainly for maintaining the tire shape during vulcanization.

In the third type, as shown in FIG. 7 (c), an envelope 111 is disposed on the outer surface of the tire 101, and an inflatable tube 113 is disposed inside the tire 101, and each end of the envelope 111 is disposed. This is a vulcanized envelope that keeps the inside of the envelope 111 airtight by sandwiching the portion between the rim 115 and each bead portion 101 a of the tire 101. Similar to the first type of vulcanization envelope, this is used when there is a repair point on the inner surface of the tire and pressure cannot be directly applied thereto.
JP 2006-281683 A JP-A-5-154940

  However, in any of these types, it is necessary to use a vulcanization envelope suitable for the size of the tire. On the other hand, as described above, the cold rehabilitation system handles various types, large brands, and small amounts of tires. Therefore, it becomes necessary to prepare a large number of vulcanization envelopes according to the type (size and shape) of the tire. As a result, the manufacturing cost of the retreaded tire increases, and there is a problem that an extra space for storing the vulcanized envelope must be secured.

  Accordingly, an object of the present invention is to solve these problems, and an object of the present invention is to provide a vulcanized envelope applicable regardless of the type (size, shape) of the tire.

  In order to achieve the above object, the vulcanized envelope of the present invention is an outer surface of a molded tire formed by disposing a vulcanized precure tread through an unvulcanized cushion rubber at the crown portion of a base tire. In the tire width direction, the vulcanization envelope passes through the rim hole of the molded tire and extends partially along the outer surface of the molded tire. It is characterized by comprising a band continuously wound in a spiral. By adopting such a configuration, it becomes possible to form a vulcanization envelope using the same band for any tire regardless of the type (size, shape) of the tire.

  The band is preferably made of rubber or resin.

  Furthermore, the band preferably has a width larger than the groove width of the widthwise groove of the precure tread.

  Furthermore, it is preferable that the width | variety edge part of the band which overlaps has an engaging part which mutually engages, respectively.

  And it is preferable that a vulcanization envelope has an air supply / exhaust hole which penetrates the front and back of this vulcanization envelope.

  In order to achieve the above object, the method for producing a retread tire according to the present invention has been molded by disposing a vulcanized pre-cured red rubber through an unvulcanized cushion rubber on the crown portion of the base tire. Prior to the vulcanization treatment, a band is passed through the rim hole of the molded tire before vulcanizing the precured tread to the base tire by vulcanizing the molded tire after forming the tire. Along with the outer surface of the molded tire, a vulcanized envelope is formed by winding while continuously applying a predetermined tension spirally in the tire width direction so that the width edges of the band partially overlap. It is characterized by doing. By adopting such a configuration, it becomes possible to form a vulcanization envelope using the same band for any tire regardless of the type (size, shape) of the tire.

  It is preferable that the vulcanization envelope is provided with air supply / exhaust holes that penetrate the front and back of the vulcanization envelope.

  Furthermore, it is preferable that a bead seal ring is attached to both bead portions of the molded tire via the vulcanized envelope after the band is wound around the molded tire to form a vulcanized envelope.

  Furthermore, after mounting the bead seal ring on both bead portions of the molded tire via the vulcanization envelope, the air remaining between the inner surface of the vulcanization envelope and the outer surface of the molded tire is passed through the air supply / exhaust holes. It is preferable to suck.

  Moreover, it is preferable to supply air between the inner surface of the vulcanization envelope and the outer surface of the molded tire through the air supply and exhaust holes during the vulcanization process.

  According to the vulcanized envelope and the method for producing a retread tire of the present invention, it is possible to provide a vulcanized envelope that can be applied regardless of the type (size, shape) of the tire.

  1A and 1B are diagrams schematically showing a vulcanized envelope according to an embodiment of the present invention applied to a molded tire, in which FIG. 1A is an overall view, and FIG. 1B is a partial cross section along the tire circumferential direction. FIG. Here, the molded tire 1 (see FIG. 1B) is an unvulcanized cushion on the crown portion of the base tire 2 formed by subjecting a used pneumatic tire (not shown) to a predetermined buffing process or the like. The rubber 3 is disposed, and the vulcanized precure tread 5 is disposed thereon.

  As shown in FIGS. 1 (a) and 1 (b), the vulcanization envelope 7 of this embodiment is composed of a band-like band 9 having a predetermined width. The band 9 passes through the rim hole of the molded tire 1 and continuously spirally winds along the outer surface of the molded tire 1 in the tire width direction (here, the direction inclined with respect to the tire circumferential direction). Has been. Furthermore, the width edge (edge in the width direction) E of the band 9 partially overlaps. The band 9 preferably has a melting point of 150 ° C. or higher so that it can withstand the temperature during vulcanization. Further, the thickness of the band 9 is preferably 5 mm or more so that the airtightness in the vulcanization envelope 7 can be reliably maintained by ensuring a predetermined rigidity. Moreover, the band 9 preferably has a predetermined shrinkage force so that the precure tread 5 can be pressed against the base tire 2 when wound around the molded tire 1, and is preferably made of rubber, for example. In addition to the rubber, a resin band made of nylon or polypropylene can be applied to the band 9.

  According to the vulcanization envelope 7 of this embodiment, since the vulcanization envelope 7 is formed by winding the band 9 around the molded tire 1, any tire regardless of the type (size, shape) of the tire. In contrast, the vulcanization envelope 7 can be formed using the same band 9.

  Next, another band 9 applicable to the vulcanization envelope 7 of the present invention will be described. FIG. 2 is a partial cross-sectional view along the tire circumferential direction schematically showing the vulcanized envelope 7 of the other embodiment of the present invention together with the molded tire 1, and FIG. 3 is still another embodiment of the present invention. FIG. 4 is a partial cross-sectional view schematically showing the vulcanized envelope 7 of the embodiment together with the molded tire 1 along the tire circumferential direction, and FIG. 4 shows the vulcanized envelope 7 of still another embodiment of the present invention. It is a schematic diagram shown in the state applied to.

In the vulcanization envelope 7 of the embodiment shown in FIG. 2, the band 9 constituting the vulcanization envelope 7 has a groove width W _{g of} a groove in the width direction of the precure tread 5 (a groove extending obliquely with respect to the tire circumferential direction). having a larger width _{W b} than. Other configurations and operations are the same as those of the vulcanization envelope 7 (see FIG. 1) of the previous embodiment.

  According to the vulcanization envelope 7 of this embodiment, the vulcanization envelope 7 can be formed using the same band 9 for any tire regardless of the type (size, shape) of the tire. Further, since there is no fear that the width edge E of the band 9 falls into the groove in the width direction of the precure tread 5, the airtightness in the vulcanization envelope 7 can be reliably maintained.

  In the vulcanization envelope 7 of the embodiment shown in FIG. 3, the width edge E of the overlapping band 9 has an engaging portion 9 a that engages with each other. Other configurations and operations are the same as those of the vulcanization envelope 7 (see FIG. 1) of the previous embodiment.

  According to the vulcanization envelope 7 of this embodiment, the vulcanization envelope 7 can be formed using the same band 9 for any tire regardless of the type (size, shape) of the tire. Further, since the engaging portions 9a of the overlapping bands 9 are engaged with each other, the shape of the vulcanization envelope 7 is stabilized and the airtightness in the vulcanization envelope 7 is more reliably maintained.

  In the vulcanization envelope 7 of the embodiment shown in FIG. 4, the vulcanization envelope 7 has a valve 13 as an air supply / exhaust hole penetrating the front and back. The valve 13 can be connected to a pump (not shown) that can supply and exhaust air in the vulcanization envelope 7. Thereby, the inside of the vulcanization envelope 7 can be set to a desired pressure, and the pressing force when pressing the precure tread 5 against the base tire 2 can be set as desired.

  Next, a method for manufacturing a retread tire according to the present invention will be described. Here, Fig.5 (a)-(d) is the schematic diagram which showed the procedure which manufactures a retreaded tire according to this invention. In order to manufacture a retread tire according to the present invention, prior to performing the heat treatment (vulcanization) with the vulcanizing can 11, first, a band-like band having a predetermined width and thickness as shown in FIG. 9 is passed through the rim hole 1a of the molded tire 1, and the width edge (edge in the width direction) E of the band 9 partially overlaps along the outer surface of the molded tire 1. The vulcanization envelope 7 is formed as shown in FIG. 5B by continuously winding in a spiral manner in the width direction (here, the direction inclined with respect to the tire circumferential direction) while applying a predetermined tension. Thereby, the precure tread 5 is pressed against the base tire 2, and the state is maintained. Further, in this state, as shown in FIG. 5 (c), the vulcanization envelope 7 can be provided with a valve 13 as an air supply / exhaust hole penetrating the front and back of the vulcanization envelope 7. Each bead seal ring 15 can be fitted and attached via the vulcanization envelope 7. Next, as shown in FIG. 5 (d), the molded tire 1 is put into the vulcanizing can 11 together with the vulcanization envelope 7, and the inside of the vulcanization envelope 7 (the outer surface of the molded tire 1 and the inner surface of the vulcanization envelope 7). The air remaining in the space between the two is sucked through the valve 13 by, for example, a vacuum pump (not shown). At this time, since the inside of the vulcanization envelope 7 is sealed by the bead seal ring 15, only the air in the vulcanization envelope 7 can be sucked. Thereafter, the molded tire 1 is heated under desired conditions. After such heat treatment, the band 9 is reversely wound and the product tire is taken out. Band 9 is reusable.

  According to the method for manufacturing a retread tire according to the present invention, the vulcanized envelope 7 is formed by winding the band 9 around the molded tire 1, so that any tire is available regardless of the type (size, shape) of the tire. In contrast, the vulcanization envelope 7 can be formed using the same band 9.

  Furthermore, by using the method for manufacturing a retread tire according to the present invention, the band 9 is passed through the rim hole 1a of the molded tire 1 and the width edge E of the band 9 is extended along the outer surface of the molded tire 1. It is possible to automate the winding operation while applying a predetermined tension spirally in the tire width direction (direction inclined with respect to the tire circumferential direction) so that the tires partially overlap each other. Such an operation can be performed using, for example, an automatic packing means (a banding packing machine) (not shown). Conventionally, mounting of an annular vulcanization envelope similar to the tire shape as shown in FIGS. 7A to 7C to the tire has been difficult due to its shape, and all has been done manually. . In this case, the time required to attach the vulcanized envelope to the tire is about 4 minutes, and since all was done manually, there was a problem that wearing deviation occurred and the productivity was inferior. On the other hand, according to the manufacturing method of the constituent tire of the present invention, the attachment of the vulcanization envelope 7 to the tire is a simple operation of winding the band 9 around the molded tire 1, so that it can be applied to automation. Easy. When the band 9 is automatically wound around the molded tire 1 to form the vulcanization envelope 7, the man-hour required for mounting the vulcanization envelope 7 can be reduced by about 70%.

  Further, after the band 9 is wound around the molded tire 1 and the vulcanized envelope 7 is formed, the bead seal rings 15 are respectively attached to both bead portions 1b of the molded tire 1 via the vulcanized envelope 7. The inside of the vulcanization envelope 7 is more reliably sealed, and deformation of the molded tire 1 during vulcanization is prevented.

  Further, after the bead seal ring 15 is attached to both bead portions 1b of the molded tire 1 via the vulcanization envelope 7, if the air remaining in the vulcanization envelope 7 is sucked via the valve 13, the precure The tread 5 can be more reliably pressed against the base tire 2. The bead seal ring may be attached to both bead portions of the molded tire 1 before or after the valve 13 is attached to the vulcanization envelope 7 or simultaneously with the attachment of the valve 13.

  Furthermore, it is preferable to supply air into the vulcanization envelope 7 sealed by the bead seal ring 15 via the valve 13 during the heat treatment in the vulcanization can 11. That is, as shown in FIG. 6, at time t0 before the start of the heat treatment, the air in the vulcanization envelope 7 is exhausted through the valve 13 (the inside of the vulcanization envelope 7 is set to a negative pressure (−Pa)). Then, at the time t1 when the heat treatment is started and the temperature and pressure in the vulcanizing can rise to reach a predetermined environment, air is supplied into the vulcanizing envelope 7 through the valve 13 (inside the vulcanizing envelope 7). A positive pressure (+ Pa) is preferable. According to this, pressure is applied to the groove bottom of the precure tread 5, adhesion to the base tire is improved, and an air layer is formed in the groove part of the precure tread 5 to stabilize the cross-sectional shape of the groove part. As a result, it is possible to prevent the end of the precure tread 5 from being lifted from the base tire 2 due to the deformation of the cross-sectional shape of the groove.

  As is clear from the above description, the present invention has made it possible to provide a vulcanized envelope that can be applied regardless of the type (size, shape) of the tire.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure typically shown in the state which applied the vulcanization envelope of embodiment according to this invention to the shape | molded tire, (a) is a general view, (b) is a fragmentary sectional view in alignment with a tire circumferential direction. It is a fragmentary sectional view in alignment with the tire peripheral direction which shows typically a vulcanization envelope of other embodiments of this invention with a molded tire. It is a fragmentary sectional view in alignment with the tire peripheral direction which shows typically a vulcanization envelope of other embodiments of this invention with a molded tire. It is a schematic diagram shown in the state which applied the vulcanization envelope of further another embodiment of this invention to the shape | molded tire. (A)-(d) is the schematic diagram which showed the procedure which manufactures a retreaded tire according to this invention. It is the graph which showed temporally the relationship between the pressure inside a vulcanization can and the pressure inside a vulcanization envelope at the time of heat-processing a molded tire according to this invention. It is a fragmentary sectional view which follows the tire width direction which shows the conventional vulcanization envelope with a molded tire.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Molded tire 2 tires 3 Cushion rubber 5 Precured tread 7 Vulcanization envelope 9 Band 11 Vulcanization can 13 Valve 15 Bead seal ring

Claims (10)

In the vulcanized envelope capable of covering the outer surface of a molded tire formed by disposing a vulcanized precure tread through an unvulcanized cushion rubber on the crown portion of the base tire,
The vulcanized envelope is continuously spirally wound in the tire width direction so as to partially overlap the width edge along the outer surface of the molded tire while passing through the rim hole of the molded tire. Vulcanized envelope, characterized in that it is composed of an open band.   The vulcanization envelope according to claim 1, wherein the band is made of rubber or resin.   The vulcanization envelope according to claim 1 or 2, wherein the band has a width larger than a groove width of a width direction groove of the precure tread.   The vulcanization envelope according to any one of claims 1 to 3, wherein the overlapping width edges of the bands respectively have engaging portions that engage with each other.   The said vulcanization envelope is a vulcanization envelope as described in any one of Claims 1-4 which has an air supply / exhaust hole which penetrates the front and back of this vulcanization envelope. A vulcanized precured red rubber is disposed on the crown portion of the base tire via an unvulcanized cushion rubber to form a molded tire, and then the molded tire is subjected to a vulcanization treatment to perform the vulcanization treatment. In vulcanizing and bonding Cure Red to the base tire,
Prior to the vulcanization treatment, the band is passed through the rim hole of the molded tire and continuously in the tire width direction so that the width edge of the band partially overlaps along the outer surface of the molded tire. A method for producing a retread tire, which comprises forming a vulcanization envelope by winding a predetermined tension in a spiral manner.   The method for manufacturing a retread tire according to claim 6, wherein the vulcanization envelope is provided with an air supply / exhaust hole penetrating the front and back of the vulcanization envelope.   The bead seal ring is attached to both bead portions of the molded tire via the vulcanized envelope after the band is wound around the molded tire to form the vulcanized envelope, respectively. Manufacturing method for retreaded tires.   After the bead seal ring is mounted on both bead portions of the molded tire via the vulcanization envelope, the air remaining between the inner surface of the vulcanization envelope and the outer surface of the molded tire is supplied to the bead seal ring. The method for producing a retread tire according to claim 8, wherein suction is performed through the exhaust hole.   The method for producing a retread tire according to claim 9, wherein air is supplied between an inner surface of the vulcanization envelope and an outer surface of the molded tire through the air supply / exhaust hole during the vulcanization process.

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