JP2009143099A - Vulcanization envelope - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vulcanization envelope that can reduce working man-hours in putting the vulcanization envelope on a base tire with a tread. <P>SOLUTION: The annular vulcanization envelope 9 having an inner diameter larger than the outer diameter of the base tire 1 with the tread formed by disposing a vulcanized precured tread 7 at a crown part 3a of a base tire 3 through an unvulcanized cushion rubber 5, can cover at least the whole outer surface of the precured tread 7. The vulcanization envelope 9 is mounted to the outer surface of the base tire 1 with the tread, and air in a space S1 partitioned by the vulcanization envelope 9 and the base tire 1 with the tread is sucked through an exhaust hole 11 disposed in the vulcanization envelope 9. In the reduced state of pressure in the space S1, the diameter is reduced to press the precured tread 7 to the base tire 3. A sheet-like fiber body 15 surrounding the exhaust hole 11 is provided on the inner surface of the vulcanization envelope 9. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a vulcanization envelope used when a retreaded tire is manufactured by applying a vulcanized precured tread to a base 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.

  Conventionally, the manufacture of retreaded tires by the precure method has been generally performed as follows as described in Patent Document 1. First, a base tire that has undergone predetermined buffing or the like is mounted on a rim, uncured cushion rubber is affixed to a predetermined position of the crown, and vulcanized precure tread is affixed to the outer peripheral surface thereof. Next, a tube is disposed inside the base tire with a tread, and an annular vulcanization envelope is placed over the precure tread, and its end is sandwiched between the bead portion and the rim. Next, by filling the tube with air, the end portion of the vulcanization envelope is fixed between the bead portion and the rim, and air between the vulcanization envelope and the tread-equipped tire is discharged from the exhaust hole of the vulcanization envelope. Suction is applied to create a negative pressure between the vulcanization envelope and the tread base tire. In this state, the base tire and the precure tread are held between the tube and the vulcanization envelope by placing the base tire with the tread in the vulcanization can and filling the inside of the vulcanization can with steam or the like. Then, it is pressurized and heated to vulcanize the cushion rubber. When the precure tread is brought into close contact with the base tire, an outer envelope is disposed on the outer surface of the tire and an inner envelope is disposed on the inner surface of the tire, instead of the vulcanized envelope (rim type). You may apply the vulcanization envelope according to the double envelope system which latches each both ends of an envelope and an inner envelope, respectively.

  By the way, when the air in the space defined by the vulcanization envelope and the tread-equipped tire is sucked from the exhaust hole of the vulcanization envelope, the area in the vicinity of the exhaust hole closely contacts the outer surface of the corresponding tread-equipped tire. However, there is a problem that air in the space cannot be sucked smoothly.

Therefore, in order to solve such a problem, conventionally, for example, an air vent sheet as described in Patent Document 2 has been installed between the vulcanization envelope and the tread-equipped tire in the region immediately below and near the exhaust hole. .
JP-A-7-246665 Japanese Utility Model Publication No. 3-81387

  However, the installation of the air vent sheet has a problem in that the work man-hours increase because the air vent sheet is fixed to the outer peripheral surface of the tread tire with a stapler after forming the tire with the tread. . Furthermore, after vulcanization, a process of removing the driven needle from the tire also occurs. In addition, when covering a tire with a tread fitted with an air vent sheet with a vulcanization envelope, the air vent sheet must be positioned directly under the exhaust hole provided in the vulcanization envelope and in the vicinity thereof. In some cases, it was necessary to remove the vulcanization envelope and cover it again when the sheet was misaligned during testing. Furthermore, there is a problem that the needle marks when the air bleeding sheet is fixed remain on the tire surface, so that the appearance is poor.

  Accordingly, an object of the present invention is to solve these problems, and an object of the present invention is to provide a vulcanization envelope capable of reducing the number of work steps when the vulcanization envelope is put on a tread-equipped tire. There is.

  In order to achieve the above-mentioned object, the present invention is larger than the outer diameter of a tread-equipped pedestal tire in which a vulcanized precured tread is disposed on a crown portion of a pedestal tire via an unvulcanized cushion rubber. An annular vulcanization envelope having an inner diameter and capable of covering at least all of the outer surface of the precure tread. The vulcanization envelope is attached to the outer surface of the tread-equipped base tire and is drilled in the vulcanization envelope. In the state where the air in the space defined by the vulcanized envelope and the tread-equipped tire is sucked through the exhaust hole and the pressure in the space is reduced, the diameter of the precure tread is reduced by reducing the diameter. In the vulcanization envelope that is pressed against the inner surface of the vulcanization envelope, the vulcanization envelope is integrally provided with a sheet-like fiber body that surrounds the exhaust hole on the inner surface thereof. . By adopting such a configuration, it is not necessary to provide an air vent sheet on the outer peripheral surface of the tread-equipped tire, so that the number of work steps can be reduced. Furthermore, since the fibrous body is integrated with the vulcanization envelope, there is no need to remove the needle. Further, since the fibrous body is integrally provided so as to surround the exhaust hole of the vulcanization envelope, the positional displacement of the air vent sheet as in the conventional case does not occur. Furthermore, since the fibrous body is integrated with the vulcanization envelope, needle marks do not remain on the tire surface.

  Furthermore, it is preferable that the fiber body extends at least to a position corresponding to the width direction end of the precure tread.

  Furthermore, the fibrous body is preferably a nonwoven fabric.

  According to the present invention, the sheet-like fiber body surrounding the exhaust hole is integrally provided on the inner surface of the vulcanization envelope, thereby reducing the work man-hour when the vulcanization envelope is put on the base tire with the tread. it can.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view in the width direction when a typical vulcanized envelope according to the present invention is mounted on a tread-equipped tire, before sucking air in a space defined by the vulcanized envelope and the tread-equipped tire. 2 is a developed view showing a part of the inner peripheral surface of the vulcanization envelope shown in FIG. 1, and FIG. 3 is a typical vulcanization according to the present invention. It is sectional drawing which showed the width direction cross section when attaching an envelope to the base tire with a tread in the state after attracting | sucking the air in the space defined by the vulcanization envelope and the base tire with a tread.

  The tread-equipped base tire 1 shown in FIG. 1 has an unvulcanized cushion rubber 5 attached to a predetermined position of a crown portion 3a of a base tire 3 formed by subjecting a used pneumatic tire to a predetermined buffing process, A vulcanized precure tread 7 is attached to the outer peripheral surface.

  The vulcanization envelope 9 is an annular body having an inner diameter larger than the outer diameter of the tread base tire 1. The vulcanization envelope 9 has an exhaust hole 11 penetrating the vulcanization envelope 9, and an air suction valve connected to a vacuum pump (not shown) at the periphery of the exhaust hole 11. 13 is attached. As shown in FIG. 1, the vulcanization envelope 9 forms a space S1 between the vulcanized envelope 9 and the tread-equipped tire 1 when it is mounted on the tread-equipped tire 1. On the other hand, as shown in FIG. Air in the space S1 is sucked through the suction valve 13, and in a reduced pressure state in which the pressure in the space S1 is reduced, the diameter of the precure tread 7 is uniformly distributed over the circumference of the base tire 3 by reducing the diameter. There are no particular restrictions on the material, physical properties, shape, etc., as long as they can be pressed, but care should be taken to withstand the pressure and temperature during vulcanization. In this embodiment, the vulcanization envelope 9 extends over the entire circumference between the bead portions 3b and 3b of the base tire 1 with tread, but the vulcanization envelope 9 is at least the precure tread 7. It only has to be on the outer peripheral surface.

  The main feature of the configuration of the present invention is that a sheet-like fiber body 15 surrounding the exhaust hole 11 is integrally provided on the inner surface of the vulcanization envelope 7 as shown in FIGS. is there. As a material constituting the fiber body 15, woven fabric, non-woven fabric, knitted fabric or the like in which animal fibers, plant fibers, synthetic fibers and the like are entangled and integrated can be used. Such a fiber body 15 can be fixed on the inner surface of the vulcanization envelope 9. For this fixing, for example, heat welding, an adhesive, a double-sided tape or the like can be used.

  In order to bring the precure tread 7 into close contact with the base tire 3, as shown in FIG. 1, first, an unvulcanized cushion rubber 5 is attached to the crown portion 3a of the base tire 3, and the precure tread 7 is disposed thereon. To do. Next, the vulcanization envelope 9 is put on the precure tread 7, and the end 9 a of the vulcanization envelope 9 is disposed between the tread base tire 1 and the bead ring 17. Next, by applying pressure to the internal space S2 of the tread-equipped tire 1, the end portion 9a of the vulcanization envelope 9 is held between the bead portion 3b and the bead ring 17, and the space S1 is sealed from the outside. Is done. Next, the air in the space S1 is sucked by a vacuum pump (not shown) through the valve 13. Thereby, as shown in FIG. 3, the vulcanization envelope 9 is reduced in diameter and the precure tread 7 is pressed against the base tire 3. In this state, the precure tread 7 is vulcanized and bonded to the base tire 3 by placing in a vulcanizing can (not shown) and performing vulcanization under a predetermined temperature and pressure. In place of the vulcanization envelope 9 of this embodiment, when the precure tread 7 is brought into close contact with the base tire 3, an outer envelope (not shown) is provided on the outer surface of the base tire 1 with tread, and the base tire with tread. A vulcanized envelope according to a double envelope system in which inner envelopes (not shown) are respectively disposed on the inner surface portion of 1 and each end of each of the outer envelope and the inner envelope is locked may be applied.

  According to the vulcanization envelope 9 of the present invention, since the sheet-like fibrous body 15 surrounding the exhaust hole 11 is integrally provided on the inner surface, even if the air in the space S1 is sucked through the valve 13, As shown in FIG. 2, the air in the space S <b> 1 is guided to the exhaust hole 11 through a gap G (a gap formed between the fibers) in the fiber body 15. Therefore, in the area near the exhaust hole 11, the inner surface of the vulcanization envelope 9 and the outer surface of the tread-equipped tire 1 are not in close contact with each other, and the air in the space S1 is smoothly sucked. Furthermore, since it is not necessary to provide an air bleeding sheet on the outer peripheral surface of the tread-equipped pedestal tire 1, work man-hours can be reduced. Furthermore, since the fiber body 15 is integrated with the vulcanization envelope 9, there is no need to remove the needle. Further, since the fiber body 15 is integrally provided so as to surround the exhaust hole of the vulcanization envelope 9, the positional displacement of the air vent sheet as in the conventional case does not occur. Furthermore, since the fiber body 15 is integrated with the vulcanization envelope 9, no needle marks remain on the tire surface.

  As shown in FIG. 1, the fibrous body 15 preferably extends at least to a position corresponding to the width direction end 7 a of the precure tread 7. Thereby, the air in the space S1 can be sucked more efficiently.

  Moreover, it is preferable that the fiber body 15 is a nonwoven fabric. Since the nonwoven fabric does not have directionality in strength, elongation, etc., in this way, it is difficult for wrinkles to occur when the vulcanization envelope 5 is reduced in diameter, and as a result, the precure tread 7 is more uniform on the base tire 3. Can be pressed against. In addition, since the nonwoven fabric is superior in air permeability as compared with the woven fabric, the air in the space S1 can be more effectively sucked in this way.

  As is apparent from the above description, according to the present invention, it is possible to provide a vulcanization envelope capable of reducing the number of work steps when the vulcanization envelope is put on a tread-equipped tire.

The cross-section in the width direction when a typical vulcanized envelope according to the present invention is mounted on a tread-equipped tire is shown before the air in the space defined by the vulcanized envelope and the tread-equipped tire is sucked. FIG. FIG. 2 is a developed view showing a part of the inner peripheral surface of the vulcanization envelope shown in FIG. 1. The cross section in the width direction when a typical vulcanized envelope according to the present invention is mounted on a tread-equipped tire is shown after the air in the space defined by the vulcanized envelope and the tread-equipped tire is sucked. FIG.

Explanation of symbols

1 tire with tread 3 tire 5 cushion rubber 7 precure tread 9 vulcanization envelope 11 exhaust hole 13 valve for air intake 15 fiber body 17 bead ring

Claims (3)

An inner diameter larger than the outer diameter of a tread-equipped pedestal tire in which a vulcanized precured tread is disposed on the crown portion of the pedestal via an unvulcanized cushion rubber, and at least the outer surface of the precure tread An annular vulcanization envelope that can cover all of the vulcanization envelope, the vulcanization envelope is attached to the outer surface of the tread-equipped base tire, and the vulcanization envelope and the tread are disposed through an exhaust hole formed in the vulcanization envelope. In a vulcanization envelope that sucks air in a space defined by the attached tire and reduces the pressure in the space and presses the precure tread against the tire,
The vulcanization envelope is characterized in that a sheet-like fiber body surrounding the exhaust hole is integrally provided on an inner surface of the vulcanization envelope.   The vulcanization envelope according to claim 1, wherein the fibrous body extends to a position corresponding to at least a width direction end of the precure tread.   The vulcanization envelope according to claim 1 or 2, wherein the fibrous body is a nonwoven fabric.

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