JP2012101368A - Method of vulcanizing tire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of vulcanizing a tire capable of easily preventing part of rubber of an unvulcanized tire from entering into a space between split molds.SOLUTION: Recesses 44 are formed in portions corresponding to dividing positions of an inner mold 22 on a tread surface 12A of the unvulcanized tire 12, and the unvulcanized tire 12 is disposed within a mold 14 so that the recesses 44 are located in the dividing positions of the inner mold 22. Then, by expanding a bladder 34 of a bladder unit 16 by heated steam to pressurize the inner face of the unvulcanized tire 12, the tread surface 12A is pressed against the mold 14 to perform vulcanization molding.

Description

  The present invention relates to a tire vulcanization method used for manufacturing a pneumatic tire, for example.

  Conventionally, there exists patent document 1 about the tire vulcanization method, for example. In this prior art, the part corresponding to the division | segmentation position of the metal mold | die in a bladder is formed so that the elongation of the tire radial direction at the time of expansion | swelling may become slower than another part. For this reason, vulcanization molding can be performed without causing a part of the rubber of the unvulcanized tire to enter between the split molds before the circumferential ends of the split molds are completely in contact with each other.

JP 2008-273077 A

  However, in patent document 1, the part corresponding to the division | segmentation position of the metal mold | die in a bladder is formed by the uneven thickness part whose thickness of a tire radial direction is larger than another part, and an uneven thickness part is more than other parts. Also, the expansion in the tire radial direction during expansion is slowed down. For this reason, it is necessary to change the bladder. As a result, the configuration of the apparatus becomes complicated and the cost increases.

  In view of the above problems, an object of the present invention is to provide a tire vulcanizing method that can easily prevent a part of rubber of an unvulcanized tire from entering between split molds.

  In the tire vulcanizing method according to the first aspect of the present invention, a radial concave portion is formed on the tread surface of an unvulcanized tire which is a division position of a mold divided into a plurality of split molds along the tire circumferential direction. The mold is disposed on the tread surface side of the unvulcanized tire, and the inner surface of the unvulcanized tire is pressurized by inflating a bladder disposed in the unvulcanized tire. The unvulcanized tire is vulcanized and molded by pressing the surface against the mold.

  In the tire vulcanizing method according to the first aspect, the radial concave portion is formed on the tread surface of the unvulcanized tire which becomes the division position of the mold divided into the plurality of split molds along the tire circumferential direction. Next, the mold is disposed on the tread surface side of the unvulcanized tire, and the bladder disposed in the unvulcanized tire is inflated to pressurize the inner surface of the unvulcanized tire so that the tread surface becomes the mold. Pressed unvulcanized tires are vulcanized. For this reason, due to the radial recesses formed on the tread surface of the unvulcanized tire, the portion corresponding to the mold split position on the tread surface of the unvulcanized tire is more expanded to the mold during expansion than the other portions. Reach slow. As a result, it is possible to vulcanize and mold the rubber without part of the rubber of the unvulcanized tire entering between the split molds before the circumferential ends of the split molds are completely in contact with each other. In addition, since a radial recess may be formed on the tread surface of the unvulcanized tire, it is possible to easily prevent a part of the rubber of the unvulcanized tire from entering between the split molds.

  According to a second aspect of the present invention, in the tire vulcanizing method according to the first aspect, the number of division positions of the mold is the same as the number of the concave portions.

  According to the tire vulcanizing method according to claim 2, since the number of the dividing positions of the mold and the number of the concave portions are the same, a part of the unvulcanized tire is provided between the split molds on the entire circumference of the tread surface. Can easily prevent the rubber from entering.

  According to a third aspect of the present invention, in the tire vulcanizing method according to the first or second aspect, the shape of the concave portion is such that the tread surface not provided with the concave portion is engaged with a dividing position of the mold. It corresponds to the shape.

  According to the tire vulcanizing method of the third aspect, the shape of the concave portion corresponds to the shape in which the tread surface not provided with the concave portion is bitten into the dividing position of the mold. For this reason, it is possible to easily prevent a part of the rubber of the unvulcanized tire from entering between the split molds, and it is also possible to prevent the depression from remaining on the tread surface of the tire after vulcanization molding due to the recess. The shape of the tread surface after molding can be secured.

  According to a fourth aspect of the present invention, in the tire vulcanizing method according to any one of the first to third aspects, the recess is formed by a tire groover.

  In the tire vulcanizing method according to the fourth aspect, since the concave portion is formed by the tire groover, the concave portion can be easily formed in the unvulcanized tire.

  According to a fifth aspect of the present invention, in the tire vulcanizing method according to any one of the first to third aspects, the concave portion is formed by a convex protrusion having a built-in heating wire.

  In the tire vulcanizing method according to the fifth aspect, since the concave portion is formed by the convex protrusion (jig) incorporating the heating wire, the concave portion can be easily formed in the unvulcanized tire.

  According to a sixth aspect of the present invention, in the tire vulcanizing method according to the fifth aspect, the convex protrusion having the heating wire is an O-ring shaped segment used when taking out the unvulcanized tire. Is provided.

  In the tire vulcanization method according to claim 6, since the convex protrusion (jig) with a built-in heating wire is provided in the O-ring shaped segment used when taking out the unvulcanized tire, A recess can be easily formed in the unvulcanized tire.

  Since the tire vulcanizing method according to the first aspect of the present invention is the above method, it is possible to easily prevent a part of the rubber of the unvulcanized tire from entering between the split molds.

  Since the tire vulcanizing method according to the second aspect of the present invention is the above method, it is possible to easily prevent a part of rubber of the unvulcanized tire from entering between the split molds on the entire circumference of the tread surface. .

  Since the tire vulcanizing method according to the third aspect of the present invention is the above method, it is possible to easily prevent a part of rubber of the unvulcanized tire from entering between the split molds, and after vulcanization molding. The tread surface shape can be ensured.

  Since the tire vulcanizing method according to the fourth aspect of the present invention has the above-described configuration, the concave portion of the unvulcanized tire can be easily formed.

  Since the tire vulcanizing method according to the fifth aspect of the present invention is configured as described above, the concave portion of the unvulcanized tire can be easily formed.

  Since the tire vulcanizing method according to the sixth aspect of the present invention has the above-described configuration, the concave portion of the unvulcanized tire can be easily formed.

It is a schematic plane sectional view which shows the state before vulcanization of the vulcanizer of one embodiment in the present invention. It is a perspective view which shows the unvulcanized tire of one Embodiment in this invention. FIG. 3 is an enlarged cross-sectional view taken along the line 3-3 in FIG. 2. It is a general | schematic plane sectional view which shows the vulcanization | cure state of the vulcanizer of one Embodiment in this invention. It is a half side sectional view showing the vulcanization device of one embodiment in the present invention.

  Hereinafter, an embodiment of a tire vulcanizing method according to the present invention will be described with reference to FIGS.

(Vulcanization equipment)
As shown in FIG. 5, the vulcanizing apparatus 10 of this embodiment includes a mold 14 disposed on the outer surface side of the unvulcanized tire 12, and a bladder unit 16 disposed on the inner surface side of the unvulcanized tire 12. It has. Further, the unvulcanized tire 12 is arranged between the mold 14 and the bladder unit 16.

  The mold 14 includes a pair of upper and lower upper molds 18, a lower mold 20, and a middle mold 22. The upper mold 18 and the lower mold 20 correspond to both side surfaces of the unvulcanized tire 12, respectively. The upper mold 18 and the lower mold 20 are supported by substrates 24 and 26, respectively. The upper mold 18 moves upward (in the direction of arrow A in FIG. 5) and downward (in the direction of arrow B in FIG. 5) together with the substrate 24. It is possible.

  The middle mold 22 corresponds to the tread surface 12A of the unvulcanized tire 12, and is divided into a plurality of split molds 22A along the tire circumferential direction. Further, each split mold 22A of the middle mold 22 has a cavity for molding a tread pattern on the inner peripheral surface, and the tire 24 in the tire radial direction (directions of arrows C and D in FIG. 5) via the support portion 28, respectively. It is supported so as to be movable.

  On the other hand, the bladder unit 16 has a pair of upper and lower bladder clamps 30 and 32 and a bladder 34, and the bladder 34 is supported by the bladder clamps 30 and 32. The bladder 34 is made of vulcanized rubber reinforced with a resin fiber cord or a metal cord and is flexible.

  The bladder clamps 30 and 32 are supported by the support shaft 40 so as to be movable in the vertical direction. The lower bladder clamp 32 is provided with a steam inlet 36. By supplying heated steam from the steam inlet 36 to a space closed by the bladder clamps 30, 32 and the bladder 34, the bladder 34 is It comes to expand.

(Unvulcanized tire)
As shown in FIG. 2, the tread surface 12A of the unvulcanized tire 12 continues along the radial direction (direction along the axial direction of the unvulcanized tire 12) at a predetermined interval along the tire circumferential direction. A recess 44 is formed. Moreover, these recessed parts 44 correspond with the division | segmentation position of the middle mold | type 22 divided | segmented into several split mold 22A along the tire circumferential direction shown in FIG.1 and FIG.4.

  As shown in FIG. 3, the cross-sectional shape of the concave portion 44 viewed from the radial direction is a V shape in which the bottom portion and the opening edge portion are arcuate, and the concave portion 44 is not provided with the concave portion 44. The tread surface 12A of the vulcanized tire 12 corresponds to the shape of rubber that is bitten between the split molds 22A. In other words, the volume of the recess 44 is the same as the volume of rubber in which the tread surface 12A of the unvulcanized tire 12 without the recess 44 is caught between the split molds 22A.

  Further, as shown in FIG. 1, the number of recesses 44 formed on the tread surface 12 </ b> A of the unvulcanized tire 12 is the same as the number of division positions of the middle mold 22. That is, the recesses 44 are formed in the tread surface 12A of the unvulcanized tire 12 corresponding to all the division positions of the middle mold 22.

(Tire vulcanization method)

  When the unvulcanized tire 12 is vulcanized by the vulcanizing apparatus configured as described above, first, the concave portion 44 is formed in a portion to be a division position of the middle mold 22 of the tread surface 12A of the unvulcanized tire 12. As a method of forming the recess 44 on the tread surface 12A of the unvulcanized tire 12, a method of forming by a tire groove used for cutting a tread pattern of the tire or a method of forming a convex protrusion (jig) incorporating a heating wire is used. There is a way to do it. In addition, you may provide the convex-shaped protrusion (jig) which incorporated the heating wire in the segment used as the O-ring shape used when taking out the unvulcanized tire 12. FIG.

  Next, the bladder unit 16 contracted by the bladder 34 is arranged inside the unvulcanized tire 12 (inside in the radial direction) and the unvulcanized tire 12 is arranged in the mold 14. At this time, in this embodiment, as shown in FIG. 1, the position of the recess 44 formed on the tread surface 12A of the unvulcanized tire 12 is arranged between the division positions of the middle mold 22, that is, between the adjacent split molds 22A. To do.

  Next, as shown in FIG. 4, the circumferential ends of the split molds 22A of the middle mold 22 are brought into contact with each other, and the bladder 34 of the bladder unit 16 is expanded by heated steam. As a result, the inner surface of the unvulcanized tire 12 is pressurized and heated by the bladder 34, and the tread surface of the unvulcanized tire 12 is pressed against the mold 14 to be molded.

  At this time, in the present embodiment, the position of the recess 44 formed on the tread surface 12A of the unvulcanized tire 12 is the division position of the middle mold 22. For this reason, the part corresponding to the division position of the middle mold 22 on the tread surface 12A of the unvulcanized tire 12 arrives at the middle mold 22 at the time of expansion more slowly than the other parts. For this reason, it vulcanizes and molds, without a part of rubber | gum of the unvulcanized tire 12 entering between each split mold 22A.

(Action / Effect)
As described above, in the present embodiment, since the radial recesses 44 are formed on the tread surface 12A of the unvulcanized tire 12 that is the division position of the middle mold 22, one unvulcanized tire 12 is provided between the split molds 22A. The rubber of the part does not enter. As a result, it is possible to easily and inexpensively prevent a part of the rubber of the unvulcanized tire 12 from entering between each split mold 22A.

  In the present embodiment, the number of division positions of the divided middle mold 22 is the same as the number of recesses 44. For this reason, it is possible to easily prevent a part of the rubber of the unvulcanized tire 12 from entering between the split molds 22A on the entire circumference of the tread surface 12A of the unvulcanized tire 12.

  In the present embodiment, the cross-sectional shape of the concave portion 44 viewed from the radial direction corresponds to the shape in which the tread surface 12A of the unvulcanized tire 12 without the concave portion 44 is bitten into the division position of the middle mold 22. For this reason, it is possible to easily prevent a part of the rubber of the unvulcanized tire 12 from entering between each split mold 22A, and it is possible to prevent the depression 44 from remaining on the tread surface of the tire after vulcanization molding. Therefore, the tread surface shape can be secured.

  In the present embodiment, the concave portion 44 is formed on the tread surface 12A of the unvulcanized tire 12 by a convex protrusion (jig) incorporating a tire groover or heating wire. For this reason, the recessed part 44 can be formed easily. Furthermore, the concave portion 44 can be formed more easily by providing a convex protrusion (jig) containing a heating wire in a segment having an O-ring shape used when the unvulcanized tire 12 is taken out.

(Other embodiments)
The embodiments of the present invention have been described above with reference to the embodiments. However, these embodiments are merely examples, and various modifications can be made without departing from the scope of the invention. It goes without saying that the scope of rights of the present invention is not limited to these embodiments. For example, the method of forming the recess 44 on the tread surface 12A of the unvulcanized tire 12 is not limited to the method using a tire groove or a convex protrusion (jig) with a built-in heating wire, and may be formed by other methods. Good. Moreover, you may provide the convex-shaped protrusion (jig) which incorporated the heating wire in addition to the segment used as the O-ring shape used when taking out the unvulcanized tire 12.

  Moreover, in the said embodiment, although the cross-sectional shape seen from the radial direction of the recessed part 44 was made into the V shape where the bottom part and the opening edge became circular arc shape, the cross-sectional shape seen from the radial direction of the recessed part 44 was semicircle. It is good also as other shapes, such as a shape.

  Moreover, in the said embodiment, although the recessed part 44 was formed in tread surface 12A of the unvulcanized tire 12 corresponding to all the division | segmentation positions of the intermediate mold 22, it replaces with this and a part of rubber | gum of an unvulcanized tire enters. The concave portion 44 may be formed only on the tread surface 12A of the unvulcanized tire 12 corresponding to the predetermined division position that is easy.

DESCRIPTION OF SYMBOLS 10 Curing apparatus 12 Unvulcanized tire 12A Tread surface of unvulcanized tire 14 Mold 16 Bladder unit 18 Upper mold 20 Lower mold 22 Medium mold 22A Split mold 34 Bladder 44 Concave part of unvulcanized tire

Claims (6)

  A concave portion in a radial direction is formed on a tread surface of an unvulcanized tire which is a division position of a mold divided into a plurality of split molds along the tire circumferential direction, and the metal is formed on the tread surface side of the unvulcanized tire. A mold is disposed, and a bladder disposed in the unvulcanized tire is inflated to pressurize the inner surface of the unvulcanized tire, thereby pressing the tread surface against the mold and vulcanizing the unvulcanized tire. Tire vulcanization method to be molded.   The tire vulcanization method according to claim 1, wherein the number of division positions of the mold is the same as the number of the recesses.   The tire vulcanization method according to claim 1 or 2, wherein the shape of the concave portion corresponds to a shape in which the tread surface not provided with the concave portion is bitten by a division position of the mold.   The tire vulcanization method according to claim 1, wherein the recess is formed by a tire groover.   The tire vulcanization method according to any one of claims 1 to 3, wherein the recess is formed by a protrusion having a built-in heating wire.   The tire vulcanization method according to claim 5, wherein the convex protrusion incorporating the heating wire is provided in a segment having an O-ring shape used when the unvulcanized tire is taken out.