JP5837741B2 - Tire vulcanization method - Google Patents

Description

  The present invention relates to a tire vulcanization method for obtaining a product tire having a color rubber line having a width of, for example, 10 mm or less, which extends in an annular shape on a side surface of the tire, for example, for decoration. , Which effectively prevents unintended deformation and displacement of the unvulcanized color rubber line material during vulcanization molding of raw tires, the desired shape, dimensions, etc. A technique for forming a uniform color rubber line over the entire circumference is proposed.

  When forming a color rubber line, for example, a white line, on the side of the product tire, the color rubber line material is usually set at a predetermined position of a green tire molded on a cylindrical molding drum, and then The raw tire removed from the molding drum is inserted into a vulcanizer, and when the raw tire is vulcanized, the raw tire is relatively expanded and deformed by a vulcanization bladder. In general, the outer surface is adhered to the inner peripheral surface of the vulcanization mold sufficiently uniformly.

  However, in this conventional technology, when raw tire vulcanization molding is performed, the raw tire set by sticking a color rubber line material at a predetermined location is put into a closed vulcanization mold with a vulcanization bladder. On the other hand, since it is unavoidable to cause relatively large expansion and deformation, unintentional large deformation and displacement may occur in the color rubber line material itself during this expansion and deformation process of the raw tire. In a finished product tire, the color rubber line often wobbles or the boundary of the color rubber line is blurred.

  This invention pays attention to the fact that the meandering of the color rubber line of the prior art is caused by the deformation of the color rubber line material accompanying the large deformation of the raw tire by the vulcanization bladder. The purpose of this is to remove the meandering of the color rubber line in the product tire, blurring of the boundary, etc., and accurately place the color rubber line at the expected position. It is in providing the tire vulcanization method which can form.

The tire vulcanization method of the present invention is a method for obtaining a product tire having a color rubber line extending in an annular shape at a required position on the side surface of the tire, and an outer periphery corresponding to the inner peripheral surface shape of the product tire Volume of cavity defined between a rigid core made of metal that can be disassembled and assembled and a vulcanization mold in a mold-clamping posture, for example, having a surface shape and molding a raw tire on the outer peripheral surface A raw tire having a volume of 95% or more and 98% or less is molded on the outer peripheral surface of the rigid core, and a color rubber line material is affixed in an annular shape to the side of the raw tire. Is inserted into the vulcanization mold together with the rigid core, and the raw tire and the rigid core are thermally expanded under heating of the rigid core and the vulcanization mold, and the raw tire is vulcanized in a sufficiently small deformation state. Mold Vulcanized by close contact with the surface, an annular sticking color rubber line material, have rows by a machine set of unvulcanized rubber rings obtained by forming in advance an annular, said color rubber line material, the The color rubber line of the product tire is formed without being removed after vulcanization while being vulcanized in a state of being disposed on the outermost surface of the side surface of the green tire .
In addition, here, the color rubber line material stuck on the side surface of the raw tire constitutes a part of the raw tire.

The width of the collar rubber line on product tire 2mm or more, it is preferable to 400mm or less.

  In the tire vulcanizing method of the present invention, the volume of the raw tire molded on the outer peripheral surface of the rigid core that is made of a metal material or the like and can be disassembled and assembled is 95% or more and 98% or less of the volume of the vulcanization cavity. The raw tire is molded and vulcanized by the vulcanization mold based on the adhesion of the raw tire to the inner surface of the vulcanization mold due to the rigid core during the vulcanization molding and the thermal expansion of the raw tire. The amount of deformation of the raw tire itself during the vulcanization molding of the raw tire can be reduced as compared with the prior art using a vulcanization bladder. Due to the flow of the color rubber line material, the deformation amount of the color rubber line material stuck in an annular shape can also be kept small and the color rubber line material can be maintained at the expected position. Thus, it is possible to sufficiently prevent meandering of the color rubber line, blurring of the boundary of the color rubber line, and the like in the vulcanized product tire.

  Here, the volume of the raw tire is set to 95% or more of the cavity volume in order to ensure sufficient adhesion to the inner surface of the vulcanization mold of the raw tire based on the thermal expansion of the rigid core and the raw tire. On the other hand, setting the volume to 98% of the cavity volume prevents damage to the rigid core due to thermal expansion of the raw tire, and also to the mold splitting surface when clamping the vulcanization mold This is to prevent biting of the raw tire.

In such a method, the annular sticking of the color rubber line material is applied to an unvulcanized ribbon-like rubber strip, for example, a width in the range of 5-30 mm and a thickness in the range of 0.2-5 mm When it is done by laminating and winding rubber strips, the color rubber line material can be placed at a predetermined position with high dimensional accuracy without preparation for the color rubber line material in advance, regardless of the size of the tire to be molded. It can be attached in an annular shape.
On the other hand, when carrying out circular sticking of color rubber line material by holding and sticking a set of unvulcanized rubber ring formed in advance in a ring shape by a machine such as a robot, it is simple or general purpose. Although installation of the machine is unavoidable, the color rubber line material can be stuck in a circular shape with high dimensional accuracy at a predetermined position in the same manner as described above.

  By the way, in this method, when the width of the color rubber line on the product tire is 2 mm or more and 400 mm or less, the tire appearance quality is improved, and the customer's selection range increases. It can also be used as an indicator for judging tire performance only by looking.

It is an approximate line longitudinal section showing an embodiment of this invention about a half part of a vulcanization mold. It is a basic-line longitudinal cross-sectional view which shows other embodiment about the half part of a vulcanization mold.

Embodiments of the present invention will be described below based on the drawings.
In FIG. 1 showing an embodiment using a so-called split mold in a mold-clamped state, 1 shows a rigid core made of a metal material or the like, which can be disassembled into a plurality of segments and assembled. Under the assembled state, the rigid core 1 has an outer peripheral surface shape corresponding to the inner peripheral surface shape of a product tire vulcanized and molded in a mold.

  Here, a green tire 2 is molded on the outer peripheral surface of such a rigid core 1, and the volume of the green tire 2 on the rigid core 1 is changed to a vulcanization mold 3, in the figure, upper and lower side molds 4, 5. The volume of the cavity 7 defined between each sector mold 6 and the rigid core 1 is 95% or more and 98% or less, and each side surface of the raw tire 2 has, for example, a width and a thickness. The color rubber line material 8 that can be 3.5 mm and 0.6 mm is provided in an annular shape within the range of the above volume ratio.

  After that, the raw tire 2 together with the rigid core 1 is inserted into the vulcanization mold 3 as shown in the figure, and the rigid core 1 and the vulcanization mold 3 are clamped as shown in the figure. By heating the sulfur mold 3 and thermally expanding the raw tire 2 and the rigid core 1, the green tire 2 is brought into close contact with the inner surface of the vulcanizing mold 3 to be molded and vulcanized.

  According to such a vulcanization method, the color rubber line material 8 adhered to the side portion of the green tire 2 is in close contact with the inner surface of the vulcanization mold 3 under slight deformation due to thermal expansion and vulcanized. Therefore, the color rubber line material does not undergo the large deformation, displacement, etc., as described in the prior art, and this sufficiently prevents the unintended rubber flow of the color rubber line material 8. The color rubber can be disposed sufficiently accurately at the intended position of the product tire.

  After the raw tire 2 on the rigid core 1 is vulcanized and molded in this way, the upper platen 9 and the top plate 10 are moved up and displaced together with the upper side mold 4, and the sector molds 6 are expanded in diameter accordingly. By displacing, the vulcanization mold 3 can be opened, and the vulcanized tire can be taken out of the vulcanization mold 3 together with the rigid core 1.

  The vulcanized tire can be separated from the rigid core 1 by disassembling the rigid core 1 into a plurality of segments and extracting it from the tire.

Further, in FIG. 2 showing an embodiment using a so-called full mold in a mold-clamping posture, 1 and 2 respectively indicate the same rigid core and the raw tire on the rigid core as described above, and 21 and 22 respectively. The upper mold and the lower mold are shown.
Here, the vulcanization mold 23 includes upper and lower molds 21 and 22, and the upper and lower molds 21 and 22 are attached to the platen type upper and lower heating members 25 and 26 of the vulcanizer 24. Heated.

  Again, the green tire 2 molded on the outer peripheral surface of the rigid core 1 includes a color rubber line material 8 in which the volume is affixed to each side of the green tire 2 in an annular shape, and is clamped 95% or more and 98% or less of the volume of the cavity 7 defined between the vulcanizing mold 23 in the state and the rigid core 1, and thereby the vulcanizing mold 23 and the vulcanizing mold 23 in the vulcanization molding of the raw tire 2. By heating the rigid core 1, the rigid core 1 and the raw tire 2 are thermally expanded to bring the outer surface thereof into close contact with the inner surface of the vulcanization mold 23 under slight deformation of the raw tire 2.

  Therefore, according to this embodiment using the full mold, it is also possible to prevent the unexpected rubber flow of the color rubber line material 8 and arrange the color rubber line at a required position of the product tire with sufficient accuracy. it can.

  Then, the vulcanized product tire can be taken out from the vulcanization mold 23 under the mold opening state by moving the upper mold 21 upwardly under the action of the vulcanizer 24. The separation of the product tire taken out together with the rigid core 1 from the rigid core 1 is performed by disassembling the rigid core 1 into a plurality of segments and extracting each of the segments from the tire in the required order. Can do.

DESCRIPTION OF SYMBOLS 1 Rigid core 2 Raw tire 3,23 Vulcanization mold 4 Upper side mold 5 Lower side mold 6 Sector mold 7 Cavity 8 Color rubber line material 9 Upper platen 10 Top plate 21 Upper mold 22 Lower mold 24 Vulcanizer 25, 26 Heating Element

Claims (2)

In a method of vulcanizing a product tire having a color rubber line extending annularly on the side surface of the tire,
95% or more of the volume of the cavity defined between the rigid core on which the raw tire is molded on the outer peripheral surface and the vulcanization mold, the outer peripheral surface shape corresponding to the inner peripheral surface shape of the product tire A raw tire having a volume of 98% or less is molded on the outer peripheral surface of the rigid core, and a color rubber line material is affixed in an annular shape to the side of the raw tire, and then the raw tire is added together with the rigid core. It is inserted into the vulcanization mold, the raw tire and the rigid core are thermally expanded under heating of the rigid core and the vulcanization mold, and the raw tire is attached to the inner surface of the vulcanization mold and vulcanized.
Color rubber line annular sticking material, have rows by a machine set of unvulcanized rubber rings obtained by forming in advance an annular,
The color rubber line material is vulcanized in a state of being disposed on the outermost surface of the side surface of the green tire, and forms the color rubber line of the product tire without being removed after vulcanization. .   The tire vulcanization method according to claim 1, wherein the width of the color rubber line on the product tire is 2 mm or more and 400 mm or less.

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