JP2005161717A - Mold for molding tire, plug used in vent hole of the mold and tire manufactured using the mold - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a mold for molding a tire capable of molding the tire without forming spews to the surface of the tire, capable of avoiding the spew removing work of tire finishing process work and capable of enhancing the appearance of the product tire, a plug used in the vent hole of the mold for molding the tire and the tire manufactured using the mold for molding the tire. <P>SOLUTION: In this emobodiment, the vent hole 2 has a large diameter recessed part 2a piercing the mold 1 from the inner surface 1a of the mold 1 toward the outside and a medium diameter recessed part 2b formed thereto so as to provide difference in level and a detachable plug 3 is mounted in the vent hole 2. The plug 3 is constituted of a plug main body 4 formed of a metal material such as stainless steel or the like and a deformable plug core body 6 comprising a rubbery elastomer such as a silicone rubber or the like detachably fitted in the fitting hole 5 having the difference in level between the recessed parts 4a and 4b formed to the center part of the plug main body 4. The exhaust passage 7 communicating with the exhaust cylindrical part 2c of the vent hole 2 is formed to a part of the periphery of the fitting hole 5. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a tire molding die, a plug used for a vent hole of a tire molding die, and a tire manufactured using the tire molding die, and more particularly, a tire surface during tire vulcanization molding. Tire molding mold that can be molded without generating spew, improve the tire finishing process work, and improve the appearance of the product tire, plug used in the vent hole of the tire molding mold, and this tire The present invention relates to a tire manufactured using a molding die.

  Conventionally, a tire molding die used in a tire vulcanization process has a vent hole in order to exhaust air accumulated between the inner surface of the die and an unvulcanized tire during tire vulcanization molding to the outside of the die. A large number of narrow exhaust holes called “a” are formed.

  These numerous vent holes are generally machined into locations where mold air is likely to remain. For example, the vent holes are machined into 8 or more locations on the same circumference of the die corresponding to bead rings, rims, side portions, etc. The number of circumferential rows varies depending on the tire shape.

  Further, one or more vent holes in the design block of the mold surrounded by the groove of the tire tread portion are processed (for example, see Patent Document 1 and Patent Document 2).

  However, when a tire is vulcanized and molded with a mold having a large number of vent holes, the vulcanized rubber flows into the large number of vent holes, and a large number of spider-like protrusions (spews) are generated on the surface of the product tire.

For this reason, in the tire finishing process after molding the tire, it is indispensable to excise the above spew, which not only hinders workability and productivity, but also a lot of excised spew scraps are scattered to deteriorate the working environment. There was a problem that it was difficult to improve the appearance of the product tire.
Japanese Utility Model Publication No. 7-33615 Japanese Utility Model Publication No. 62-13611

  This invention has been devised by paying attention to such conventional problems, can be molded without generating spew on the tire surface during tire vulcanization molding, can eliminate the spew removal work of the tire finishing process work, Manufactured by using a tire molding die that can improve the working environment and improve the appearance of the product tire, a plug used in a vent hole of the tire molding die, and the tire molding die It is an object of the present invention to provide a tire.

  In order to achieve the above object, the tire molding die according to the present invention abuts each of the vent holes of the die with a concave portion having a stepped portion and a cylindrical portion that fits into an exhaust tube portion of the vent hole. A plug composed of a head part is detachably mounted, and the plug body forms a fitting hole having a step in the center part of the head part and the cylindrical part, and a part around the fitting hole is formed. An exhaust passage communicating with the exhaust tube portion of the vent hole is formed, and the exhaust passage is opened in the fitting hole formed in the plug body before the tire is inserted into the mold, and the tire pressure after the tire is inserted. The gist is that the deformable plug core body made of a rubber-like elastic body for closing the exhaust passage is detachably mounted.

  Further, the plug used in the vent hole of the mold for molding a tire according to the present invention is a plug that is detachably attached to each vent hole of the mold, and the plug body includes a plug body formed of a metal material. And a deformable plug core body made of a rubber-like elastic body that is removably fitted into a fitting hole having a step formed in the center of the plug body, and a part around the fitting hole In addition, an exhaust passage communicating with the exhaust cylinder portion of the vent hole is formed, and the plug core body opens the exhaust passage before inserting the tire into the mold and closes the exhaust passage by the pressure of the tire after inserting the tire. The gist is that it is configured in the shape to be made.

  Here, the plug body is made of a stainless material, and the plug core is made of silicone rubber.

  Further, the gist of the tire manufactured using the tire molding die of the present invention is that crater-like minute protrusions are formed on the tire surface.

  In this way, a large number of vent holes formed in the mold are detachably mounted with plugs that open the vent holes before inserting the tire into the mold and close the vent holes by the tire pressure after inserting the tire. Therefore, it is possible to mold without generating spew on the tire surface at the time of tire vulcanization molding, it is possible to omit the spew removal work of the tire finishing process work, improve the working environment, and improve the appearance of the product tire I can do it.

  Since the present invention is configured as described above, it can be formed without generating spew on the tire surface during tire vulcanization molding, the spew removing operation of the tire finishing process can be omitted, and spew scraps can be generated. Therefore, the working environment can be improved, the cost of the material can be reduced, and the appearance of the product tire can be further improved.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

  FIG. 1 is an enlarged cross-sectional view of a vent hole portion of a tire molding die embodying the present invention, wherein 1 is a mold, 2 is a vent hole, and there are a number of vent holes 2 at predetermined positions of the mold 1. The air Q that is formed and accumulated between the mold 1 and the tire W at the time of tire vulcanization molding is exhausted to the outside of the mold.

  In the present embodiment, each of the vent holes 2 is formed with a large-diameter concave portion 2a penetrating from the inner surface 1a of the mold 1 to the outside and an intermediate-diameter concave portion 2b. A detachable plug 3 as shown in FIGS. 1 and 2 is installed in the hole 2.

  The plug 3 is detachably fitted into a fitting hole 5 having a step between a plug body 4 formed of a metal material such as stainless steel and recesses 4a and 4b formed in the center of the plug body 4. A deformable plug core body 6 made of a rubber-like elastic body such as silicone rubber is formed. A part of the periphery of the fitting hole 5 is provided with a vent hole 2 as shown in FIGS. An exhaust passage 7 communicating with the cylinder portion 2c is formed.

  The plug core body 6 is configured to open the exhaust passage 7 before the tire W is inserted into the mold 1 and close the exhaust passage 7 by the pressure P of the tire W after the tire W is inserted. . That is, the plug core body 6 is slightly higher than the height H of the large-diameter recess 4a of the plug body 4 and slightly smaller than the diameter D of the recess 4a (for example, about 0.1 mm). When the tire W is inserted into the mold 1, the head portion 6a is shown by the pressure P (crimping force) of the tire W when the tire W is inserted into the mold 1. As shown in FIG. 2, the exhaust passage 7 is closed by gradually expanding and deforming in the radial direction.

  Therefore, while the head portion 6a is gradually deformed, the air Q existing between the inner surface 1a of the mold 1 and the tire W as shown in FIG. The gas is exhausted outside the mold 1 through the exhaust passage 7.

  The exhaust passage 7 needs to communicate between the inside and the outside of the mold 1, but the fitting hole 5 does not necessarily pass through the mold 1 and can be fitted with the plug core body 6. The shape is not particularly limited as long as it has a diameter. Moreover, although the exhaust passage 7 is formed at two symmetrical positions in the embodiment of the present invention, the number of exhaust passages 7 is not particularly limited.

  The tire W molded using the tire molding die 1 with the plug 3 mounted in the vent hole 2 as described above has crater-shaped minute protrusions X on the tire surface as shown in FIG. Therefore, the tire surface can be molded without generating spew and the appearance of the product tire can be improved.

FIG. 2 is an enlarged cross-sectional view of a vent hole portion of a tire molding die embodying the present invention, showing a state before the plug core body is deformed. FIG. 3 is an enlarged cross-sectional view of a vent hole portion of a tire molding die embodying the present invention, and is a cross-sectional view in a state where an exhaust passage after deformation of a plug core body is closed. It is sectional drawing of a plug main body. It is AA arrow sectional drawing of FIG. It is a partial perspective view of the tire manufactured with the metal mold for tire fabrication of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Mold 1a Inner surface 2 Vent hole 2a Large diameter recessed part 2b Medium diameter recessed part 2c Exhaust cylinder part 3 Plug 4 Plug main body 4a Large diameter recessed part of plug main body 4b Medium diameter recessed part of plug main body 5 Fitting hole 7 Exhaust passage H Height of concave part with large diameter D Diameter of concave part

Claims (4)

In tire molding molds that are provided with a number of vent holes for exhausting air accumulated between the mold and the tire during tire vulcanization molding,
Each of the vent holes of the mold is detachably mounted with a plug composed of a cylindrical portion that fits into the exhaust tube portion of the vent hole and a head portion that abuts against a concave portion having a step. A fitting hole having a step is formed in the central part of the head part and the cylindrical part, and an exhaust passage communicating with the exhaust cylinder part of the vent hole is formed in a part of the periphery of the fitting hole, and the plug body A deformable plug core made of a rubber-like elastic body that opens the exhaust passage before inserting the tire into the mold and closes the exhaust passage by the tire pressure after inserting the tire into the fitting hole formed in Tire molding mold that can be mounted. A plug that is removably attached to each vent hole of a mold, and this plug can be attached to and detached from a plug body formed of a metal material and a fitting hole having a step formed at the center of the plug body. A deformable plug core body made of a rubber-like elastic body fitted into the plug hole, and an exhaust passage communicating with the exhaust tube portion of the vent hole is formed in a part of the periphery of the fitting hole, and the plug core The body is a plug used for a vent hole of a mold for molding a tire that is configured to open the exhaust passage before inserting the tire into the mold and close the exhaust passage by the pressure of the tire after inserting the tire. The plug used for a vent hole of a mold for molding a tire according to claim 2, wherein the plug body is made of a stainless material, and the plug core is made of silicone rubber. A tire in which crater-like minute protrusions are formed on the tire surface using the tire molding die according to claim 1.

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