JP2006015626A - Mold for molding tire, plug used in vent hole of the mold, and tire produced by using the mold - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a mold for molding a tire which can improve tire finishing process work and the appearance of a finished tire, a plug used in the vent hole of the mold, and the tire produced by using the mold. <P>SOLUTION: A communicating conduit 6 with a hollow cross section formed from the middle of the end surface of a cylindrical part 4y is formed in the central part of a plug main body 4 and communicates with the exhaust tube part 2b of a middle diameter of each vent hole 2. On the upper surface of the head part 4x of the plug main body 4, a slit 8 for exhaust which opens the vent hole 2 before an unvulcanized tire W is inserted into the mold 1 and closes the vent hole 2 by the contact pressure of the unvulcanized tire W after the insertion of the unvulcanized tire W is formed. The slit 8 is preferably formed to make an inclination angle α of 10-80° to the upper surface S of the head part 4x, and the clearance k of the slit 8 is preferably 0.5-1.5 mm. <P>COPYRIGHT: (C)2006,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 for exhausting air accumulated between the inner surface of the die and an unvulcanized tire to the outside of the die during tire vulcanization molding. A number of narrow exhaust holes (depending on the type of tire, approximately 0.5 mm to 20 mm) are formed.

  The large number of vent holes are processed in locations where mold air is likely to remain. Generally, 300 to 1500 pieces in the tread part, and bead rings, rims, side parts, etc. are on the same circumference of the mold. 4 or more are processed, and the number of circumferential rows varies depending on the tire shape. Further, at least one vent hole in the mold design block surrounded by the groove of the tire tread portion is processed (see, for example, 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 remove the above spew, which not only hinders workability and productivity, but also a lot of scraped spew scraps are scattered around, deteriorating the working environment, Furthermore, there was a problem of deteriorating the appearance of the product tire.
Japanese Utility Model No.7-33615 microfilm Japanese Utility Model No. 62-13611 microfilm

  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, according to the present invention, a tire molding die according to the present invention has a plug body detachably attached to each vent hole, and the plug body is inserted into an unvulcanized tire before being inserted into the mold. The gist is that the vent hole is opened, and after inserting the unvulcanized tire, an exhaust slit for closing the vent hole is formed by the contact pressure of the unvulcanized tire.

  Here, it is also possible to detachably attach a plug body to each vent hole via a plug holder.

  Further, the plug used for the vent hole of the tire molding die of the present invention is a plug used for the vent hole of the tire molding die that is detachably attached to the vent hole formed in the die, The plug body is composed of a cylindrical portion that fits into the exhaust cylinder portion of the vent hole, and a head portion that abuts against a concave portion having a step, and forms a communication path that communicates with the exhaust cylinder portion in the cylindrical portion, The gist of the invention is that an exhaust slit is formed on the upper surface of the head portion to communicate or block the communication passage and the inside of the mold.

  Here, the plug body can be integrally assembled with a plug holder that fits into the exhaust tube portion of the vent hole, and the exhaust slit formed on the upper surface of the head portion is linear, spiral. Any one of a shape, a polygonal shape, and a circular shape is used.

  The exhaust slit formed on the upper surface of the head portion is formed at an inclination angle of 10 ° to 80 ° with respect to the upper surface of the head portion. It is preferable to set to 5 to 1.5 mm.

  Furthermore, a V groove may be formed on the upper surface of the head portion of the exhaust slit, and the plug body and the plug holder are integrally formed of a heat resistant resin material.

  Further, a tire manufactured using the tire molding die according to the present invention uses a tire molding die in which a plug body is detachably attached to a number of vent holes formed in the die. A crater-like vent plug mark is formed on the surface.

  In this way, the plug body is detachably attached to each vent hole, and the vent hole is opened in the plug body before the unvulcanized tire is inserted into the mold, and the tire contact after the unvulcanized tire is inserted. By forming an exhaust slit that closes the vent hole by pressure, it can be molded without generating spew on the tire surface during tire vulcanization molding, eliminating the spew removal work of the tire finishing process work and improving the work environment It is possible to improve the appearance of the product tire.

  The present invention opens the vent holes before inserting the unvulcanized tire into the mold, and contacts the unvulcanized tire after inserting the unvulcanized tire into the numerous vent holes formed in the mold as described above. By detachably attaching a plug body with an exhaust slit that closes the vent hole by pressure, it can be molded without generating spew on the tire surface during tire vulcanization molding, and spew removal work in the tire finishing process In addition, since the generation of spew waste is small, 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 a partially enlarged cross-sectional view of a tire molding die embodying the present invention. The die 1 is accumulated between the die 1 and an unvulcanized tire W during tire vulcanization molding. A large number of vent holes 2 for exhausting air are formed.

  In this embodiment, each vent hole 2 has a large-diameter exhaust cylinder portion 2a penetrating from the inner surface 1a of the mold 1 to the outside and a medium-diameter exhaust cylinder portion 2b connected via a tapered hole 2c. In each of the vent holes 2, a plug holder 3 integrally formed of a detachable heat resistant resin (for example, polytetrafluoroethylene: PTFE), and a plug body 4 fitted to the plug holder 3 are provided. Is attached.

  As shown in FIG. 2, the plug holder 3 is formed by a cylindrical body 5 that fits into the large-diameter exhaust cylinder portion 2a of each vent hole 2, and the distal end side 5a of the cylindrical body 5 is tapered. It is formed in a tapered shape toward the hole 2c and the medium-diameter exhaust tube portion 2b. In the center portion of the plug holder 3, a large diameter hole portion 3a and a medium diameter hole portion 3b into which the plug body 4 is fitted are formed through a step portion 3c, and the large diameter hole portion 3a and the medium diameter hole portion are formed. As shown in FIG. 3, the plug main body 4 fitted to 3b is composed of a head portion 4x fitted to the large-diameter hole portion 3a and a cylindrical portion 4y fitted to the medium-diameter hole portion 3b. Yes.

  In addition, a communication passage 6 having a concave cross section formed from the center of the end surface of the cylindrical portion 4y is formed at the center portion of the plug body 4, and the communication passage 6 is an exhaust cylinder portion 2b having a medium diameter in each vent hole 2. Communicating with Further, the vent hole 2 is opened on the upper surface of the head portion 4x of the plug body 4 before the unvulcanized tire W is inserted into the mold 1, and the unvulcanized tire is inserted after the unvulcanized tire W is inserted. An exhaust slit 8 for closing the vent hole 2 by the contact pressure of W is formed.

  The exhaust slit 8 communicates or blocks the inside of the mold 1 and the medium-diameter exhaust cylinder portion 2b of each vent hole 2. In this embodiment, the exhaust slit 8 is formed in a linear shape, It is also possible to form either a polygonal shape or a circular shape. The exhaust slit 8 is preferably formed at an inclination angle α of 10 ° to 80 ° with respect to the upper surface S of the head portion 4x, and the gap k of the exhaust slit 8 is 0.5 to 1.5 mm. It is desirable to be in the range. Further, a V-groove 7 may be formed on the upper surface of the head portion 4x where the exhaust slit 8 is formed.

  If the inclination angle α is less than 10 °, it reacts sensitively to the contact pressure of the unvulcanized tire W, and the exhaust slit 8 is closed by a slight contact, so that the air in the mold 1 is closed. There is a problem that it is difficult to escape, and when it exceeds 80 °, there is a problem that the exhaust slit 8 is difficult to close. Further, when the gap k of the exhaust slit 8 is less than 0.5 mm, there is a problem that the exhaust passage is narrow and difficult to exhaust, and when it exceeds 1.5 mm, the exhaust slit 8 is difficult to close. Since the rubber of the unvulcanized tire W easily flows, there is a problem that the spew (pattern) becomes large.

  In the above-described embodiment, the plug body 4 is attached to each vent hole 2 via the plug holder 3. However, the present invention is not limited to this embodiment, and the plug body 4 is directly attached to each vent hole 2. Is also possible.

  Thus, before the unvulcanized tire W is inserted into the mold 1 as shown in FIGS. 4 and 5, the vent holes 2 are opened to the numerous vent holes 2 formed in the mold 1. After insertion of the vulcanized tire W, the plug body 4 having the exhaust slit 8 that closes the vent hole 2 by the contact pressure of the unvulcanized tire W is detachably attached, so that the tire surface is In addition, it can be molded without generating spew, can eliminate the spew removal work of the tire finishing process work, and can reduce the spew waste, so that the work environment can be improved and the cost of the material can be reduced. Is possible.

  Further, when the unvulcanized tire W is molded by the mold 1 in which the plug body 4 having the exhaust slits 8 is installed in the numerous vent holes 2 as described above, as described above, Since the vent hole 2 is opened through the exhaust slit 8 before the unvulcanized tire is inserted, the air between the mold 1 and the unvulcanized tire W is exhausted to the outside through the vent hole 2. In addition, since the vent hole 2 is closed by the contact pressure of the unvulcanized tire W after the unvulcanized tire is inserted, the molten vulcanized rubber at the time of tire vulcanization does not flow into the vent hole 2. There is no occurrence of spew, and a tire W having a good appearance and having a crater-like vent plug mark 9 as shown in FIG. 6 can be manufactured.

It is a partial expanded sectional view of the metal mold | die for tire shaping which implemented this invention. It is an expanded sectional view of the plug holder with which it attaches to the vent hole of a metal mold | die. It is an expanded sectional view of the plug main body of this invention. FIG. 4 is an enlarged cross-sectional view in which a plug body is mounted on a mold vent hole via a plug holder. 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 exhaust cylinder part 2b Medium-diameter exhaust cylinder part 2c Tapered hole 3 Plug holder 3a Large-diameter hole part 3b Medium-diameter hole part 3c Step part 4 Plug main body W Tire 4x Head part 4y Tubular part 5 Tubular body 5a Tip side 6 Communication path 7 V groove 8 Exhaust slit 9 Vent plug trace k Gap

Claims (10)

At the time of tire vulcanization molding, in the mold for tire molding comprising a number of vent holes for exhausting the air accumulated between the mold and the unvulcanized tire,
A plug body is detachably attached to each vent hole, and the vent hole is opened before inserting the unvulcanized tire into the mold, and the unvulcanized tire is contacted after inserting the unvulcanized tire. A mold for molding a tire, wherein an exhaust slit for closing a vent hole by pressure is formed. The tire molding die according to claim 1, wherein a plug main body is detachably attached to each vent hole via a plug holder. A plug used for a vent hole of a tire molding die that is detachably attached to a vent hole formed in a die, and the plug body includes a cylindrical portion that fits into an exhaust cylinder portion of the vent hole, The head portion is in contact with a concave portion having a step, and a communication passage communicating with the exhaust tube portion is formed in the cylindrical portion, and the communication passage and the inside of the mold are communicated or blocked on the upper surface of the head portion. A plug for use in a vent hole of a mold for molding a tire, wherein an exhaust slit is formed. The plug used for a vent hole of a mold for molding a tire according to claim 3, wherein the plug body is assembled integrally with a plug holder that fits into an exhaust tube portion of the vent hole. The exhaust slit formed on the upper surface of the head portion is used for a vent hole of a tire molding die according to claim 3 or 4 using any one of a linear shape, a spiral shape, a polygonal shape, and a circular shape. To plug. The exhaust slit formed on the upper surface of the head portion is used for a vent hole of a tire molding die according to claim 3, 4 or 5, which is formed at an inclination angle of 10 ° to 80 ° with respect to the upper surface of the head portion. To plug. The plug used for a vent hole of a tire molding die according to claim 3, 4, 5, or 6, wherein a gap between exhaust slits formed on an upper surface of the head portion is 0.5 to 1.5 mm. The plug used for a vent hole of a tire molding die according to claim 3, wherein a V groove is formed on an upper surface of a head portion of the exhaust slit. The plug used for a vent hole of a tire molding die according to claim 3, 4, 5, 6, 7 or 8, wherein the plug body and the plug holder are integrally formed of a heat resistant resin material. A tire in which a crater-shaped vent plug mark is formed on a tire surface by using a tire molding die in which a plug body is detachably attached to a large number of vent holes formed in the die.

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