JP4487128B2 - Tire molding die and plug for tire molding die - Google Patents

Description

This invention relates to a plug for tire forming mold and the tire molding die, more particularly when the tire is vulcanized, it can be molded without causing spew on tire surface, and improvement of tire finishing operations, products it relates plug for tire forming mold and the tire molding die which can improve the appearance of the tire.

  Conventionally, a tire mold used in a tire vulcanization process includes a vent hole in order to exhaust air accumulated between the mold inner surface and an unvulcanized tire to the outside of the mold during tire vulcanization molding. A large number of narrow exhaust holes, which are called, 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).

  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, deteriorating the working environment, There was a problem that it was difficult to improve the appearance of the product tire.

  In addition, a tire vulcanization mold has been proposed in which each vent hole is provided with a valve configured to close the vent hole when the tire is vulcanized and open the opening of the vent hole when the tire is released (for example, , See Patent Document 2).

However, the valve used for the vent hole of such a tire vulcanizing mold has a problem that abrasives flow into the valve when the mold is cleaned, and the valve does not operate. There was a problem that it took time and increased costs.
Japanese Utility Model No.7-33615 microfilm JP-A-9-141660

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, it is possible to improve the working environment, it is possible to improve the appearance of the product tire, it further provides a plug for a tire forming mold and the tire molding die, etc. can be easily cleaning the mold It is intended.

  In order to achieve the above object, the tire molding die according to the present invention includes a fitting recess having a step on an upper inner wall surface of an exhaust tube portion formed in a central portion in each vent hole formed in the die. A plug comprising a metal holder provided and a resin plug member fitted to the exhaust tube portion of the holder is mounted, and the plug member is attached and detached with a predetermined gap from the inner wall surface of the fitting recess. The head portion that can be fitted and a shaft portion that is integrally formed with the head portion and that has an exhaust hole in the center, and the holder and the head portion are located at the boundary between the head portion and the shaft portion. An exhaust passage that forms a fine slit that connects the gap between the exhaust hole and the exhaust hole and communicates with the exhaust hole from the gap between the holder and the head portion through the slit before inserting the tire into the mold. After the tire is inserted, the bottom of the fitting recess and the head are in contact It is an Abstract by being configured to close the exhaust passage Te.

  Further, another tire molding die of the present invention includes a metal holder provided with a fitting recess having a step on the upper inner wall surface of the exhaust tube portion formed in the center portion in each vent hole formed in the die, and A head portion that is fitted with a plug made of a resin plug member that fits into the exhaust tube portion of the holder, and the plug member is detachably fitted to the inner wall surface of the fitting recess with a predetermined gap. And a shaft portion having an exhaust hole in the center formed integrally with the head portion, and a gap between the holder and the head portion and the exhaust hole at a boundary portion between the head portion and the shaft portion. Before the tire is inserted into the mold, an exhaust passage communicating with the exhaust hole from the gap between the holder and the head portion through the through hole is formed. Is configured to close the exhaust passage by contacting the bottom surface of the fitting recess and the head portion. It is an gist and.

  Here, an inclined surface continuous with the step is formed on the lower inner wall surface of the fitting recess of the metal holder, and a gap between the fitting recess of the metal holder and the head portion of the plug member is formed. The vertical gap or the inclined gap inclined outward with respect to the bottom surface of the fitting recess.

  Also, the tire molding die plug of the present invention comprises a cylindrical metal holder that is detachably mounted in a vent hole formed in the die and a resin plug member fitted to the holder. In the tire molding die plug, the metal holder forms a fitting recess having a step on the inner wall surface of the upper opening of the exhaust tube portion formed in the center portion, and the exhaust tube portion. A locking projection is formed on the lower inner wall surface, and the plug member includes a head portion that engages the fitting recess with a predetermined gap, and an exhaust hole that communicates with the exhaust tube portion at the center. And a slit that connects the gap between the holder and the head portion and the exhaust hole at a boundary portion between the head portion and the shaft portion, or a shaft portion formed integrally with the head portion. The gist is that the through hole is formed.

Here, an inclined surface continuous with the step is formed on the lower inner wall surface of the fitting recess of the metal holder, and a gap between the fitting recess of the metal holder and the head portion of the plug member is formed. The vertical gap or the inclined gap inclined outward with respect to the bottom surface of the fitting recess.
Furthermore, the resin plug member is integrally formed of a heat resistant resin material.

Further, the tire molding die has a smooth surface by a die in which a metal holder and a plug made of a resin fitted to the holder are attached to a number of vent holes formed in the die. It is possible to produce a tire by molding .

  As described above, each vent hole formed in the mold is fitted with a metal holder having a fitting recess having a step on the upper inner wall surface of the exhaust tube portion formed in the center portion, and the exhaust tube portion of the holder. A plug made of a resin plug member to be fitted is mounted, and the plug member is detachably fitted with an inner wall surface of the fitting recess with a predetermined gap, and the head portion is integrated with the head portion. Consists of a shaft part with an exhaust hole formed in the center, and a fine slit is formed at the boundary between the head part and the shaft part to connect the gap between the holder and the head part and the exhaust hole. Before inserting the tire into the mold, an exhaust passage communicating with the exhaust hole from the gap between the holder and the head portion through the slit is formed. After inserting the tire, the bottom surface of the fitting recess and the head It is configured to close the exhaust passage by contacting the part, or to the mold In each vent hole, a metal holder provided with a fitting recess having a step on the upper inner wall surface of the exhaust tube portion formed in the center portion, and a resin plug member fitted to the exhaust tube portion of the holder, The plug member includes a head portion that is detachably fitted with an inner wall surface of the fitting recess and a predetermined gap, and an exhaust hole formed integrally with the head portion. A through hole that connects the gap between the holder and the head portion and the exhaust hole at the boundary between the head portion and the shaft portion, and the tire into the mold Before insertion, an exhaust passage that communicates with the exhaust hole from the gap between the holder and the head portion through the through hole is formed. After the tire is inserted, the bottom surface of the fitting recess and the head portion come into contact with each other and the exhaust passage Is closed so that the tire surface is spewed during tire vulcanization molding. Can be molded without causing, can skip spew removal operation of the tire finishing work, making it possible to improve the working environment, it is possible to improve the appearance of the product tire.

Since the present invention is configured as described above, the following excellent effects can be obtained. (a) During tire vulcanization molding, molding can be performed without generating spew on the tire surface.
(b) The spew removal work of the tire finishing process can be omitted.
(c) The work environment can be improved because there is little spew scrap.
(d) It is possible to reduce the cost of materials.
(e) The appearance of the product tire can be improved.
(f) When the mold is cleaned, since the bottom surface of the plug composed of the holder and the plug member is opened, no abrasive is deposited in the plug.
(g) The mold can be efficiently cleaned in a short time, and the cost can be reduced.

  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 in which a plug is attached to a vent hole formed in a die embodying the present invention, where 1 is a tire molding die and 2 is a tire vulcanization molding. A vent hole 3 formed in the mold 1 for exhausting the air accumulated between the mold 1 and the tire W, 3 is a metal holder 4 mounted on the vent hole 2, and a resin plug member 5. A plug consisting of is shown.

  In this embodiment, each vent hole 2 formed in the mold 1 is formed with a through-hole 2a that has a small diameter from the inner surface 1a of the mold 1 toward the outside. In the through-hole 2a, as shown in FIGS. 1 and 2, a cylindrical holder 4 integrally formed of a heat-resistant metal material such as stainless steel or aluminum alloy, and an exhaust tube portion 4a of the holder 4 A plug 3 composed of a plug member 5 integrally formed with a heat-resistant resin material (for example, polytetrafluoroethylene) fitted in is attached in a detachable manner.

  The metal holder 4 forms a fitting recess 6 provided with a step 4b on the inner wall surface of the upper opening of the exhaust tube portion 4a formed at the center, and the step on the lower inner wall surface of the fitting recess 6 An inclined surface 4c continuous to 4b is formed, and an annular locking projection 4d protruding inward is formed on the lower inner wall surface of the exhaust tube portion 4a.

  The plug member 5 includes a head portion 5a having a disk shape (for example, a diameter of 1.0 mm to 2.0 mm) having a predetermined thickness that is detachably fitted to the inner wall surface of the fitting recess 6 with a predetermined gap h. The shaft portion 5b is formed integrally with the head portion 5a and is provided with a shaft portion 5b having an exhaust hole 7 in the center. The boundary portion X between the head portion 5a and the shaft portion 5b has a holder 4 and a head portion 5a. A fine slit 8 (for example, 0.01 mm to 0.010) for connecting the gap h between the two and the exhaust hole 7 is formed.

  Further, the gap h is formed in a gap (for example, 0.1 mm to 0.3 mm) so that rubber Q does not flow though air Q flows during tire vulcanization, and before the tire W is inserted into the mold 1, 4 and the head portion 5a, an exhaust passage communicating with the exhaust hole 7 through the slit 8 is formed from the gap h, whereby the air Q in the mold 1 passes through the gap h to the outside of the mold. Exhausted.

  Further, after the tire W is inserted into the mold 1, the bottom surface 6a of the fitting recess 6 and the bottom surface of the head portion 5a come into contact with each other by the pressing force of the tire W to close the exhaust passage. 4 can be prevented from flowing into the exhaust cylinder portion 4a. The thickness t of the head portion 5a is preferably set to be equal to or less than the depth H of the fitting recess 6 (for example, 0.3 mm to 0.5 mm, preferably 0.4 mm). It is preferable that the head portion 5a is elastically deformed and the bottom surface of the head portion 5a is in close contact with the bottom surface 6a of the fitting recess 6 to close the exhaust passage when the tire W is inserted.

  Further, the gap h between the fitting recess 6 of the metal holder 4 and the head portion 5a of the plug member 5 has a predetermined angle α (for example, with respect to the bottom surface 6a of the fitting recess 6 as shown in FIG. 20 ° to 300 °) An inclined gap formed so as to incline outward, or a vertical gap with respect to the bottom surface 6a of the fitting recess 6 as shown in FIG.

  Next, FIGS. 4 to 6 show a second embodiment of the tire molding die 1 and the plug 3 according to the present invention. This embodiment has a holder X at the boundary portion X between the head portion 5a and the shaft portion 5b. 4 and a through hole 9 having a predetermined size (for example, a diameter of 0.1 mm or less) that connects the exhaust hole 7 and the gap h between the head 4 and the head portion 5a. Before the tire W is inserted into the mold 1, an exhaust passage communicating with the exhaust hole 7 through the through hole 9 from the gap h between the holder 4 and the head portion 5 a is formed. The air Q is exhausted to the outside of the mold through the gap h. Further, after the tire W is inserted into the mold 1, the bottom surface 6a of the fitting recess 6 and the bottom surface of the head portion 5a come into contact with each other by the pressing force of the tire W to close the exhaust passage. 4 can be prevented from flowing into the exhaust cylinder portion 4a.

  Since other configurations and operations are the same as those in the first embodiment, the same reference numerals are given and description thereof is omitted.

  7 to 9 show a third embodiment of the tire molding die 1 and the plug 3 according to the present invention. In this embodiment, the shape of the fitting concave portion 6x of the metal holder 4 is conical concave. The exhaust tube portion 4x is formed at the center thereof, and an annular locking projection 4y protruding inward is formed on the lower inner wall surface of the exhaust tube portion 4x.

  Further, the shape of the head portion 5x of the plug member 5 is formed in a conical shape that fits into the conical concave fitting recess 6x, and in the vicinity of the boundary with the shaft portion 5y, the holder 4 and the head portion. A through hole 9x having a predetermined size (for example, a diameter of 0.1 mm or less) is formed to connect the gap h between 5x and the exhaust hole 7x. Similarly to the second embodiment, before the tire W is inserted into the mold 1, the exhaust gas communicating with the exhaust hole 7x from the gap h between the holder 4 and the head portion 5x through the through hole 9x. A passage is formed so that the air Q in the mold 1 is exhausted to the outside of the mold through the gap h.

  Further, after the tire is inserted into the mold 1, the outer peripheral surface of the head portion 5x formed in a conical shape is brought into elastic contact with the inner wall surface of the conical concave fitting recess 6x to close the exhaust passage. The rubber material can be prevented from flowing into the exhaust tube portion 4x of the holder 4.

  Since other configurations and operations are the same as those in the second embodiment, the same reference numerals are given and description thereof is omitted.

  By configuring as described above, it is possible to form without generating spew on the tire surface at the time of tire vulcanization molding, to eliminate the spew removal work of the tire finishing process work, and to improve the work environment, The appearance of the tire can be improved.

Therefore, when the tire is manufactured using the tire molding die as described above, there is no spew, and the tire side portion Wx has a slight convex portion S as illustrated in FIG. A tire having a smooth appearance and good appearance can be produced.

It is a partial expanded sectional view of the tire shaping die which attached the plug to the vent hole formed in the metallic mold of this invention. It is a principal part expanded sectional view which shows the relationship between the holder and tire plug member before tire insertion. It is a principal part expanded sectional view which shows the relationship between the holder and tire plug member after tire insertion. It is a partial expanded sectional view of the tire shaping die which attached the plug to the vent hole formed in the metal mold | die which shows 2nd Embodiment of this invention. It is a principal part expanded sectional view which shows the relationship between the holder and tire plug member before tire insertion. It is a principal part expanded sectional view which shows the relationship between the holder and tire plug member after tire insertion. It is a partial expanded sectional view of the tire shaping die which attached the plug to the vent hole formed in the metal mold | die which shows 2nd Embodiment of this invention. It is a principal part expanded sectional view which shows the relationship between the holder and tire plug member before tire insertion. It is a principal part expanded sectional view which shows the relationship between the holder and tire plug member after tire insertion. It is a partial perspective view of the tire manufactured with the tire shaping die of this invention.

W Tire 1 Mold 1a Mold inner surface 2 Vent hole 2a Through-hole 3 Plug 4 Holder 4a Exhaust cylinder 4b Step 4c Inclined surface 4d Locking projection 4x Exhaust cylinder 4y Projection 5 Plug member 5a Head 5b Shaft 6 Fitting recess 6a Bottom surface 7 Exhaust hole 6x Fitting recess 7x Exhaust hole 8 Slit 9 Through hole 9x Through hole X Boundary area h Gap Q Air t Head part thickness H Fitting recess depth α Angle

Claims (8)

In a tire molding die provided with a number of vent holes for exhausting air accumulated between the die and the tire during tire vulcanization molding,
A metal holder provided with a fitting recess having a step on the upper inner wall surface of the exhaust tube portion formed in the center portion in each vent hole formed in the mold, and a resin fitted to the exhaust tube portion of the holder The plug member is made of a plug member made of metal, and the plug member is detachably fitted to the inner wall surface of the fitting recess with a predetermined gap, and a central portion formed integrally with the head portion. And forming a fine slit connecting the gap between the holder and the head portion and the exhaust hole at the boundary between the head portion and the shaft portion, Before inserting the tire into the mold, an exhaust passage that communicates with the exhaust hole through the slit from the gap between the holder and the head portion is formed, and after inserting the tire, the bottom surface of the fitting recess and the head portion are A tire molding die configured to abut and close an exhaust passage. In a tire molding die provided with a number of vent holes for exhausting air accumulated between the die and the tire during tire vulcanization molding,
A metal holder provided with a fitting recess having a step on the upper inner wall surface of the exhaust tube portion formed in the center portion in each vent hole formed in the mold, and a resin fitted to the exhaust tube portion of the holder The plug member is made of a plug member made of metal, and the plug member is detachably fitted to the inner wall surface of the fitting recess with a predetermined gap, and a central portion formed integrally with the head portion. A through hole that connects the gap between the holder and the head portion and the exhaust hole at a boundary portion between the head portion and the shaft portion, and Before inserting the tire into the mold, an exhaust passage communicating with the exhaust hole from the gap between the holder and the head portion through the through hole is formed, and after inserting the tire, the bottom surface of the fitting recess and the head portion are connected to each other. A tire molding die configured to abut and close an exhaust passage.   The tire molding die according to claim 1 or 2, wherein an inclined surface continuous with the step is formed on a lower inner wall surface of the fitting recess of the metal holder.   The tire molding die according to claim 1, 2 or 3, wherein a gap between the fitting recess of the metal holder and the head portion of the plug member is a vertical gap with respect to the bottom surface of the fitting recess.   The tire molding according to claim 1, 2 or 3, wherein the gap between the fitting recess of the metal holder and the head portion of the plug member is an inclined gap inclined outward with respect to the bottom surface of the fitting recess. Mold. A tire mold plug comprising a cylindrical metal holder detachably mounted in a vent hole formed in a mold and a resin plug member fitted to the holder,
The metal holder forms a fitting recess with a step on the inner wall surface of the upper opening of the exhaust tube portion formed at the center, and also forms a locking protrusion on the lower inner wall surface of the exhaust tube portion. The plug member includes a head portion that engages with the fitting recess with a predetermined gap, an exhaust hole that communicates with the exhaust cylinder portion at the center, and a shaft formed integrally with the head portion. And a slit or a through hole that connects the gap between the holder and the head portion and the exhaust hole is formed at a boundary portion between the head portion and the shaft portion. Plug for mold.   The tire molding die plug according to claim 6, wherein an inclined surface continuous with the step is formed on a lower inner wall surface of the fitting recess of the metal holder.   The tire according to claim 6 or 7, wherein the gap between the fitting recess of the metal holder and the head portion of the plug member is a vertical gap or an inclined gap inclined outward with respect to the bottom surface of the fitting recess. Plug for molding dies.

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