JP2012218422A - Method for manufacturing tire vulcanizing mold - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a tire vulcanizing mold capable of easily forming a slit of an exhaust mechanism opened on a mold surface at a desired position, and to provide the tire vulcanizing mold.SOLUTION: A blade 7 with an anchor part 7a protruded at one end thereof is placed on a surface 12a of a plaster mold 12 only with the anchor part 7a buried in the plaster mold 12. The part placed on the surface 12a of the plaster mold 12 of the blade 7 is covered by a covering layer 10 made of an easily disintegrable refractory material, and to the surface 12a of the plaster mold 12 in that state, a melted metal M is poured, thereby transferring the shape of the surface 12a, and casting the mold with the blade 7 casted therein. Then, the anchor part 7a protruded from the mold surface is removed, and the covering layer 10 is removed, thereby forming the slit around the blade 7. Moreover, an exhaust hole forming member 11 is removed, thereby forming an exhaust hole communicated with the outside of a piece, and making the slit and the exhaust hole communicated.

Description

  The present invention relates to a method for manufacturing a tire vulcanization mold and a tire vulcanization mold, and more specifically, a method for manufacturing a tire vulcanization mold that can easily form a slit of an exhaust mechanism that opens on the mold surface at a desired position, and The present invention relates to a tire vulcanization mold.

  The tire vulcanization mold is provided with an exhaust mechanism that discharges air remaining between the green tire and the mold and gas generated during vulcanization to the outside of the mold. Conventionally, various exhaust mechanisms that do not generate spew have been proposed (see, for example, Patent Documents 1 and 2).

  Patent Document 1 proposes an exhaust mechanism using a laminated blade in which a thin plate is bent to overlap one end and a large gap is secured to the other end in order to ensure sufficient exhaust. The laminated blade is held by a block, and an exhaust chamber surrounded by the pocket and the block is formed by fitting the block into a concave pocket on the molding surface of the mold. Air or gas is discharged into the exhaust chamber through a minute gap at one end of the laminated blade and a large gap at the other end. However, this exhaust mechanism requires a step of forming a pocket on the tire molding surface of the cast mold, a step of manufacturing an assembly in which a laminated blade is held on a block, and a step of fitting this assembly into the pocket. There is a problem in that the number of processing steps increases and the time required for manufacturing becomes long. In addition, since an appropriate space is required to provide this exhaust mechanism, it is difficult to form a gap for discharging air or gas at a desired position.

  In invention of patent document 2, when casting the piece which comprises a mold, a molten metal is divided and shot in multiple times. In the cast piece, a fine gap due to solidification shrinkage of the molten metal is formed at the joint portion between shots, and this gap becomes an exhaust passage. However, in the present invention, since the molten metal must be shot in a plurality of times, there is a problem in that the number of processing steps is increased and the time required for manufacturing becomes long.

JP 2008-260135 A JP 2000-229322 A

  An object of the present invention is to provide a method for manufacturing a tire vulcanization mold that can easily form a slit of an exhaust mechanism that opens on the mold surface at a desired position, and a tire vulcanization mold manufactured by this manufacturing method. .

  In order to achieve the above object, the tire vulcanization mold manufacturing method of the present invention is a tire for manufacturing a mold in which a molten metal is poured onto the surface of a gypsum mold and the molten metal is solidified to transfer the surface shape of the gypsum mold. In the method for producing a vulcanization mold, a blade having an anchor projecting at one end is placed on the surface of the gypsum mold with only the anchor portion embedded in the gypsum mold, and the blade is placed on the surface of the gypsum mold. The part placed on is covered with a coating layer made of an easily disintegrating refractory material, and molten metal is poured into the surface of the gypsum mold in this state to transfer the shape of the surface of the gypsum mold. After casting the mold in which the blade is cast, the anchor portion protruding from the mold surface is removed, and the coating layer is removed to remove the anchor around the blade. Tsu DOO is formed, and characterized in that through the exhaust hole and the communication leads to the slit to the outside of the mold.

  Further, the tire vulcanization mold of the present invention is a tire vulcanization mold in which a blade is embedded without projecting on a tire molding surface and solidified molten metal. It has a slit formed by removing the coating layer made of an easily disintegrating refractory material covering the blade after mold casting, and an exhaust hole for communicating the slit with the outside of the mold. To do.

  According to the method for manufacturing a tire vulcanization mold of the present invention, a blade having an anchor projecting at one end is placed on the surface of a gypsum mold with only the anchor portion embedded in the gypsum mold. The blade can be fixed and installed in position. Then, the part of the blade placed on the surface of the gypsum mold is covered with a coating layer made of an easily disintegratable refractory material, and molten metal is poured into the surface of the gypsum mold, After casting the mold with the shape transferred and casting the blade, the anchor part protruding from the mold surface and the coating layer are removed, so a slit is formed around the blade in a simple work process it can. Then, the exhaust mechanism provided with the slit opened on the mold surface at a desired position can be constructed by communicating the formed slit with the exhaust hole communicating with the outside of the mold.

  By this manufacturing method, a coating layer made of an easily disintegrating refractory material covering the blade was formed around the blade embedded without projecting on the tire molding surface by removing it after mold casting. A tire vulcanization mold according to the present invention having a slit and an exhaust hole that allows the slit to communicate with the outside of the mold can be easily obtained.

  In the method for manufacturing a tire vulcanization mold according to the present invention, the blade is provided with a through hole, and the peripheral portion of the through hole is not covered with the coating layer, and the blade base is left exposed, Molten metal can also be poured. Thereby, even if the coating layer is removed after casting the mold, the peripheral portion of the through hole and the solidified molten metal are in close contact with each other, so that the blade is firmly fixed to the mold.

  The thickness of the coating layer is, for example, 0.02 mm to 0.10 mm. As a result, spew can be reliably prevented while securing sufficient exhaust through the slit.

  A string-shaped exhaust hole forming member made of a refractory material for casting is attached to a blade placed on the surface of the gypsum mold so as to contact the coating layer, and the mold is cast by pouring the molten metal. The exhaust hole is formed by removing the exhaust hole forming member after casting the mold by pouring molten metal into the surface of the gypsum mold in this state when the mold is exposed. You can also Thereby, the cutting process for forming an exhaust hole becomes unnecessary.

  According to this manufacturing method, a tire vulcanization mold having an exhaust hole of an arbitrary shape such as a bent exhaust hole that cannot be formed by cutting can be obtained.

  A projecting portion may be provided on a portion of the blade placed on the surface of the gypsum mold, and the exhaust hole forming member may be inserted into the projecting portion and attached to the blade. Alternatively, a notch portion may be provided in a portion of the blade placed on the surface of the gypsum mold, and the exhaust hole forming member may be fitted into the notch portion and attached to the blade. By providing such a projecting portion or a notch, the exhaust hole forming member can be easily and stably attached to the blade, so that a problem that the exhaust hole forming member is displaced due to pouring can be prevented.

It is a top view which illustrates the mold for tire vulcanization of the present invention. It is a top view which illustrates the sector of FIG. FIG. 3 is a front view of FIG. 2. It is a top view which illustrates the left half of the piece of FIG. FIG. 5 is a front view of FIG. 4. It is explanatory drawing which illustrates the process of pouring gypsum into the surface of the rubber type | mold from which the anchor part of a braid | blade protrudes. FIG. 7 is a front view illustrating the blade of FIG. 6. It is explanatory drawing which illustrates the process of pouring a molten metal on the surface of the gypsum mold which attached the exhaust-hole formation member to the braid | blade in front view. It is explanatory drawing which shows the process of FIG. 8 by planar view. FIG. 9 is an enlarged front view illustrating the blade and the exhaust hole forming member in FIG. 8. It is a front view which shows the modification of the braid | blade of FIG. It is sectional drawing which illustrates the process of removing an anchor part, a coating layer, and an exhaust hole formation member from the cast piece.

  Hereinafter, a tire vulcanization mold manufacturing method and a tire vulcanization mold according to the present invention will be described based on the embodiments shown in the drawings. C arrow, R arrow, and W arrow described in the drawings indicate a circumferential direction, a radial direction, and a width direction of a green tire that is inserted into a vulcanization mold and vulcanized.

  As illustrated in FIG. 1, a tire vulcanization mold 1 (hereinafter, “mold 1”) of the present invention is a sectional type configured by assembling a plurality of sectors 2 in a ring shape. Each sector 2 includes a plurality of pieces 3 and a back block 4 as illustrated in FIGS. 2 and 3, and is attached to the back block 4 in a state where adjacent pieces 3 are in close contact with each other. In this embodiment, four rectangular pieces 3 are fixed to one sector 2 in plan view. The inner peripheral surface of each piece 3 is a tire molding surface 5. The piece 3 is formed by solidifying a molten metal M obtained by melting a metal material such as aluminum or an aluminum alloy.

  As illustrated in FIGS. 4 and 5, a groove forming protrusion 6 that forms a tire groove is provided integrally with the piece 3 on the tire forming surface 5. Further, a blade 7 made of stainless steel or the like is cast and embedded on the tire molding surface 5 without protruding. The thickness of the blade 7 is about 0.4 mm to 1.2 mm.

  A slit 8 is provided around the blade 7. The slit 8 is formed by removing a coating layer 10 to be described later that has covered the blade 7 after casting the piece 3. The slit 8 communicates with the exhaust hole 9 leading to the outside of the piece 3 (mold 1).

  In order to prevent spewing while ensuring sufficient exhaust through the slit 8, it is preferable that the gap of the slit 8 is in the range of 0.02 mm to 0.10 mm. In FIG. 4, the gap of the slit 8 is exaggerated and enlarged.

  The exhaust hole 9 of this embodiment is formed by removing a string-like exhaust hole forming portion to be described later after casting the piece 3. The size of the exhaust hole 9 is about 1 mm to 10 mm corresponding to the outer diameter. In FIG. 4, the exhaust hole 9 is bent, but it may be a straight exhaust hole 9.

  When the green tire is vulcanized using the mold 1 assembled with the piece 3, unnecessary air and gas are discharged to the exhaust hole 9 through the slit 8, and further discharged to the outside of the mold 1 through the end face of the sector 2, etc. . In this way, it is possible to ensure appropriate exhaust during vulcanization, so that tire vulcanization failures are prevented.

  A method for manufacturing the piece 3 will be exemplified below.

  As illustrated in FIG. 6, a blade 7 having an anchor portion 7 a protruding at one end is embedded in a rubber mold 14, and only the anchor portion 7 a protrudes from the surface of the rubber mold 14. The rubber mold 14 is formed by transferring the surface shape of the master mold.

  The anchor portion 7a is provided to fix the blade 7 at a desired position when the blade 7 is placed on the surface 12a of the gypsum mold 12, and is removed from the main body portion of the blade 7 in a subsequent process. Therefore, as illustrated in FIG. 7, the anchor portion 7 a is preferably connected to the main body portion (a portion other than the anchor portion 7 a) of the blade 7 in a constricted state. In this embodiment, the anchor portion 7a has a triangular shape and is connected to the main body portion of the blade 7 at its apex.

  The surface of the blade 7 may be coated with the coating layer 10 in advance. In the drawing, the covering layer 10 is indicated by oblique lines. The blade 7 (main body part) is provided with a through hole 7b. It is preferable that the peripheral portion of the through hole 7b is not covered with the coating layer 10 and the base of the blade 7 is left exposed. Since the slit 8 is formed by removing the covering layer 10 in a later step, the thickness of the covering layer 10 is set in the range of 0.02 mm to 0.10 mm.

  The covering layer 10 is formed of an easily disintegrating refractory material that is easily dissolved in water or easily broken by impact. Examples of the easily disintegrating refractory material include solid materials containing a coating material, gypsum, and a graphite-based release material. The coating material is applied to a portion of the casting mold that contacts the molten metal and functions as a heat insulating material or a protective material for the casting mold. The components of the coating material are water, sodium silicate, vermiculite, mica and bentonite. The components of the graphite release material are graphite, n-hexane, dimethyl ether and the like.

  As illustrated in FIG. 6, gypsum P is poured into the surface of the rubber mold 14 to produce the gypsum mold 12 illustrated in FIG. 8 in which the surface shape of the rubber mold 14 is transferred. The groove 12 b of the plaster mold 12 is a portion corresponding to the groove forming protrusion 6 of the mold 1. Only the anchor portion 7a is embedded in the gypsum mold 12 thus manufactured. The main body portion of the blade 7 is placed without being embedded, that is, the main body portion of the blade 7 is exposed from the surface 12 a of the gypsum mold 12.

  Next, the molten metal M is poured into the surface of the gypsum mold 12 to cast the mold 1. At that time, as illustrated in FIGS. 8 and 9, a string-like exhaust hole forming member 11 made of a cast refractory material is placed on the main body portion of the blade 7 placed on the surface 12 a of the gypsum mold 12. It attaches so that the coating layer 10 may be contacted. At this time, when the mold 1 is cast by extending the end of the exhaust hole forming member 11 until it contacts the mold 13 and casting the molten metal M, a part of the exhaust hole forming member 11 is exposed from the mold 1. Arrange to do. Since the exhaust hole 9 is formed by removing the exhaust hole forming member 11 in a subsequent process, the thickness of the exhaust hole forming member 11 is set to about 1 mm to 10 mm corresponding to the outer diameter.

  As illustrated in FIG. 10, a projecting portion 7 c is provided on a portion (main body portion) of the blade 7 placed on the surface 12 a of the gypsum mold 12, and the exhaust hole forming member 11 is pierced into the projecting portion 7 c. 7 can also be attached. Alternatively, as illustrated in FIG. 11, a notch portion 7d is provided in a portion (main body portion) placed on the surface 12a of the plaster mold 12 of the blade 7, and the exhaust hole forming member 11 is fitted into the notch portion 7d. It can also be attached to the blade 7 together. By providing the protrusion 7c and the notch 7d as described above, the exhaust hole forming member 11 can be easily and stably attached to the blade 7, so that the problem that the exhaust hole forming member 11 is displaced due to pouring is prevented. can do.

  The exhaust hole forming member 11 is formed of a refractory material for casting. The refractory material for casting is installed in a portion in contact with the molten metal such as an aluminum melting furnace and a casting frame surface, and functions to prevent erosion wear due to the molten aluminum. Examples of the refractory material for casting include a mold seal and a heat insulating material for casting.

  The main components of the mold seal are kaolin, bentonite, talc and mineral oil. The main components of the heat insulating material for casting are alumina and silica. The mold seal is flexible and can be easily transformed into any shape. Therefore, by using a mold seal as the exhaust hole forming member 11, the exhaust holes 9 having an arbitrary shape such as a bent exhaust hole that cannot be formed by cutting can be formed.

  The molten metal M is poured into the surface 12a of the gypsum mold 12 in this state, and the molten metal M is solidified to cast the piece 3 to which the shape of the surface 12a of the gypsum mold 12 is transferred. Only the anchor portion 7 a of the blade 7 protrudes from the cast piece 3, and the main body portion is embedded on the surface of the piece 3 without protruding. The main body of the blade 7 is in a state of being embedded in the piece 3 while being covered with the covering layer 10. A part of the exhaust hole forming member 11 is exposed from the end surface of the piece 3.

  Next, as illustrated in FIG. 12, the anchor portion 7 a protruding from the surface of the cast piece 3 is removed. The anchor portion 7a is removed by hand work using a direct hand or by using a tool such as a cutting device or a grinding device. By removing the anchor portion 7 a, the upper end of the blade 7 becomes the same level as the surface of the piece 3.

  Further, the covering layer 10 and the exhaust hole forming member 11 embedded in the piece 3 are removed. For example, the coating layer 10 and the exhaust hole forming member 11 are removed by spraying the high pressure water flow ejected from the spray nozzle 15 onto the coating layer 10 and the exhaust hole forming member 11. A portion where the covering layer 10 is removed becomes the slit 8, and a portion where the exhaust hole forming member 11 is removed becomes the exhaust hole 9. Since a part of the exhaust hole forming member 11 is exposed from the end face of the piece 3, the formed exhaust hole 9 communicates with the outside of the piece 3. Further, since the exhaust hole forming member 11 is in contact with the coating layer 10, the slit 8 and the exhaust hole 9 communicate with each other.

  As described above, the slit 8 that opens to the surface of the piece 3 is simply formed by the casting process in which the molten metal M is poured into the surface 12a of the gypsum mold 12 and solidified, and the anchor part 7a and the covering layer 10 are removed. be able to.

  Moreover, in the present invention, the blade 7 can be placed and fixed at a desired position on the surface 12 a of the gypsum mold 12 by the anchor portion 7 a provided at one end of the blade 7. Accordingly, the slit 8 can be formed at a desired position on the surface of the piece 3.

  For example, when part 3 of the blade 7 is simply embedded in the gypsum mold 12, the blade 7 is projected from the surface 12 a of the gypsum mold 12, and the piece 3 is cast by pouring the molten metal M, the surface of the piece 3 A part of the blade 7 protrudes. Therefore, when the tire is vulcanized using this piece 3, an unintended recess is formed on the surface of the tire due to the protruding portion of the blade 7. Therefore, in order not to form an unintended recess in the vulcanized tire, it is necessary to place the blade 7 on the surface 12 a of the gypsum mold 12 without being embedded in the gypsum mold 12. However, the blade 7 cannot be fixed at a desired position only by being placed on the surface 12a of the plaster mold 12.

  In the present invention, such a problem is solved by providing an anchor portion 7a to be removed in a later process at one end of the blade 7.

  Furthermore, in this embodiment, the exhaust hole 9 can be easily formed by the casting process and the removal process of the exhaust hole forming member 11. Therefore, after the piece 3 is cast, a cutting process for forming the exhaust hole 9 becomes unnecessary.

  Without attaching the exhaust hole forming member 11 to the blade 7, the piece 3 can be cast by pouring the molten metal M into the surface 12 a of the gypsum mold 12. In this case, the slit 8 is formed by removing the coating layer 10 after casting the piece 3, but the exhaust hole 9 needs to be formed separately. Therefore, by cutting the piece 3, an exhaust hole 9 communicating with the slit 8 and communicating with the outside of the piece 3 is formed.

  In the illustrated embodiment, the piece 3 is cast by pouring the molten metal M while leaving the base of the blade 7 exposed in the peripheral portion of the through hole 7b. Therefore, even if the coating layer 10 is removed after the casting of the piece 3, the peripheral portion of the through-hole 7b and the solidified molten metal M are in close contact with each other, so that the blade 7 is firmly fixed to the piece 3 and difficult to come off. Become.

DESCRIPTION OF SYMBOLS 1 Mold 2 Sector 3 Piece 4 Back block 5 Tire shaping | molding surface 6 Groove shaping | molding protrusion 7 Blade 7a Anchor part 7b Through-hole 7c Projection part 7d Notch part 8 Slit 9 Exhaust hole 10 Covering layer 11 Exhaust hole formation member 12 Gypsum mold 12a Surface 12b Groove 13 Mold 14 Rubber mold 15 Injection nozzle M Molten metal P Gypsum

The present invention relates to a method of manufacturing a tire vulcanizing mold, more particularly, to a method for manufacturing a tire vulcanizing mold can be easily formed at a desired position a slit exhaust mechanism that opens the mold surface.

The objective of this invention is providing the manufacturing method of the mold for tire vulcanization which can form easily the slit of the exhaust mechanism opened on the mold surface in a desired position.

It is a top view which illustrates the mold for tire vulcanization manufactured by the present invention. It is a top view which illustrates the sector of FIG. FIG. 3 is a front view of FIG. 2. It is a top view which illustrates the left half of the piece of FIG. FIG. 5 is a front view of FIG. 4. It is explanatory drawing which illustrates the process of pouring gypsum into the surface of the rubber type | mold from which the anchor part of a braid | blade protrudes. FIG. 7 is a front view illustrating the blade of FIG. 6. It is explanatory drawing which illustrates the process of pouring a molten metal on the surface of the gypsum mold which attached the exhaust-hole formation member to the braid | blade in front view. It is explanatory drawing which shows the process of FIG. 8 by planar view. FIG. 9 is an enlarged front view illustrating the blade and the exhaust hole forming member in FIG. 8. It is a front view which shows the modification of the braid | blade of FIG. It is sectional drawing which illustrates the process of removing an anchor part, a coating layer, and an exhaust hole formation member from the cast piece.

Hereinafter, the manufacturing method of the tire vulcanization mold of the present invention and the tire vulcanization mold manufactured by this manufacturing method will be described based on the embodiments shown in the drawings. C arrow, R arrow, and W arrow described in the drawings indicate a circumferential direction, a radial direction, and a width direction of a green tire that is inserted into a vulcanization mold and vulcanized.

As illustrated in FIG. 1, a tire vulcanization mold 1 (hereinafter referred to as a mold 1) manufactured according to the present invention is a sectional type configured by assembling a plurality of sectors 2 in a ring shape. Each sector 2 includes a plurality of pieces 3 and a back block 4 as illustrated in FIGS. 2 and 3, and is attached to the back block 4 in a state where adjacent pieces 3 are in close contact with each other. In this embodiment, four rectangular pieces 3 are fixed to one sector 2 in plan view. The inner peripheral surface of each piece 3 is a tire molding surface 5. The piece 3 is formed by solidifying a molten metal M obtained by melting a metal material such as aluminum or an aluminum alloy.

Claims (8)

  In a method for manufacturing a tire vulcanization mold in which a molten metal is poured onto the surface of a gypsum mold and a mold in which the surface shape of the gypsum mold is transferred by solidifying the molten metal, a blade having an anchor projecting at one end is provided. Then, only the anchor part is embedded in the plaster mold and placed on the surface of the plaster mold, and the part of the blade placed on the surface of the plaster mold is covered with a coating layer made of an easily disintegrating fireproof material. In the coated state, the molten metal is poured into the surface of the gypsum mold in this state, the shape of the surface of the gypsum mold is transferred, the mold in which the blade is cast is cast, and then the anchor protruding from the mold surface A slit is formed around the blade by removing the cover and removing the coating layer, and this slit communicates with an exhaust hole that communicates with the outside of the mold. Method for producing a tire vulcanizing mold for causing.   2. The tire vulcanization according to claim 1, wherein the blade is provided with a through-hole, and the peripheral portion of the through-hole is not covered with the coating layer, and the base of the blade is left exposed, and the molten metal is poured. Method for manufacturing mold.   The method for manufacturing a tire vulcanization mold according to claim 1 or 2, wherein the thickness of the coating layer is 0.02 mm to 0.10 mm.   A string-shaped exhaust hole forming member made of a refractory material for casting is attached to a blade placed on the surface of the gypsum mold so as to contact the coating layer, and the mold is cast by pouring the molten metal. The exhaust hole is formed by removing the exhaust hole forming member after casting the mold by pouring molten metal into the surface of the gypsum mold in this state when the mold is exposed. The manufacturing method of the mold for tire vulcanization in any one of Claims 1-3 to do.   The projecting part is provided in the part mounted on the surface of the plaster mold of the blade, and the exhaust hole forming member is inserted into the projecting part and attached to the blade. Manufacturing method for tire vulcanization mold.   The blade according to any one of claims 1 to 4, wherein a notch portion is provided in a portion of the blade placed on the surface of the plaster mold, and the exhaust hole forming member is fitted into the notch portion and attached to the blade. The manufacturing method of the mold for tire vulcanization | cure of description.   In a tire vulcanization mold manufactured by embedding a blade without projecting on a tire molding surface and solidifying molten metal, the blade is surrounded by an easily disintegrating refractory material covering the blade. A tire vulcanization mold comprising: a slit formed by removing the coating layer to be formed after mold casting; and an exhaust hole for communicating the slit with the outside of the mold.   The tire vulcanization according to claim 7, wherein the exhaust hole is formed by removing a string-like exhaust hole forming member made of a refractory material for casting cast into the molten metal after mold casting. Mold.

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