JP2003211454A - Method for manufacturing tire mold - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a tire mold capable of simply and efficiently reducing the cost of the tire mold wherein a non-fundamental shape is added to the surface fundamental shape of a tire (a part of the fundamental shape is deformed into the non-fundamental shape) at formation of a tire whole casting mold. <P>SOLUTION: A plurality of fundamental partial casting molds 20 having as the surface fundamental shape of the tire are formed and recessed parts 7 are formed to a plurality of the fundamental partial casting molds 20 and a reversal member 3 having a surface shape different from the fundamental shape is allowed to approach each of the recessed parts 7 of the fundamental partial casting molds 20 to form a gap between each of the recessed parts 7 of the fundamental partial casting molds 20 and the surface having the reversal shape of the non-fundamental shape of the reversal member 3. An uncured casting mold material 4 is charged in the gap to be cured and at least a part of the surface shape of each of the fundamental partial casting molds is formed into the non-fundamental shape from the fundamental shape to form a non- fundamental partial casting mold having the non-fundamental shape as its surface shape. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for manufacturing a tire molding die. More specifically, in a method for manufacturing a tire molding die using a precision casting method, when a partial mold is combined to form an entire mold, the shape (basic shape) forming a part of the surface shape of the tire is not changed. A tire capable of easily and efficiently manufacturing a mold for molding a tire having a shape to which a basic shape is added (a part of the basic shape is transformed to a non-basic shape) as a surface shape at low cost The present invention relates to a method for manufacturing a molding die.

[0002]

2. Description of the Related Art A tire-molding die has a complicated shape because the tire design (surface shape) has a large number of sharp corners and thin projections called blades. Often manufactured by casting suitable for forming.

A tire molding die produced by such casting is usually divided into partial dies, and these partial dies are wholly combined and used as a whole die at the time of tire molding. As a method of dividing such a mold, cutting along the circumference in the direction of the central axis is performed 7 to 11
Method of dividing into about several partial dies (upper and lower integrated type), and cutting in the direction perpendicular to the central axis (tire radial direction)
There is a method of dividing into individual partial dies (upper and lower halves),
It can be appropriately selected according to manufacturing conditions and the like.

Further, such a partial mold has a basic shape (pitch design) having a size obtained by dividing the partial mold into several tens in the circumferential direction in order to prevent noise generation due to resonance of the design during tire running. ) Is enlarged and reduced to multiple types of width dimensions such as S, M, and L, and a prototype (master model) having a reduced shape is produced, and these are randomly combined to form a 360 ° design, but the manufacturing cost is reduced. In order to create the original mold (master model) with only the minimum necessary design, create the required number of partial molds through rubber mold inversion, and assemble this to form the whole mold for one ring. This may be used to manufacture a tire molding die.

For example, as shown in FIG. 16, when a method of dividing into upper and lower parts is used, in the conventional method of manufacturing a tire molding die, a desired tire shape is basically divided into several parts in the circumferential direction. A master model 101 having a shape is formed (FIG. 16A), and a rubber mold 102 having an inverted shape of the master model 101 is formed (FIG. 16B).
02, the basic partial mold 103 which is the inverted shape
Are formed in the required number (Fig. 16 (c)), and each basic partial mold 1
03 is dried (fired), and the end face is cut so that it can be assembled (FIG. 16).
(D)), 1 by assembling each basic partial mold 103
A ring-shaped whole mold 104 is formed (FIG. 16).
(E)). The whole mold 104 formed in this way
Is placed on a surface plate 108, surrounded by a casting mold 105, and a molten alloy 106 is poured into a gap between the entire mold 104 and the casting mold 105 (FIG. 16 (f)), and the molten alloy 106 is hardened. The tire molding die 107 having a reverse shape of the tire shape was manufactured (FIGS. 16G and 16H).

In the manufacturing method configured as described above, the size of the master model is usually determined based on the basic shape (pitch design).
That is, the master model having the most efficient size is manufactured by balancing the number of steps of manufacturing the master model and the number of steps related to repeating and assembling the partial mold. For example, the minimum master model required to manufacture a tire mold having a total of 54 pitches of 16 S pitches, 23 M pitches and 15 L pitches in three types of pitch variations of S, M and L is , S, M
And one for each L pitch, but with this, from the rubber mold reversely created from each master model, 16 at S pitch
It is necessary to invert the partial molds, 23 at the M pitch, and 15 at the L pitch, and in the process of assembling the partial molds, a total of 54 partial molds must be assembled. Will result in a deterioration in efficiency. Conversely, the master model is 5
When it comes to making all the four partial molds,
This leads to a deterioration in the efficiency of the master model manufacturing process.

In addition, a part of the tire design may be required to have a shape (non-basic shape) different from the basic shape (pitch design), and this non-basic shape has a basic shape (pitch design). Are arranged in a different pattern. This non-basic shape is, for example, a mark indicating the position of the slip sign, the slip sign itself, a groove side surface, a design for preventing stone trapping installed on the groove bottom surface, or locally for improving the appearance quality of the tire. It is like a design to be arranged, and when trying to make a master model in consideration of these arrangements as well, the master model must be increased in size, and in some cases 360
° A master model for the entire circumference must be produced.

Therefore, conventionally, in order to reduce the manufacturing cost of a tire molding die, non-basic shapes such as a basic shape (pitch design) and a disposition pattern are manually formed in a mold stage. There were many But,
As the tire design has become complicated in recent years, there has been a problem that it is difficult to deal with it by hand.

Further, it is practiced to form a thin groove of about 0.1 to 0.7 mm called “sipe” on the tire. When such a thin "sipe" is formed by a casting method or the like, the strength of the "sipe" part in the casting becomes insufficient, so a thin high-strength material called "blade" (usually steel) is used. Often cast in a casting.

As shown in FIG. 17, in the conventional method for manufacturing a tire molding die, the model blade 205 is set on or attached to the master model 201 (see FIG. 17).
(A)), the rubber model 20 by reversing the master model 201
2 is formed (FIG. 17B), the sipe blade 209 is installed on the rubber mold 202 (FIG. 17C), and the rubber mold 202 is formed.
Is reversed to the partial mold 203, the sipe blade 209 is moved to the partial mold 203 (FIG. 17D), the mold 207 is formed from the partial mold 203 by casting, and the sipe blade 209 is moved to the mold 207. (FIG. 17E) to manufacture the mold. In this case, examples of the mold material that forms the partial mold 203 include gypsum, ceramics, and metal.

However, in the method for manufacturing a tire molding die by such a casting method, the sipe blade 20 which is embedded by being cut on the partial mold 203 and hung on the joint surface portion.
9 is present, the sipe blade 209 is pulled out from the partial mold 203 before cutting the end face of the partial mold 203, the partial mold 203 is cut, and after the assembly is completed, it is manually buried again. Has been adopted.

However, this sipe blade 20
When the shape of 9 is a so-called undercut shape in which the draft at the portion implanted in the partial mold 203 is reversed, this is difficult to deal with, and the surface of the partial mold 203 around the sipe blade 209 is In advance, engrave and engrave until there is no undercut shape, sipe blade 20
9 is removed, the end face of the partial mold 203 is cut and assembled, the sipe blade 209 is implanted, and then the dug portion of the partial mold 203 is refilled with the mold material, and then the surface shape is restored manually. However, there is a problem that a large number of man-hours are required.

Further, in the step of cutting the end face of the partial mold, when there are minute projections or the like as a part of the basic shape at the cutting position of the partial mold, these projections or the like are lost when the partial mold is cut. In some cases, after assembling the partial mold, there is a problem that the work of restoring the part must be manually performed.

[0014]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and in a method of manufacturing a tire molding die using a precision casting method, a partial mold is combined to form an entire mold. At the time of forming, a tire having a surface shape that is a shape (basic shape) that forms a part of the surface shape of the tire plus a non-basic shape (a part of the basic shape is transformed to a non-basic shape) It is an object of the present invention to provide a method for manufacturing a tire-molding mold, which can manufacture a mold for doing so simply and efficiently at low cost.

[0015]

Means for Solving the Problems In order to achieve the above-mentioned object, the present invention provides the following tire molding die.

[1] A plurality of partial molds having a shape which constitutes a part of the surface shape of the tire is formed as the surface shape, and the plurality of partial molds are combined so as to have the shape of the tire to form an entire mold. A method for producing a tire molding die that is a reversal type of the tire by forming and encapsulating the whole mold with a casting frame, and pouring a molten metal into the gap between the whole mold and the casting frame to cure, When forming the overall mold by combining partial molds, a plurality of basic partial molds having a shape (basic shape) forming a part of the surface shape of the tire as its surface shape are formed, and the plurality of basic partial molds are formed. Among them, at least a part of the surface of one or more of the basic partial mold is formed with a recess, and a reversing member having a surface shape obtained by reversing a non-basic shape different from the basic shape is used. A gap is formed between the concave portion of the basic partial mold and the surface of the reversing member having the non-basic reversal shape in proximity to the concave portion of the basic partial mold, and the uncured portion is uncured. A non-basic partial mold having the non-basic shape as its surface shape by transforming at least a part of the surface shape of the basic partial mold from the basic shape to the non-basic shape. And combining the basic partial mold having the basic shape as its surface shape and the non-basic partial mold having the non-basic shape as its surface shape, the non-basic shape is added to the basic shape. A method for manufacturing a tire-molding die, comprising forming the overall mold having a shape as its surface shape.

[2] The method for manufacturing a tire mold according to [1], wherein the basic partial mold is formed of a self-curing mold material.

[3] A through hole penetrating from the bottom surface of the recess formed in at least a part of the surface of one or more of the basic partial molds among the plurality of basic partial molds to the back surface of the basic partial molds. Formed, from the opening on the back side of the basic partial mold of the through hole, via the through hole,
The tire molding metal according to [1] or [2], wherein the uncured mold material is filled in a gap between the recess of the basic partial mold and the surface of the reversing member having the non-basic reversal shape. Mold manufacturing method.

[4] A solvent for softening the uncured template material is added to the uncured template material, and a hollow cylindrical body made of a material that does not allow the solvent to penetrate is provided on the rear side of the basic partial template of the through hole. Removably inserted from the opening,
The method for manufacturing a tire molding die according to [3], wherein the gap is filled with the uncured mold material containing the solvent via the hollow cylinder.

[5] After filling the gap with the uncured mold material containing the solvent through the hollow cylindrical body, the hollow cylindrical body is filled with the uncured mold material inside the hollow cylindrical body on the rear end side. The method for manufacturing a tire molding die according to the above [4], in which the uncured mold material containing the solvent is filled into the gap without any gap by pressurizing from.

[0021]

Embodiments of the present invention will be described below.
A specific description will be given with reference to the drawings.

The method for producing a tire molding die of the present invention is to form a plurality of partial molds each having a shape forming a part of the surface shape of the tire as the surface shape, To form a whole mold in combination to form a shape, the whole mold is surrounded by a casting frame, the molten metal is poured into the gap between the whole mold and the casting frame, and the mixture is cured to cure the tire, which is a reversal type of the tire. A method of manufacturing a mold, wherein a plurality of basic partial molds having a shape (basic shape) forming a part of the surface shape of the tire as the surface shape when the partial molds are combined to form the overall mold Forming a concave portion on at least a part of the surface of one or more of the basic partial molds of the plurality of basic partial molds, and inverting a non-basic shape different from the basic shape. The reversal member having the surface shape made close to the concave portion of the basic partial mold, and a gap between the concave portion of the basic partial mold and the surface having the non-basic shape reversed shape of the reversal member. Is formed, and the gap is filled with uncured template material and cured, and at least a part of the surface shape of the basic partial mold is transformed into the non-basic shape from the basic shape to the non-basic shape. Forming a non-basic partial mold having its surface shape, combining the basic partial mold having the basic shape as its surface shape, and the non-basic partial mold having the non-basic shape as its surface shape, the basic It is characterized by including forming the said whole mold which has the shape which added the said non-basic shape to the shape as its surface shape.

According to the method for manufacturing a tire molding die of the present invention, for example, as shown in FIG. 1A, the surface has a shape (basic shape) that constitutes a part of the surface shape of the tire. A required number of basic partial molds 1 are formed, and a desired portion (non-basic shape forming portion) 20 of a rib (main groove) 10 of the basic partial mold 1 as shown in FIG. A basic shape, for example, a non-basic partial mold (not shown) having a groove fence (projection) 2 locally as its surface shape with a regularity different from the basic shape as shown in FIG. Can be formed.

That is, although not shown, first, a master model having a basic shape is formed on the surface of the master model, a rubber mold which is an inverted model of the master model is formed, and the rubber mold is used to form the same shape as the master model. Basic part mold 1
(See FIG. 1A).

Next, as shown in FIG. 2A, the side shape of the rib 10 (see FIG. 1A) of the basic partial mold 1 (see FIG. 1A) and the non-basic shape to be imparted An inversion member 3 having a surface shape obtained by inverting the groove fence 2 (see FIG. 1C) is formed. It is preferable that the reversing member 3 is formed to be slightly larger than the non-basic shape to be provided. Further, examples of the material forming the reversing member 3 include resin, metal, and rubber. Of these, rubber is preferable when it has an undercut shape.

Next, as shown in FIG. 2 (b), on the surface of the basic partial mold, a portion for deforming the surface shape into a non-basic shape (in FIG. 2 (b), non-basic shape formation of the basic partial mold is formed. The reversal member 3 is temporarily placed so as to face the portion 20).

Next, as shown in FIG. 2C, the reversing member 3 (see FIG.
(See (b)) Position and groove fence 2
A position for forming (see FIG. 1C) is determined, and a marking line 8 or the like is used to make a mark.

Next, as shown in FIG. 2D, the groove fence 2 is attached to the non-basic shape forming portion 20 of the basic partial mold.
(See FIG. 1 (c)) is formed with sufficient strength,
At least a part of the surface having the basic shape of the non-basic shape forming portion 20 of the basic partial mold forming the groove fence 2 (see FIG. 1C) is excavated to form the recess 7.

Next, as shown in FIG. 2E, the reversing member 3 is arranged again in the non-basic shape forming portion 20 of the basic partial mold. In this case, in the subsequent steps, the reversal member 3 may be fixed using a weight or the like so as not to be displaced from the non-basic shape forming portion 20 of the basic partial mold.

Next, as shown in FIG. 2F, the slurry (uncured mold material) 4 is injected into the gap between the non-basic shape forming portion 20 of the basic partial mold and the reversal member 3. At this time, it is preferable to remove bubbles by tracing the surface of the slurry (uncured template material) 4 injected with a brush or the like so as not to entrap air bubbles or the like.

Next, as shown in FIG. 2G, after the slurry (uncured template material) 4 has hardened, the reversal member 3 is removed.

Next, FIG. 2H shows the hardened slurry 4
If the surplus portion 9 (see FIG. 2 (g)) protrudes from the non-basic shape forming portion 20 of the basic partial mold,
The surplus portion 9 is removed by a scraper 6 or the like, and then the shapes of the groove fence 2 and the non-basic shape forming portion 20 of the basic part mold are adjusted as necessary.

With such a configuration, as shown in FIG.
The groove fence 2 having a non-basic shape can be easily produced in the non-basic shape forming portion 20 of the basic partial mold as shown in (i), and the groove fence 2 having a non-basic shape is used as the surface shape. A basic partial mold (not shown) can be easily made. After that, although not shown, by combining the basic partial mold and the non-basic partial mold to form the whole mold, the whole mold is surrounded by a casting frame, and the molten metal is poured into the gap between the whole mold and the casting frame to be cured. It is possible to manufacture a tire molding die having a desired tire shape inverted shape.

The formation position of the concave portion 7 formed in the non-basic shape forming portion 20 of the basic partial mold may be formed so as to correspond to each groove fence, as shown in FIG. 3A. As shown in FIG. 3B, the groove fences may be formed large so that two or more adjacent groove fences can be formed at the same time.

Conventionally, when a non-basic shape is formed on the surface of a basic partial mold, it has been performed manually, but according to the present invention, a step of manufacturing a tire molding die using a precision casting method. In forming the whole mold by combining the partial molds, a part of the surface of the partial mold that has a basic shape (basic design) that constitutes a part of the tire surface shape is a non-basic shape, which is different from the basic shape. Form a whole mold by transforming into a shape and combining a basic partial mold having a basic shape on its surface with a non-basic partial mold having a non-basic shape on its surface, and forming a part of the basic shape (basic design). A mold for molding a tire deformed into a non-basic shape (predetermined design) can be manufactured easily and efficiently at low cost.

Further, in the method for manufacturing the tire molding die shown in FIG. 2, the basic part mold 1 (the non-basic shape forming part 2
0) When the slurry (uncured mold material) 4 can be poured from the surface side, that is, the reversing member 3 does not completely cover the concave portion 7 of the basic partial mold 1 (non-basic shape forming portion 20). In this case, it is particularly effective because the slurry can be poured easily.

The tire molding die manufacturing method of the present invention is the same as the manufacturing method shown in FIG. 2, except that the concave portion 7 formed on at least a part of the surface of the basic partial mold 1 (non-basic shape forming portion 20). A through hole is formed from the bottom surface of the basic mold 1 to the rear surface of the partial mold. The slurry 4 (uncured template material) may be filled in the gap with the inverted shape of the above.

For example, as shown in FIGS. 4 (a) to 4 (c), a part of the basic partial mold 11 has different positions (arranged in the circumferential direction) for each part arranged in the tire molding die. However, when it is desired to form the non-basic partial mold 16 by giving the non-basic shape 12 such as a slip sign having an R shape, which is difficult to handle by hand, the non-basic partial mold 16 can be formed as follows.

FIG. 5 is an explanatory view showing a step of forming a non-basic partial mold by giving a non-basic shape such as a slip sign to a part of the basic shape of the surface of the basic partial mold. First, although not shown, a master model having a shape obtained by dividing a tire having a desired surface shape into at least two or more parts is formed, and then a rubber mold that is an inverted shape of the master model is formed, and a rubber mold is used. Then, a plurality of basic partial molds having the same shape as the inverted master model are formed.

Next, as shown in FIG. 5A, a reversing member 13 having a reversal shape of the non-basic shape 12 (see FIG. 4A) desired to be applied is formed. At this time, the reversing member 13 is preferably formed to be slightly larger than the non-basic shape 12 (see FIG. 4A). Also,
As a material for forming the reversing member 13, for example, resin,
Metal and rubber can be mentioned. Of these, rubber is preferable when it has an undercut shape.

Next, as shown in FIG. 5B, the position where the non-basic shape 12 (see FIG. 4A) is formed on the basic partial mold 11 is determined, and the position is reversed to the region to which the non-basic shape is given. The member 13 is temporarily placed.

Next, as shown in FIG. 5C, a marking line 18 or the like is provided so that the position where the reversing member 13 is arranged can be seen again.

Next, as shown in FIG. 5D,
The reversing member 13 is removed, and a region where the predetermined shape 12 (see FIG. 4A) is provided on the surface of the basic partial mold 11 is excavated to form the recess 17. This recess 17 has a non-basic shape 1.
2 (see FIG. 4A) and smaller than the reversing member 13.

Next, as shown in FIG. 5E, a through hole 19 penetrating from the bottom surface of the concave portion 17 formed on the surface of the basic partial mold 11 to the rear surface of the basic partial mold 11 is drilled.
5 and the like. The through hole 19 has a diameter smaller than that of the bottom surface of the recess 17 of the basic partial mold 11.

Next, as shown in FIG. 5 (f), the reversing member 13 is arranged again on the basic partial mold 11. in this case,
The reversal member 13 completely covers the concave portion 17 of the basic partial mold 11.

Next, as shown in FIG. 5 (g), the reversal member 13 arranged in the basic partial mold 11 is detachably fixed so as not to be displaced, for example, by using a rubber band 15 ′ or the like. To do.

Next, as shown in FIG. 5H, the orientations of the basic partial mold 11 and the reversing member 13 are changed so that the opening of the through hole 19 on the back side of the basic partial mold 11 faces upward. The slurry (uncured mold material) 14 is poured from the opening through the through hole 19 while being careful not to entrap air bubbles or the like.

Next, as shown in FIG. 5I, after the slurry 14 is filled, the basic partial mold 11 is held in that state until the slurry 14 is hardened, and after the slurry 14 is hardened, the basic partial mold 11 is held. 11 is returned to the original position, and the reversal member 13 is removed.

Next, as shown in FIG. 5K, a non-basic shape 12 such as a slip sign formed on the surface of the basic partial mold 11 is finished by hand or the like, if necessary. In this way, the non-basic partial mold 16 is completed as shown in FIG.

Thereafter, although not shown, the basic partial mold and the non-basic partial mold are combined to form an overall mold,
The entire mold is surrounded by a casting frame, and a molten metal is poured into a gap between the entire mold and the casting frame to cure the molten metal, whereby a tire molding die having a desired tire shape inverted shape is manufactured.

With this configuration, a mold for molding a tire in which a basic shape, which is a part of the basic design, is transformed into a non-basic shape having a predetermined design can be manufactured easily and efficiently at low cost. can do.

The production method shown in FIG. 5 is preferably performed basically before the basic partial mold 11 is in a green state, that is, before initial (temporary) drying or initial (temporary) baking, but after drying and baking. It may be.

Further, according to the manufacturing method configured as described above, it can be applied to the step of cutting the partial mold, burying the sipe blade in the joint surface, and the repair work of the defective part of the partial mold. it can.

For example, as shown in FIG. 6, when the sipe blade 22 embedded in the basic partial mold 21 has an undercut shape, or when the basic partial mold 21 is cut and embedded over the joint surface 26. By using the present invention, the sipe blade 22 can be easily cut and embedded in the joining surface 26 of the basic partial mold 21, and a non-basic partial mold (not shown) can be formed.

7 (a) to 7 (j) are explanatory views showing, in the order of steps, a method for manufacturing a tire molding die according to the present invention, which corresponds to the case where the partial mold is cut and the joining surface portion is hung by the sipe blade.

First, as shown in FIG. 7A, a master model having a shape in which a tire having a desired surface shape is divided into at least two or more parts is formed, and then a rubber mold which is an inverted shape of the master model is formed. And a plurality of basic partial molds 21 having the same shape as the master model, which is the inverted shape thereof, are formed using a rubber mold. At this time, when the sipe blade 22 is present on the cutting and joining surface 26 of the basic partial mold 21, the sipe blade 22 existing in that region is present.
The basic partial template 21 is formed in the state where the above is removed.

Next, as shown in FIG. 7 (b), the region where the basic partial mold 21 is cut and the bonding surface 26 in which the sipe blade 22 is buried is excavated so as to be deeper than the buried depth of the sipe blade 22. To form the recess 27.

Next, as shown in FIG. 7C, adjacent basic partial molds 21 are assembled. This process is shown in FIG.
It may be performed before the step of excavating the basic partial mold 21 shown in FIG.

Next, as shown in FIG. 7D, the recess 2
A through hole 29 penetrating the back surface of the basic partial mold 21 from the bottom surface of 7 is formed using a drill 25 or the like. The through hole 29 has a diameter smaller than the bottom surface of the recess 27 of the basic partial mold 21.

Next, as shown in FIGS. 7D to 7E, the reversing member 23 having on its surface a reversal shape of the non-basic shape which should originally be formed in the region where the recess 27 of the basic partial mold 21 is formed. To form. The reversal member 23 can be easily formed by reversing the region where the sipe blade 22 is formed, except for the cutting and joining surface 26. Further, since the sipe blade 22 has an undercut shape, the reversing member 23 is preferably made of flexible rubber or the like.

Next, as shown in FIG. 7F, an inverted shape 22 ′ of the sipe blade formed on the inversion member 23 is formed.
The sipe blade 22 to be formed is inserted into the basic partial mold 21 (see FIG. 7A).

Next, as shown in FIG. 7G, the reversing member 23 having the sipe blade 22 inserted therein is arranged and fixed so as to cover the region in which the recess 27 of the basic partial mold 21 is formed. At this time, it can be easily fixed by using a rubber band (not shown) or the like.

Next, as shown in FIG. 7H, the position of the basic partial mold 21 is changed so that the opening of the through hole 29 on the back side of the basic partial mold 21 faces upward, and Slurry (uncured mold material) 24 is poured from the opening on the back side of the partial mold 21 through the through hole 29.

Next, as shown in FIG. 7I, after the slurry 24 is hardened, the reversing member 23 is removed. At this time, the sipe blade 22 inserted in the reversing member 23 is put together with the hardened slurry 24 in the basic partial mold 2
It is buried in 1.

Next, as shown in FIG. 7 (j), the surface of the basic partial mold 21 is finished by manual work or the like, if necessary. In this way, the non-basic partial mold 16 is completed.

Thereafter, although not shown, the basic partial mold and the non-basic partial mold are combined to form an overall mold,
The entire mold is surrounded by a casting frame, and a molten alloy is poured into a gap between the entire mold and the casting frame to cure the molten alloy, thereby manufacturing a tire molding die having a desired tire shape reversal shape.

With this configuration, the sipe blade and the like can be easily embedded in the cutting and joining surfaces of the partial mold. Further, by performing the same steps as above, it is possible to easily repair the defect of the partial mold that occurs when the mold is released from the rubber mold and the damaged portion of the basic shape that occurs when the partial mold is cut.

Further, in the above-described step shown in FIG. 7H, when the slurry 24 does not sufficiently spread inside the reversing member 23, as shown in FIG. Slurry 28 (uncured template material) is poured into the inside of the container, and as shown in FIG.
8 is hardened, and the surface thereof is roughened so that the slurry 28 hardened in the subsequent step can be easily bonded to another slurry 24 described later (see FIG. 8D). For example, it is preferable that the surface of the slurry 28 inside the reversing member 23 has an undercut shape.

Next, as shown in FIGS. 8C to 8D, the reversal member 23 is fixed to the basic partial mold 21, and the slurry 24 is passed through the opening formed on the back surface of the mold material 21. Pour into 29.

Next, as shown in FIG. 8E, after the slurry 24 is hardened, the reversing member 23 is removed. At this time, the sipe blade 22 inserted in the reversing member 23 is embedded in the basic partial mold 21 together with the hardened slurry 24 and the slurry 28.

With such a configuration, even if a reversing member having a shape in which the slurry is not sufficiently spread by simply pouring the slurry (uncured mold material) into the desired shape, Shaped molds can be formed.

Further, in the method for manufacturing a tire molding die of the present invention, a hollow cylindrical body made of a material that does not allow a solvent to permeate the slurry (uncured mold material) to penetrate is inserted into the through hole described above. It is preferable to fill the slurry (uncured template material) via the hollow cylinder.

The method for manufacturing a tire molding die having such a configuration is performed by, for example, performing the step of filling the slurry (uncured mold material) shown in FIGS.
It can be realized by changing the steps shown in (a) to (f).

First, as shown in FIG. 9A, the basic partial mold 11 and the reversing member 13 are placed at positions such that the opening formed on the back side of the basic partial mold 11 of the through hole 19 is on the upper side. Rotate to.

Next, as shown in FIG. 9B, the slurry 14 is placed in the through hole 19 formed in the basic partial mold 11.
Hollow cylindrical body 3 made of a material that does not allow a solvent for softening (see FIG. 5 (h)) to penetrate, for example, resin or metal.
Insert 5.

Next, as shown in FIG. 9C, the hollow cylindrical body 35 is inserted up to the immediate vicinity of the reversing member 13, and the slurry 14 is passed through the hollow cylindrical body 35 and the basic partial template 11 and the reversing member 13 are inserted. Pour into the gap between. At this time, the slurry 14 can be easily poured into the hollow cylindrical body 35 by using the funnel 37 or the like.

Next, as shown in FIG. 9D, after the slurry 14 is filled in the hollow cylindrical body 35, the slurry 1
4 through the hollow cylindrical body 35 until just before starting to cure.
Leave at 9. At this time, it is preferable to give a slight vibration to the hollow cylindrical body 35 so that the slurry 14 spreads over the gap between the basic partial mold 11 and the reversing member 13.

Next, as shown in FIGS. 9E to 9F, the hollow cylindrical body 35 is removed from the basic partial mold 11 immediately before the slurry 14 is cured. At this time, the hollow cylindrical body 35 is gently extracted while being slightly vibrated.
It is preferable that the slurry 14 (uncured template material) does not remain inside. The subsequent steps are the same as the steps after FIG. 5 (i).

With this configuration, the fluidity of the slurry (uncured template material) can be ensured until the filling is completed, and the slurry (uncured template material) can be easily filled. . Further, even through holes having a small diameter can be filled through the hollow cylindrical body, and the amount of slurry (uncured template material) can be reduced.

Further, in the method for manufacturing a tire molding die of the present invention, since the slurry is filled into the gap without any gap, after the slurry (uncured mold material) is filled into the gap via the hollow cylindrical body. It is preferable to pressurize the hollow cylinder from the rear end side of the partial mold.

For example, as shown in FIG. 10A, the hollow cylindrical body 3 is formed in the through hole 19 formed in the basic partial mold 11.
5 is inserted and the basic partial mold 1 is passed through the hollow cylindrical body 35.
After the slurry (uncured template material) 14 is filled in the gap between 1 and the reversal member 13, the slurry 14 (uncured template material) is filled with a cylinder 36 or the like as shown in FIG. By pressing the inside of the hollow cylindrical body 35 until just before the curing is started, the slurry (uncured mold material) 14 can be filled into the gap between the basic partial mold 11 and the reversing member 13 without any gap. In this case, the applied pressure is
It is preferable that the reversing member 13 does not come off from the basic partial mold 11 and the deformation that deviates from the dimensional tolerance is not given to the reversing member 13. Specifically, 0.1
It is preferably about MPa to 5 MPa.

Further, as shown in FIG. 10 (c), by using a long hollow cylindrical body 35, the slurry 14
The pressure (head pressure) generated by the self-weight of the above may be used. With this head pressure, the height of the portion where the hollow cylindrical body 35 is filled with the slurry 14 is set to H, and the basic partial mold 11
When the height of the slurry 14 in the portion filled therein is h, the pressure corresponds to the height of H−h.

With such a configuration, the slurry 14 sufficiently spreads in the gap between the basic partial mold 11 and the reversing member 13, and the non-basic shape of the reversing member 13 is formed on the basic partial mold with higher accuracy. Can be a non-basic partial template.

When the slurry 14 is pressurized, the slurry 14 may leak from the gap between the hollow cylindrical body 35 and the through hole 19, but the diameter of the through hole 19 and the diameter of the hollow cylindrical body 35 Hollow cylinders 3
A small amount of the slurry 14 leaked from the through hole 5 into the through hole 19 promptly absorbs the solvent into the basic partial mold 11 to lower the fluidity, and the slurry itself acts as a sealing material.
Further leakage of the slurry 14 can be prevented.

[0085]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples.

Example 1 A basic partial mold 1 having only a basic shape formed on the surface thereof, as shown in FIGS. 11 (a) and 11 (b), was used for the tire molding die of the present invention shown in FIG. Using the manufacturing method, FIG.
A groove fence as shown in (c) to (e) was formed. FIG. 11A is a perspective view of a basic partial mold in which only the basic shape is formed on the surface, FIG. 11B is a partially enlarged view of FIG. 11A, and FIG. 11C is a non-basic partial mold in which a groove fence is formed. 3 is a partially enlarged view of FIG. 3, (d) is a side view of (c), and (e) is a plan view of (c). The basic partial mold 1 has a height of 140
mm, the outer circumference is R516, and the surface has two ribs 10 (main grooves) having a width of 12 mm and a depth of 15 mm. By combining 15 of these basic partial molds 1, a tire molding die can be formed in an inverted shape. Form a whole mold. In this embodiment, the groove fence 2 having a non-basic shape is arranged on the surface of the whole mold at an arrangement cycle different from that of the basic shape.
It was arranged in the place. Basic partial mold 1 and slurry 4 (Fig. 2
As the reference), non-foamed gypsum (trade name: G-6 manufactured by Noritake Co., Ltd.) was used. The compounding conditions for forming the basic partial mold 1 are: non-foamed gypsum: water = 1
00:60 (weight ratio), and the mixing condition for forming the slurry is non-foamed gypsum: water = 100: 80 (weight ratio).
And Further, as the material of the reversing member 3 (see FIG. 2), silicone rubber (trade name: TSE350 manufactured by Toshiba Silicone Co., Ltd.) was used.

As shown in FIG. 11E, the cross-sectional shape of the groove fence 2 formed in this example has an upper bottom of 2
mm, the lower bottom is 3 mm, and is a substantially trapezoidal shape, and two protrusions are formed in a pair. The pair of groove fences 2 are arranged so as to face each other so that the portions corresponding to the lower bottoms of the groove fences are adjacent to each other
Also, the upper base (tip) of the facing groove fence 2 is 1
It was formed so as to open a space of mm.

By using the method for manufacturing a tire molding die of the present invention shown in FIG. 2, a non-basic shape (groove fence shape) can be easily and highly accurately formed in the basic partial mold. By combining a basic partial mold having a basic shape with a non-basic partial mold having a non-basic shape,
It was possible to easily, efficiently and inexpensively manufacture a mold for molding a tire in which a part of the tire was deformed into a non-basic shape (predetermined design) different from the basic shape.

Example 2 A basic partial mold 11 as shown in FIG. 12 (a) was manufactured using the method for manufacturing a tire mold of the present invention shown in FIG.
A slip mark 12 having a non-basic shape as shown in FIG. 12D was formed on the basic partial mold 11. 12
(A) is a perspective view of a basic partial mold in which only a basic shape is formed on the surface, (b) is a cross-sectional view of a VV portion of (a),
(C) is a perspective view showing a non-basic partial mold in which slip marks are formed on the surface, (d) is a cross-sectional view of the VV portion of (c), (e) is a partially enlarged view of (d), (F) is a front view of a slip mark.

The basic partial mold 11 has a height of 100 mm,
The outer circumference is R315, two ribs (main grooves) 30 are provided on the surface, and 16 basic partial molds 11 are combined to form an overall mold that is an inverted shape of the tire molding mold. In this embodiment, the slip mark 12 is
On the surface of this whole mold, six molds were arranged at a layout period different from the basic shape. The cross-sectional shape of the slip mark 12 is
It has a substantially inverted trapezoidal shape with an upper bottom of 2 mm, a lower bottom of 8 mm, and a height of 10 mm. In addition, as shown in FIG.
Has a peripheral dimension of 16 × 16 × 10 mm. As shown in FIG. 14, the basic partial mold 11 has a diameter of 10 m.
The through hole 19 was opened using the drill 15 of m.

Basic partial mold 11, slurry 14 (see FIG.
The reference material) and the reversing member 13 were formed of the same materials as in Example 1.

The slip mark 12 can be easily formed on the basic partial mold 11 by the manufacturing method of the tire molding die of the present invention shown in FIG. 5, and the basic partial mold 11 having a basic shape and the non-basic basic mold 11 can be formed. By combining with a non-basic partial mold 16 (see FIG. 12C) having a shape (slip mark), a tire in which a part of the basic shape (basic design) is transformed into a non-basic shape (predetermined design) is molded. It was possible to easily, efficiently and inexpensively manufacture a die for this.

Example 3 A method for manufacturing the tire mold of the present invention shown in FIG. 9 in which the through hole 19 of the basic partial mold 11 in the manufacturing method of Example 2 was formed to have a diameter of 4.5 mm. Was used to fill the slurry (uncured mold material) 14 using a funnel 37 through a hollow cylindrical body 35 having an outer diameter of 4 mm. In this embodiment, a resin straw is used as the hollow cylindrical body 35.

As described above, the amount of the slurry 14 can be reduced by reducing the diameter of the through hole 19 and using the hollow cylindrical body 35 having a diameter similar to that of the through hole 19.
Further, by reducing the diameter of the through hole 19, the recess formed on the surface of the basic partial mold 11 can also be made small, so that only a minute portion of the surface of the basic partial mold is deformed into a non-basic shape. Is effective for.

Example 4 A cross section of a basic partial mold 21 as shown in FIG.
6, the sipe blade 22 is formed according to the steps shown in FIGS. 7A to 7G, and in the subsequent steps, a hollow cylindrical body for slurry filling as shown in FIG. 10B. The slurry was charged via 35. Basic part mold 2
1, the slurry 24 (see FIG. 7) and the reversal member 23 are formed by using the same material as in Example 1, and the basic partial mold 21 has a height of 106 mm, an outer circumference of R320, and a diameter of the through hole 14. Is 10 mm, and the slurry 24 is passed through a hollow cylindrical body (straw) having a diameter of 9.5 mm (see FIG. 7).
Was filled. Then, the inside of the hollow cylindrical body (straw) 35 was pressurized for 15 minutes by the pressure air having a pressure of 0.122 MPa. Immediately before the curing of the slurry 24 (see FIG. 7), the hollow cylindrical body 35 (straw) is extracted, and the sipe blade 2 is removed.
2 is a cross section, a non-basic partial mold 16 embedded in the joining surface 26
Was formed.

With such a manufacturing method, the sipe blade 22 can be easily formed on the basic partial mold 21, and the basic partial mold 21 having a basic shape and the non-basic partial mold having a non-basic shape (sipe blade) are formed. By combining with 16, it was possible to easily and efficiently manufacture a mold for molding a tire in which a part of the basic shape is deformed into a non-basic shape, at low cost.

[0097]

As described above, according to the present invention, in a method for manufacturing a tire molding die using a precision casting method, when forming a whole mold by combining partial molds, one of the tire surface shapes is A mold for molding a tire having a surface shape of a shape (basic shape) to which a non-basic shape is added (a part of the basic shape is transformed to a non-basic shape) is simple and efficient. It is possible to provide a method for manufacturing a tire molding die that can be manufactured at a relatively low cost.

[Brief description of drawings]

FIG. 1 is an explanatory view schematically showing a basic partial mold used in an embodiment of a method for manufacturing a tire molding die according to the present invention, in which (a) is a basic basic mold having only a basic shape formed on its surface. A perspective view showing a partial mold, (b) a partially enlarged view of (a),
(C) is a partially enlarged view of a non-basic partial mold in which a groove fence is formed on the surface.

FIG. 2 is an explanatory view showing an embodiment of a method for manufacturing a tire molding die of the present invention in the order of steps.

FIG. 3 is a perspective view showing a forming position of a concave portion formed in a desired portion of a basic partial mold used in one embodiment of a method for manufacturing a tire molding die of the present invention, and FIG. When forming so as to correspond to the basic shape, (b) shows the case where two or more adjacent non-basic shapes are simultaneously formed.

FIG. 4 is an explanatory view schematically showing a non-basic partial mold in which a non-basic shape is used, which is used in another embodiment of the method for manufacturing a tire molding die of the present invention, in which (a) is a perspective view. ,
(B) is sectional drawing in the XX line of (a), (c) is a partially expanded view of (b).

FIG. 5 is an explanatory view showing another embodiment of the method for manufacturing a tire molding die of the present invention in the order of steps, in which a non-basic shape such as a slip sign is added to a part of the basic shape of the surface of the basic partial mold. It is explanatory drawing which shows the process of giving and forming a non-basic partial template in process order.

FIG. 6 is an explanatory view schematically showing a non-basic partial mold in which a sipe blade is embedded, which is used in another embodiment of the method for manufacturing a tire molding die of the present invention.

FIG. 7 is an explanatory view showing another embodiment of the method for manufacturing a tire molding die of the present invention in the order of steps.

FIG. 8 is an explanatory diagram showing a modification of the embodiment shown in FIGS. 7 (e) to 7 (i).

FIG. 9 is an explanatory view showing another embodiment of the method for manufacturing a tire molding die of the present invention in the order of steps.

FIG. 10 is an explanatory view showing a method of pressurizing the inside of a hollow cylinder in another embodiment of the method for manufacturing a tire molding die of the present invention, wherein (a) and (b) show a case where a cylinder is used, (C) shows the case where a long hollow cylinder is used, respectively.

FIG. 11 is an explanatory view schematically showing a partial mold used in Example 1 of the method for manufacturing a tire molding die of the present invention,
(A) is a perspective view showing a basic partial mold having only a basic shape formed on the surface, (b) is a partially enlarged view of (a), and (c) is a non-basic partial mold having a groove fence formed on the surface. Partly enlarged view of (d), sectional view of (c), (e) (c)
FIG.

FIG. 12 is an explanatory view schematically showing a partial mold used in Example 2 of the method for manufacturing a tire molding die of the present invention,
(A) is a perspective view showing a basic partial mold in which only a basic shape is formed on the surface, (b) is a cross-sectional view taken along the line VV of (a), and (c) is a non-slip mark formed on the surface. A perspective view showing a basic partial mold, (d) is a cross-sectional view taken along line VV of (c), (e) is a partially enlarged view of (d), and (f) is a plan view showing dimensions of slip marks. is there.

FIG. 13 is an explanatory view schematically showing a reversing member used in Example 2 of the method for manufacturing a tire molding die of the present invention.

FIG. 14 is a perspective view showing a step of forming a through hole in a basic partial mold in Example 2 of the method for manufacturing a tire molding die of the present invention.

FIG. 15 is an explanatory view schematically showing a non-basic partial mold used in Example 4 of the method for manufacturing a tire molding die of the present invention.

FIG. 16 is an explanatory diagram showing a method of manufacturing a conventional tire molding die in the order of steps.

FIG. 17 is an explanatory diagram showing, in the order of steps, steps of embedding a sipe blade in a partial mold using a conventional method for manufacturing a tire molding die.

[Explanation of symbols]

1 ... partial mold, 2 ... groove fence, 3 ... inversion member,
4 ... slurry (uncured mold material), 6 ... scraper,
7 ... Recessed portion, 8 ... Marking line, 9 ... Surplus portion, 10 ... Rib (main groove), 11 ... Basic portion mold, 12 ... Non-basic shape, 1
3 ... Inversion member, 14 ... Slurry (uncured template material), 1
5 ... Drill, 15 '... Rubber band, 16 ... Non-basic partial mold, 17 ... Recessed portion, 19 ... Through hole, 20 ... Non-basic shape forming part of basic partial mold, 21 ... Basic partial mold, 22 ... Sipe blade, 22 '... Sipe blade inverted shape, 23
... Inversion type, 24 ... Slurry (uncured template material), 25 ... Drill, 26 ... Bonding surface, 27 ... Recessed portion, 28 ... Slurry (uncured template material), 29 ... Through hole, 30 ... Rib (main groove) ,
35 ... Hollow cylinder, 36 ... Cylinder, 37 ... Funnel.

Claims (5)

[Claims] 1. Forming a plurality of partial molds each having a shape forming a part of the surface shape of a tire as the surface shape,
A total mold is formed by combining a plurality of the partial molds so as to have the shape of the tire, and the tire is obtained by pouring a molten metal into a gap between the whole mold and the molding frame by surrounding the whole mold with a casting frame and curing the molten metal. A method for producing a tire molding die that is an inversion type, wherein a plurality of basic partial molds having a shape (basic shape) forming a part of the surface shape of the tire as its surface shape is formed, Of the basic partial mold of, at least a portion of the surface of one or more of the basic partial mold to form a recess, a reversal member having a surface shape that is reversed non-basic shape different from the basic shape, A gap is formed between the concave portion of the basic partial mold and the surface of the reversing member having the inverted shape of the non-basic shape so as to be close to the concave portion of the basic partial mold. The mold material is filled and cured, and at least part of the surface shape of the base section mold,
Forming a non-basic partial mold having the non-basic shape as its surface shape by transforming from the basic shape to the non-basic shape, the basic partial mold having the basic shape as its surface shape, and the non-basic shape A tire molding characterized by comprising combining the non-basic partial mold having as a surface shape thereof to form the whole mold having a shape obtained by adding the non-basic shape to the basic shape as a surface shape thereof. Method for manufacturing metal mold. 2. The method for manufacturing a tire molding die according to claim 1, wherein the basic partial mold is formed from a self-curing mold material. 3. A through hole penetrating from the bottom surface of the recess formed in at least a part of the surface of one or more of the basic partial molds among the plurality of basic partial molds to the back surface of the basic partial molds. Then, from the opening on the back side of the basic partial mold of the through hole, via the through hole, between the concave portion of the basic partial mold and the surface having the inverted shape of the non-basic shape of the reversal member The method for producing a tire molding die according to claim 1, wherein the gap is filled with the uncured mold material. 4. A hollow cylinder made of a material that does not allow the solvent to permeate is added to the uncured template material by adding a solvent for softening it, and the through hole is formed on the rear side of the basic partial template. The method for manufacturing a tire mold according to claim 3, wherein the gap is filled with the uncured mold material containing the solvent via the hollow cylindrical body. 5. The hollow space through the hollow cylindrical body,
After filling the uncured mold material containing the solvent, the hollow cylindrical body is pressurized from the end side of the back side of the basic partial mold, the uncured mold material containing the solvent The method for manufacturing a tire molding die according to claim 4, wherein the space is filled with no space.