JP5243157B2 - Manufacturing method of casting for tire mold - Google Patents

Description

  The present invention relates to a method for manufacturing a casting for a tire molding mold of a sectional mode type, and in particular, it is difficult for twisting and warping deformation of each block casting at the time of casting shrinkage, and there is little difference in shrinkage rate between the top and bottom, However, the present invention relates to a method for manufacturing a casting for a tire molding die, which can have a relatively short molten metal solidification time and easily obtain a sound casting.

  Tire molding dies are generally produced by casting because of the complexity of the design and the ability to cast thin plates such as sipes and blades made of dissimilar metal materials. The plaster casting method is widely adopted. Other reasons for adopting the gypsum casting method are (1) the ability to produce castings with melting points up to the level of aluminum alloys with high dimensional accuracy, and (2) the ease of cutting and assembly at the gypsum mold stage. (3) It is possible to cope with casting of sipe and blade with a high degree of freedom, and (4) complicated design shape can be accurately transferred by casting inversion from a rubber mold.

  There are two types of mold division structures for tire molds: a two-piece mold that divides into two in the tire width direction and a sectional mold that divides into 7 to 11 in the tire circumferential direction. Of these, sectional molds are widely used that have low resistance during tire molding and high dimensional accuracy. As a casting method of the sectional mold, for example, Patent Document 1 discloses a molten metal pouring method using a low pressure casting method, Patent Document 2 discloses a molten metal pouring method using a dedicated chute in gravity casting, and Patent Document 3 describes gravity. A molten metal pouring method using a runner surface plate that can be repeatedly used in casting is disclosed.

  The characteristics of these methods are: (1) After casting, processing and forming a sectional mold, (2) Since the outlet is concentrated on the lower surface side, the melt solidification time is different at the top and bottom for each sectional mold. (3) Utilizing a casting frame as a cooling mold.

FIG. 19 illustrates a process example when a tire mold is manufactured by a sectional mold. (A) is a top view of the ring casting 100 of a tire mold, (B) is the sectional view. In this process example, a tire mold is first cast, then divided into individual block castings 101 by sector division, and then the outer periphery is processed into a sectional mold. According to this method, it is possible to perform both ring-shaped simultaneous casting of a plurality of block castings and casting of one block casting.
JP-A-57-58968 (Claims etc.) Japanese Patent No. 2796010 (Claims etc.) JP 2007-144480 A (Claims etc.)

  When casting a tire mold casting with a sectional mold, twisting and warping deformation in the sectional mold block casting is less likely to occur when the casting shrinks, and the casting for the tire mold can be cast with one ring. There is an advantage that it is good. However, in conventional sectional molds, there is a difference between the upper and lower surfaces of the molten metal solidification time due to the presence of the outlet on the lower or upper surface side, and the casting shrinkage increases where solidification is slow, resulting in a difference in the upper and lower mold dimensions. There was a problem that it was easy.

  Therefore, the object of the present invention is that twisting and warping deformation of each block casting hardly occur at the time of casting shrinkage, and there is little difference in shrinkage rate at the top and bottom, and even a large property can have a relatively short molten metal solidification time. It is providing the manufacturing method of the casting for tire molding dies which is easy to obtain a sound casting.

  As a result of intensive studies in order to solve the above-mentioned problems, the present inventor has found that the above object can be achieved by adopting the following configuration, and has completed the present invention.

That is, the method for producing a casting for a tire molding die of the present invention is a method for producing a casting for a tire molding die of a sectional mold type in which a mold is opened and closed by dividing into a plurality in the circumferential direction.
Including a step of individually casting the divided block castings to produce them, and in this step, an upper surface portion, a lower surface portion, and circumferentially divided surfaces on both sides that surround the design surface that is a contact surface with the mold from four sides The molten metal is poured into a mold in which a cooling metal is disposed so as to continuously surround at least the design surface on the four surfaces.

  In this invention, it is preferable to arrange | position the said cooling metal facing each other symmetrically with respect to four surfaces of the said upper surface part, a lower surface part, and the circumferential direction division surface of both sides. Further, it is preferable that a pair of outlets for the mold is arranged symmetrically on the upper surface part and the lower surface part, or a pair of outlets for the mold is arranged symmetrically on the circumferential dividing surfaces on both sides. Furthermore, it is preferable to form a runner for supplying molten metal to the hot water outlet and / or the hot water outlet inside the cooling metal.

  According to the present invention, twisting and warping deformation of each block casting hardly occur at the time of casting shrinkage, and there is little difference in shrinkage rate between the upper and lower sides, and even a large property can have a relatively short molten metal solidification time, and sound. It is possible to provide a method for producing a casting for a tire molding die that is easy to obtain a casting.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
(First to third embodiments)
FIG. 1 (A) is a perspective view of the block casting 1 according to the first embodiment of the present invention. Of the design surface 6 side of the upper surface 2a of the block casting 1, the substantially half surface of the lower surface 2b, the back surface 4 of the lower surface 2b, and the circumferentially divided surfaces of both sides, the back surface 4 side of one circumferentially divided surface 3a. A chiller for increasing the cooling rate inside the block casting 1 is disposed on the half surface and the substantially half surface on the back surface 4 side of the other circumferentially divided surface 3b. In the figure, the portion where the chiller abuts is indicated by hatching. In the present invention, it is important to form the mold so that the cooling metal continuously surrounds the design surface 6 as shown. Thereby, the solidification of the said site | part rapidly arises at the time of the molten metal solidification after casting, and the said solidified site | part functions as a restraint tool at the time of the solidification and cooling shrinkage | contraction of the block casting 1 whole. As a result, the produced block casting 1 is less likely to be deformed such as twisting and warping, and the difference in shrinkage between the upper surface portion 2a and the lower surface portion 2b is reduced.

  In addition, when the tire mold is ring-cast by the conventional sectional mold as shown in FIG. 19, a hot water hole portion must be formed on either the upper surface portion or the lower surface portion, and divided in the circumferential direction. Since there is no surface, the cooling metal cannot be brought into contact with the circumferentially divided surface. Therefore, it is impossible to form a mold so that the cooling metal continuously surrounds the design surface. Therefore, in the case of conventional sectional molds, the casting ring structure itself minimizes the occurrence of twisting and warping deformation during shrinkage, but solidification on the feeder side is delayed, and there is a difference in shrinkage rate between the upper surface and the lower surface. It was inevitable that the size would increase.

  In the present invention, with respect to the back surface 4 side, which is the facing surface of the design surface 6, there is no particular limitation on the arrangement of the cooling metal with respect to the block casting 1, even if the entire surface cooling metal other than the hole of the hot water 5 is contacted, Or it is good also as only a formwork, without arrange | positioning a cooling metal at all.

  FIG. 1B is a perspective view of a block casting 1 according to the second embodiment of the present invention. The entire upper surface portion 2a, the entire lower surface portion 2b of the block casting 1, and the design surface 6 side substantially half surface of one circumferential direction divided surface 3a among the circumferential direction divided surfaces on both sides, and the other circumference A cooling metal is disposed on the substantially half surface on the back surface 4 side of the direction dividing surface 3b. FIG. 1C is a perspective view of a block casting 1 according to the third embodiment of the present invention. Cooling metal is disposed on the design surface 6 side substantially half surface of the upper surface portion 2a of the block casting 1, the back surface 4 side substantially half surface of the lower surface portion 2b, and the entire circumferential dividing surfaces 3a and 3b on both sides. In these embodiments, similarly to the first embodiment, the cooling metal can continuously surround the design surface 6, and as a result, the solidification of the part rapidly occurs at the time of the solidification of the molten metal after casting. The said site | part functions as a restraint tool at the time of the solidification and cooling shrinkage | contraction of the block casting 1 whole.

(Fourth to eighth embodiments)
In the following fourth to eighth embodiments, preferred embodiments will be described in which opposed chillers are arranged symmetrically with respect to the four surfaces of the upper surface portion, the lower surface portion, and the circumferentially divided surfaces on both sides of the block casting 1. .

  FIG. 2A is a perspective view of a block casting 1 according to the fourth embodiment of the present invention. By disposing chillers on the entire upper surface portion 2a, the entire lower surface portion 2b of the block casting 1, and the entire circumferential dividing surfaces 3a and 3b on both sides, the opposing chillers are symmetrical with each other. Has been placed.

  FIG. 2B is a perspective view of the block casting 1 according to the fifth embodiment of the present invention. Cooling metal on the design surface 6 side approximately half surface of the upper surface portion 2a of the block casting 1, the design surface 6 side approximately half surface of the lower surface portion 2b, and the design surface 6 side approximately half surface of the circumferentially divided surfaces 3a and 3b on both sides. By arrange | positioning, the opposing cooling metal is arrange | positioned symmetrically, respectively.

  FIG. 2C is a perspective view of the block casting 1 according to the sixth embodiment of the present invention. Cooling metal is arranged on the back half 4 side of the upper surface 2a of the block casting 1, the back side 4 of the lower face 2b, and the back side 4 of the circumferentially divided surfaces 3a and 3b on both sides. Thus, the opposing chillers are arranged symmetrically.

  FIG. 2D is a perspective view of the block casting 1 according to the seventh embodiment of the present invention. Cooling metal is applied to the design surface 6 side approximately half surface of the upper surface portion 2a of the block casting 1, the design surface 6 side approximately half surface of the bottom surface portion 2b, and the back surface 4 side approximately half surface of the circumferentially divided surfaces 3a and 3b on both sides. By arrange | positioning, the chillers which oppose are arrange | positioned symmetrically, respectively.

  FIG. 2E is a perspective view of the block casting 1 according to the eighth embodiment of the present invention. Cooling metal is arranged on the back half 4 side of the upper surface 2a of the block casting 1, the back side 4 of the bottom face 2b, and the design side 6 half of the circumferentially divided surfaces 3a and 3b on both sides. By doing so, the opposing chillers are arranged symmetrically. In each figure, the portion where the chiller abuts is indicated by hatching.

  In the fourth to eighth embodiments, the chiller continuously surrounds the design surface 6, and thus the same effect as that of the invention according to the first embodiment can be obtained. In addition, in the fourth to eighth embodiments, the opposing chillers are arranged symmetrically on the four surfaces of the upper surface portion 2a and the lower surface portion 2b of the block casting 1 and the circumferentially divided surfaces 3a and 3b on both sides. Accordingly, the solidification of the molten metal from the upper surface portion 2a, the lower surface portion 2b, and the circumferentially divided surfaces 3a and 3b on both sides starts symmetrically at substantially the same time, and the block casting 1 is symmetrical in the vertical and horizontal directions (arrow direction). It becomes easy to obtain characteristics. There is no restriction | limiting in particular about arrangement | positioning of the cooling metal at the back surface 4 side of a casting.

  As described above, when aiming at a solidification form that is symmetrical in the vertical and horizontal directions (in the direction of the arrow) of the block casting 1, the hot water 5 must be installed on the back surface 4 side, and the molten metal on the back surface 4 side of the block casting 1. It is necessary to delay clotting. Therefore, it is not necessary to obtain the restraining effect of the solidification / cooling shrinkage of the entire block casting 1 by the molten metal initial solidified layer on the back surface 4, so that it is not necessary to install a cooling metal on the back surface 4 side.

(Ninth to 11th embodiments)
In the following ninth to eleventh embodiments, the pair of outlets for the mold are arranged symmetrically on the upper surface part and the lower surface part, or the pair of outlets for the mold are arranged symmetrically on the circumferential dividing surfaces on both sides. Embodiments will be described.

  Drawing 3 is a mimetic diagram showing arrangement of a tapping gate with respect to a mold of block casting 1 concerning a 9th embodiment of the present invention. In the preferred embodiment shown in the figure, a pair of hot water outlets 7 arranged symmetrically on the upper surface 2a and the lower surface 2b are formed on the upper surface 2a side and the lower surface 2b side edge of the design surface 6. The molten metal poured from the pouring port 10 is supplied to the pouring gate 7 through the throttle port 11 and one runner 8 by the gravity casting method.

  FIG. 4 is a schematic diagram showing the arrangement of the outlets with respect to the mold of the block casting 1 according to the tenth embodiment of the present invention. In the preferred embodiment shown in the figure, as in the ninth embodiment, a pair of outlets 7 arranged symmetrically on the upper surface portion 2a and the lower surface portion 2b are provided at the upper surface portion 2a side and the lower surface portion 2b side edge of the design surface 6. Is formed. The molten metal poured from the pouring port 10 is supplied to the pouring gate 7 through the throttle port 11 and the runner 8 divided into two hands by the gravity casting method.

  FIG. 5 is a schematic diagram showing the arrangement of the outlets with respect to the mold of the block casting 1 according to the eleventh embodiment of the present invention. In the preferred embodiment shown in the figure, two pairs of hot water outlets 7 arranged symmetrically on the upper surface 2a and the lower surface 2b are formed on the upper surface 2a side and the lower surface 2b side edges of the design surface 6, respectively. The molten metal poured from the pouring port 10 is supplied to the pouring gate 7 through the throttle port 11 and the runner 8 divided into two hands by the gravity casting method.

  In the ninth to eleventh embodiments, it is premised that the cooling metal continuously surrounds the design surface 6, and thus the same effect as that of the invention according to the first embodiment can be obtained. In addition, in any of the ninth to eleventh embodiments, the molten metal heat input (overheating) state from the hot water outlet 7 from the start of pouring to the completion of pouring can be made even in the vertical and horizontal directions, and the block casting 1 is advantageous in that it is easy to obtain symmetrical characteristics in the vertical and horizontal directions.

(Twelfth to fifteenth embodiments)
In the following twelfth to fifteenth embodiments, preferred embodiments in which both or one of the outlet and the runner that supplies the molten metal to the outlet are formed inside the chiller 12 will be described.

  FIG. 6 is a schematic view showing the arrangement of the outlets with respect to the mold of the block casting 1 according to the twelfth embodiment of the present invention. In the illustrated preferred embodiment, the tap 7 is formed on the side edge of the upper surface 2 a of the design surface 6. The molten metal poured from the pouring port 10 is supplied to the pouring gate 7 through the throttle port 11 and one runner 8 by the gravity casting method. Here, in the twelfth embodiment, the tap 7 is formed inside the chiller 12, that is, through the chiller 12.

  FIG. 7 is a schematic diagram showing the arrangement of the outlets with respect to the mold of the block casting 1 according to the thirteenth embodiment of the present invention. In the preferred embodiment shown in the figure, a pair of hot water outlets 7 arranged symmetrically on the upper surface 2a and the lower surface 2b are formed on the upper surface 2a side and the lower surface 2b side edge of the design surface 6. The molten metal poured from the pair of pouring ports 10 is supplied to the pouring gate 7 through separate throttle ports 11 and runners 8 by gravity casting. Here, in the thirteenth embodiment, the tap 7 is formed in the inside 12 of the chiller.

  In the twelfth and thirteenth embodiments, it is premised that the cooling metal 12 continuously surrounds the design surface 6, and thus the same effects as those of the invention according to the first embodiment can be obtained. . In addition, in these embodiments, the pouring gate 7 is installed in the cooling metal interior 12 so that the molten metal in the pouring gate 7 is solidified and cooled immediately after pouring is completed, and the pouring gate 7 is provided as in the twelfth embodiment. Even in the case where they are not symmetrically arranged in the vertical direction, the advantage that the block casting 1 solidifies and cools substantially uniformly in the vertical and horizontal directions as in the thirteenth embodiment can be obtained.

  FIG. 8 is a schematic diagram showing the arrangement of the outlets with respect to the mold of the block casting 1 according to the fourteenth embodiment of the present invention. The preferred embodiment shown is the same as the twelfth embodiment except that the runner 8 is formed inside the cooler 12.

  FIG. 9 is a schematic diagram showing the arrangement of the outlets with respect to the mold of the block casting 1 according to the fifteenth embodiment of the present invention. In the preferred embodiment shown in the figure, a pair of hot water outlets 7 arranged symmetrically on the upper surface 2a and the lower surface 2b are formed on the upper surface 2a side and the lower surface 2b side edge of the design surface 6. The molten metal poured from one pouring port 10 is supplied to the pouring gate 7 through a runner 8 that is divided into two portions with the throttle port 11 by gravity casting. Here, in the fifteenth embodiment, both the hot water outlet 7 and the runner 8 are formed inside the cooling metal 12.

  In the fourteenth and fifteenth embodiments, the effects of the inventions according to the above twelfth and thirteenth embodiments can be further enhanced, and the trouble of having to attach and detach the external gate every time of casting can be saved. There is also an advantage of being able to do it.

  In addition, the method for manufacturing a sectional mold type casting for tire molding mold according to the present invention is characterized by a process of individually casting the divided block castings, and is characterized by other processes such as a prototype manufacturing process. The steps such as the rubber mold reversal step, the gypsum mold reversal step, the mold drying step, the mold separation step, and the mold matching step can be appropriately performed according to known methods.

Hereinafter, the present invention will be described in more detail with reference to examples.
Example 1
FIG. 10 is a perspective view showing a casting method of the block casting 1 of the first embodiment. As shown in the figure, a cooling metal 12 is arranged on the four casting frames of the upper surface portion 2a, the lower surface portion 2b and the circumferentially divided surfaces 3a and 3b of the block casting 1 so as to continuously surround the design surface 6. . The cast frame surrounding the block casting 1, the runner 8, the tap 7 and the chill metal 12 was all made of a sand mold made of water glass hardened silica sand. The cooling metal contact area rate of the upper surface portion 2a is 80%, the cooling metal contact area rate of the lower surface portion 2b is 50%, and the cooling metal contact area of the circumferentially divided surfaces 3a and 3b is 60%. A block casting 1 was produced with a casting frame and cooling metal temperature of 25 ° C. and a casting start temperature of 680 ° C. In addition, AC4C (aluminum alloy) was used as the alloy for the casting for the tire mold.

(Example 2)
FIG. 11 is a perspective view illustrating a casting method of the block casting 1 of the second embodiment. As shown in the figure, the cooling metal 12 is symmetrically arranged so as to continuously surround the design surface 6 in the four-sided casting frame of the upper surface portion 2a, the lower surface portion 2b and the circumferentially divided surfaces 3a and 3b of the block casting. Arranged. The cast frame surrounding the block casting 1, the runner 8, the tap 7 and the chill metal 12 was all made of a sand mold made of water glass hardened silica sand. The cooling metal contact area ratio of the upper surface portion 2a is 50%, the cooling metal contact area ratio of the lower surface portion 2b is 50%, and the cooling metal contact area of the circumferentially divided surfaces 3a and 3b is 60%. A block casting was produced by setting the casting frame and cooling metal temperature to 25 ° C. and casting start temperature to 680 ° C. In addition, AC4C (aluminum alloy) was used as the alloy for the casting for the tire mold.

(Example 3)
FIG. 12 is a transparent perspective view showing a casting method of the block casting 1 of the third embodiment. As shown in the drawing, the upper surface 2a, the lower surface 2b, the circumferentially divided surfaces 3a and 3b, the runner 8, the outlet 7 and the casting frame (lower mold) 13 surrounding the cooling metal 12 are all made of cast iron. did. The casting frame (upper mold) on the back side of the block casting was made of water glass hardened silica sand. Moreover, the runner 8 and the tap 7 were dug into the lower structure. Block castings with an upper surface portion 2a, a lower surface portion 2b and circumferentially divided surfaces 3a, 3b having a chill metal contact area ratio of 100%, a casting mold and casting frame temperature of 200 ° C., and a casting start temperature of 680 ° C. Produced. In addition, AC4C (aluminum alloy) was used as the alloy for the casting for the tire mold.

(Comparative Example 1)
FIG. 13 is a perspective view showing a conventional casting method for a tire mold casting of Comparative Example 1. FIG. As shown in the figure, a ring-shaped runner 18 was installed on the lower side of the ring, and a hot water outlet 17 was arranged on the top thereof. The contact area ratio of the chill metal is 100% of the entire surface of the outer peripheral cylindrical surface of the ring casting, about 40% in the donut-shaped inner side of the lower plane, and 0% (no chill metal contact) in the upper surface portion 22a where the hot water 15 is generated. did. In addition, a block casting was produced at a casting mold temperature and a casting frame temperature of 200 ° C. and a casting start temperature of 680 ° C. In addition, AC4C (aluminum alloy) was used as the alloy for the casting for the tire mold.

(Comparative Example 2)
FIG. 14 is a perspective view showing a casting method of the block casting 1 of Comparative Example 2. As shown in the drawing, two chillers 12 are arranged on each of the four cast frames of the upper surface portion 2a, the lower surface portion 2b and the circumferentially divided surfaces 3a and 3b of the block casting. The contact area of the chillers was all 30%. Moreover, the block casting 1 was produced by setting the casting mold and casting frame temperature to 25 ° C. and casting start temperature to 680 ° C. In addition, AC4C (aluminum alloy) was used as the alloy for the casting for the tire mold.

(Formation method of the design surface that is the contact surface with the mold)
A rubber mold was manufactured by placing a wooden mold on which a tread pattern was formed in a mold and pouring a silicone rubber material into the mold. The wood mold was made of synthetic wood (basic shrinkage setting: 11.5 / 1000), and the rubber mold was a gypsum-lined silicone rubber mold (rubber layer thickness 15 mm).

  By pouring gypsum (G-1 foamed gypsum manufactured by Noritake Gypsum: 70% water mixing, 50% foaming increase) into the rubber mold, the design surface φ600 ± 20 mm, tire width dimension 195 ± 30 mm, casting thickness 70˜ A design surface portion that contacts a mold having a size of 100 mm, a total casting height of 300 ± 30 mm, and a sector division number of 9/1 ring was manufactured. Casting was performed using this design surface portion, and block castings of Examples 1 to 3 and Comparative Example 2 and tire mold castings of Comparative Example 1 were obtained. The basic dimensions of the tire mold casting and the manufacturing method thereof are shown in Table 1 below.

  Regarding the as-cast dimensional accuracy of the castings for tire hardware manufactured through Examples 1 to 3 and Comparative Examples 1 and 2, four items of string dimensions, twist, circumferential warpage and width direction warpage were evaluated according to the following evaluation methods. .

<String dimensions>
FIG. 15 is an explanatory diagram of the chord dimension measurement. The upper chord dimension, the central chord dimension, and the lower chord dimension of each of the obtained casts for tire hardware were measured, and the average of the differences from the respective drawing dimensions was calculated. In addition, the difference between the upper chord dimension and the lower chord dimension was calculated. In addition, the difference from the drawing value of the chord dimension is
String dimensional difference = found casting actual measurement size-drawing size. A positive value means that the casting chord dimension is larger than the drawing value. The difference between the top and bottom is
Difference between top and bottom = lower chord dimension-upper chord dimension. A positive value means that the upper chord dimension is smaller.

<Twist>
FIG. 16 is an explanatory diagram of twist measurement. By measuring the roundness of the as-cast product, difference values from theoretical dimensions were calculated at four points (A to D) in the vicinity of the upper and lower end portions of the block cast product. The total absolute value of the obtained difference values (| + A | + | −B | + | −C | + | + D |) was used as the amount of twist, and the amount of twist was evaluated.

<Circumferential warpage>
FIG. 17 is an explanatory diagram of circumferential warpage measurement. By measuring the roundness, the amount of unevenness (X, Y) from the theoretical dimension in the circumferential direction of one sector block was calculated, and the amount of warpage in the circumferential direction = −X or + Y was evaluated.

<Width warpage>
FIG. 18 is an explanatory diagram of the measurement of warpage in the width direction. By measuring the width direction R shape, the amount of unevenness (X, Y) from the theoretical dimension in the width direction of one sector block was calculated, and the amount of warpage in the circumferential direction = −X or + Y was evaluated.
The obtained results are summarized in Table 2.

  From Table 2, Comparative Example 1 (conventional ring casting) has good twist, circumferential warpage, and width direction warpage characteristics (both average value and variation are small), but the difference in chord dimension between the top and bottom is the largest. It was. Further, in Comparative Example 2 (conventional block casting), although the string size difference between the upper and lower sides was small, the twisting, circumferential direction and width direction warping characteristics were poor.

  On the other hand, in Example 1, the string dimension difference was smaller than that in Comparative Example 1, and twisting and warping deformation could be suppressed more than in Comparative Example 2. That is, it can be seen that it is possible to provide a block casting method in which twisting and warping deformation during casting shrinkage hardly occur and the shrinkage rate difference between the upper and lower dies of the sectional mold is small. Further, in Example 2, the upper and lower chord dimension difference could be further suppressed as compared with Example 1. Further, in Example 3, twisting and warping were similar to ring casting, but the difference in the upper and lower chord dimensions could be greatly improved compared to ring casting.

  As described above, according to the present invention, even if a block casting method is used, a dimensional accuracy characteristic equivalent to or higher than that of the ring casting method can be obtained, which is an advantage of the block casting method. You can make the most of it.

It is a see-through | perspective perspective view which shows the block casting which concerns on one embodiment of this invention. It is a see-through | perspective perspective view which shows the block casting which concerns on other embodiment of this invention. It is a see-through | perspective perspective view which concerns on the manufacturing method of the casting for tire molding dies of other embodiment of this invention. It is a see-through | perspective perspective view which concerns on the manufacturing method of the casting for tire molding dies of other embodiment of this invention. It is a see-through | perspective perspective view which concerns on the manufacturing method of the casting for tire molding dies of other embodiment of this invention. It is a see-through | perspective perspective view which concerns on the manufacturing method of the casting for tire molding dies of other embodiment of this invention. It is a see-through | perspective perspective view which concerns on the manufacturing method of the casting for tire molding dies of other embodiment of this invention. It is a see-through | perspective perspective view which concerns on the manufacturing method of the casting for tire molding dies of other embodiment of this invention. It is a see-through | perspective perspective view which concerns on the manufacturing method of the casting for tire molding dies of other embodiment of this invention. 3 is a perspective view showing the manufacturing method of Example 1. FIG. 6 is a perspective view showing the manufacturing method of Example 2. FIG. 6 is a perspective view showing the manufacturing method of Example 3. FIG. 6 is a perspective view showing a manufacturing method of Comparative Example 1. FIG. 10 is a perspective view showing a manufacturing method of Comparative Example 2. FIG. It is explanatory drawing of a chord dimension measurement. It is explanatory drawing of torsion measurement. It is explanatory drawing of the circumferential direction curvature. It is explanatory drawing of the width direction curvature. FIG. 6 is a process diagram for producing a tire mold by a sectional mold by a conventional method.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,101 Block casting 2a, 22a Upper surface part 2b Lower surface part 3a, 3b Circumferential direction division surface 4 Back surface 5, 15 Hot water 6 Design surface 7, 17 Hot water outlet 8, 18 Runner 10 Pouring port 11 Restriction port 12 Cooling metal 13 Lower mold 14 Upper mold 100 Ring casting

Claims (5)

In the method of manufacturing a casting for a tire molding mold of a sectional mold type that performs opening and closing operations of the mold by dividing into multiple pieces in the circumferential direction,
Including a step of individually casting the divided block castings to produce them, and in this step, an upper surface portion, a lower surface portion, and circumferentially divided surfaces on both sides that surround the design surface that is a contact surface with the mold from four sides A molten metal is poured into a mold in which a cooling metal is disposed so as to continuously surround at least the design surface on the four surfaces.   2. The method for manufacturing a casting for a tire molding die according to claim 1, wherein the cooling metal molds facing each other are arranged symmetrically with respect to the four surfaces of the upper surface portion, the lower surface portion, and the circumferential dividing surfaces on both sides.   The method for manufacturing a casting for a tire molding die according to claim 1 or 2, wherein a pair of outlets for the mold are arranged symmetrically on the upper surface portion and the lower surface portion.   The method for manufacturing a casting for a tire molding die according to claim 1 or 2, wherein a pair of outlets for the mold are arranged symmetrically on the circumferential dividing surfaces on both sides.   The method for producing a casting for a tire molding die according to any one of claims 1 to 4, wherein a runner for supplying molten metal to the outlet and / or the outlet is formed inside the cooling metal.

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