JP5352786B2 - Cast iron casting method, feeder, mold and mold making method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technique of an embedded feeding head type casting which can manufacture good castings of cast iron by preventing, for example, deformation of a weak part of a casting mold during cast iron casting, the occurrence of a dimensional error of casting, and the occurrence of shrinkage cavity. <P>SOLUTION: The mold is a vertically split casting mold which has a feeding head part 2 communicating with a product cavity 6. The feeding head part 2 comprises a molten metal filling part 3 that exerts a primary feeding effect, a pressure absorbing part 4 that is provided outside the molten metal filling part 3 and can absorb an increased pressure developed during molten metal solidification, and a partition wall 5 provided between the molten metal filling part 3 and the pressure absorbing part 4. The increased pressure can allow the partition wall 5 to bulge toward the pressure absorbing part 4 or to be split for opening. Accordingly, cast iron casting can be carried out while allowing the increased pressure of the molten metal caused in the molten metal filling part 3 to escape to the pressure absorbing part 4 and thus to avoid the application of excessive pressure to a product cavity 6. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a casting method for preventing “stretching”, “shrinkage nest” (also referred to as shrinkage nest), “seizure nest”, etc., which occurs in cast iron casting, a feeder part used for the implementation, and a feeder part thereof. Related to molds and methods for making the molds, especially those using vertical split molds divided on a vertical surface, and related to the technology belonging to the embedded type hot spring (also referred to as blind hot water) It is.

  In casting, metal generally shrinks during solidification, so that even if the mold is completely filled with molten metal using a good pouring method, a “shrinkage nest” occurs in the cast after solidification. In order to prevent this, it is necessary to provide a hot water supply that compensates for the lack of molten metal due to the liquid shrinkage and the solidification shrinkage. A method that does not use a feeder is also proposed (see, for example, Japanese Patent Application Laid-Open No. 10-85924), but it takes a lot of time to perform molding work and separation from sand after casting.

  Therefore, although a method using a feeder is generally used, cast iron, in particular, has a solidification shrinkage rate smaller than that of other metals and alloys due to the crystallization of graphite during solidification. Large volume expansion of molten metal. Therefore, in casting using cast iron, the installation method and size of the feeder are different from those of other metals or alloys.

  The installation method of the feeder is roughly divided into an open-type feeder and a non-open type, that is, an embedded-type feeder. The former has a structure as shown in FIG. Since this is not a hermetically sealed state, even if the molten metal pressure increases due to the volume expansion of the molten metal or the volume expansion of the foundry sand (decrease in the cavity volume), the increased pressure of the molten metal escapes to the open portion of the open-type feeder part. For this reason, the molten metal pressure in the mold is not increased, and the soft part of the mold is rarely deformed. However, since there is heat radiation from the upper part, the amount of hot water is increased or the “flickering heat retaining agent”. ", There is a problem that it is necessary to keep the hot water surface warm.

  On the other hand, the latter embedded-type feeder has a structure as shown in FIG. Since this is a sealed state, the volume expansion of the molten metal and the volume expansion of the foundry sand often increase the molten metal pressure in the mold and deform the soft portion of the mold. It is well known at the casting site that the increase in melt pressure in a sealed mold is stronger than expected. This phenomenon due to the increased pressure of the molten metal is referred to as the above-mentioned “molding”, which not only causes a dimensional defect of the cast product, but also causes a “shrinkage nest” in the cast product, thereby causing a product defect.

  In the case of a strong mold that does not cause “mold tension”, the molten metal pressure in the mold increases due to the volume expansion of the molten metal and the volume expansion of the foundry sand. The above-mentioned “burn-in” phenomenon occurs.

  In that case, in order to release the pressure and prevent the occurrence of defective products, it may be possible to use an open-type feeder. However, in addition to the above problems, it is necessary to apply pressure by hydraulic pressure etc. from the upper mold side in order to increase the strength of the mold even by molding automatic molding machine as well as molding by mold, It takes time to install the open-type feeder.

  Regarding these matters, Non-Patent Document 1 and Non-Patent Document 2, which will be described later, are documents that have been described in detail regarding casting engineering and cast iron castings, and are also familiar with the advantages and disadvantages of open-type and embedded-type feeders. There is a description.

Hideo Nakae, “Casting Engineering” (published by Sangyo Tosho Co., Ltd., new edition in April 2008, especially P.104, 109 etc.) Nobutaro Kayama “Cast Casting Textbook” (1968, 1st edition, 3 editions, especially P.217).

  Although not necessarily related to cast iron castings, patent applications for solving problems in casting include the following.

Here, in the prior art section of the specification, a method using a Williams core, a lost wax casting method, and the like are given, and as a means for solving those problems, the final of molten metal Proposals have been made for a casting method and a casting facility in which a suction port is provided on the mold surface in the vicinity of the filling portion, and the product is free of “shrinkage cavities” and other casting defects by depressurizing and pressurizing from the suction port.

Patent No. 4150764 Here, after the start of pouring a molten metal having a volume substantially equal to the desired cavity portion smaller than the volume of the cavity of the vent mold, before the molten metal is filled into the desired cavity, A technique has been proposed in which compressed gas is supplied from a gate and the desired cavity is filled with molten metal to be solidified.

Here, after filling the cavity from the molten metal supply path of the low-pressure casting mold, the molten metal supply path adjacent to the cavity is rapidly cooled to solidify the molten metal at that position, and then the feeder A technology that rapidly cools the surface layer of the molten metal in contact with the cavity wall surface while applying pressure to the molten metal in the cavity until the mold is opened by the pressure means provided in the section so that the surface layer of the molten metal is changed to a shell-shaped solidified layer. Has been proposed.

In addition, the patent literature relating to cast iron casting technology having a feeder part is related to a technology limited to special products such as casting of a wheel of a car, a track shoe of a crawler vehicle, or a cylinder piston of a diesel vehicle. For example, there are the following.
JP-A-5-69108 JP 7-132864 A JP-A-10-85924

  However, in the conventional methods and the methods described in the prior art documents, the open-type feeder and the non-open type, that is, the embedded-type feeder have the above-mentioned problems. In addition, those described in each of the above patent documents have limited applications, and it is necessary to provide a special accessory device such as a cooling circuit, a heating circuit, a compressed gas supply means, etc. in the feeder part, and the structure is enlarged.・ It becomes complicated.

  The present invention has been completed as a result of intensive studies aimed at solving the above problems. The purpose is to make use of the advantages of both open-type and embedded-type hot springs, overcoming each other's drawbacks, and making molds with a simple configuration without increasing the size and complexity of the equipment. Casting method for cast iron that is easy and can reduce the occurrence of mold tension, shrinkage nest, seizure, etc., and can also improve the heat retaining property of the feeder, the feeder part used therefor, the mold having the feeder part, and The method of forming the mold is to provide a mold using a vertically split mold.

A. The cast iron casting method according to the present invention is:
In the method using the vertical split mold 1 having the embedded feeder 2,
In the mold 1, the feeder part 2 that communicates with the product cavity part 6,
It is composed of a hollow molten metal filling portion 3 for exhibiting the original hot metal effect, and a hollow pressure absorbing portion 4 that is outside thereof and can absorb the increased pressure generated when the cast iron melt is solidified,
A partition wall 5 is provided between the molten metal filling portion 3 and the pressure absorbing portion 4 that can be deformed to the pressure absorbing portion 4 side with the increased pressure when the inside of the molten metal filling portion 3 exceeds a certain pressure,
When the molten cast iron is solidified, the increased pressure generated in the molten metal filling part 3 is released to the pressure absorbing part 4 by deformation of the partition wall 5, and cast iron is cast so that excessive pressure is not applied to the product cavity part 6. It is.

B. The first of the feeder parts used for carrying out the cast iron casting method according to the present invention is:
An embedded-type feeder 2 used for a vertically split mold 1,
A hollow molten metal filling portion 3 for demonstrating the original hot metal effect so as to communicate with the product cavity portion 6 by combining the molds 7 and 7 on both sides, and an increased pressure at the time of solidification of the molten cast iron on the upper portion thereof And a hollow pressure absorbing portion 4 capable of absorbing
A partition wall 5 is provided between the molten metal filling portion 3 and the pressure absorbing portion 4 that can be deformed to the pressure absorbing portion 4 side by the increased pressure when the inside of the molten metal filling portion 3 exceeds a certain pressure (for example, 1 to 3).

C. The second of the feeder part used for carrying out the cast iron casting method according to the present invention is:
An embedded-type feeder 2 used for a vertically split mold 1,
By combining the molds 7 and 7 on both sides, a hollow molten metal filling portion 3 for exerting an original hot metal effect so as to communicate with the product cavity portion 6 and an increased pressure at the time of solidification of the cast iron molten metal on the upper portion thereof. A hollow pressure absorbing part 4 that can be absorbed and a partition wall 5 made of foundry sand between the three and four parts,
The partition wall 5 can be deformed to the pressure absorbing portion 4 side by the increased pressure when the inside of the molten metal filling portion 3 exceeds a certain pressure due to the solidification of the molten cast iron (see, for example, FIGS. 4 to 6).

D. The mold used for carrying out the cast iron casting method according to the present invention is:
A vertically split mold 1 having an embedded feeder 2,
As the feeder 2 therefor, either a first one of the above-mentioned feeders B or a second one of the feeders C is used as a vertically split mold (for example, FIG. 1 to FIG. 1). (See FIG. 7).

E. The mold making method used for carrying out the cast iron casting method according to the present invention is:
In making vertical split molds by molding with a raw automatic molding machine,
Vertically-divided semi-cylindrical recesses 8, 8 that form hollow hollow metal-filled portions 3 for communicating with the product cavity portion 6 and exhibiting the original hot-water-feeding effect after being combined with the molds 7, 7 on each side, In the upper part, vertically divided semi-disc shaped portions 11 and 11 of casting sand that become the disc-shaped partition wall 5 after the union, and a hollow pressure absorbing portion 4 that can absorb the increased pressure at the time of solidification of the cast iron melt after the union Forming vertically divided semi-cylindrical recesses 9 and 9,
In addition, the partition wall 5 formed into a disk shape by combining both the molds 7 and 7 can be deformed to the upper pressure absorbing portion 4 side with an increased pressure when the inside of the lower molten metal filling portion 3 exceeds a certain pressure. Thus, the vertical split mold 1 is formed by forming the feeder part 2 (see, for example, FIGS. 4 and 5).

  In the above configuration, the deformation of the partition wall 5 includes a case where the partition wall 5 is cracked so as to be opened (for example, see FIG. 8) and a case where the partition wall 5 is not cracked but bulges to the pressure absorbing portion 4 side (for example, see FIG. 9). The partition wall 5 is preferably formed of foundry sand that forms the mold 1 (see, for example, FIGS. 4 to 7). However, the partition wall 5 is fixed as a disc-shaped single unit at a position closer to the upper part in the hollow portion. (For example, see FIGS. 1 to 3 above). Further, in the case where the cylindrical sleeve 15 is inserted, it may be fixed to the upper end edge thereof, or may be integrally formed with the sleeve.

  The molten metal filling portion 3 and the pressure absorbing portion 4 may have different diameters, but the volume of the pressure absorbing portion 4 should be larger than the volume that the molten metal expands and increases during solidification. Of course. The partition wall 5 is formed to be weaker than the strength of the mold 1 so that the partition wall 5 is deformed, that is, bulges or cracks toward the pressure absorbing portion before the mold 1 is broken, so that the opening 17 is formed. . The partition wall 5 is not limited to one, and may be two or more.

According to the present invention having the above-described configuration, the occurrence of “mold tension”, “shrinkage nest”, “seizure”, and the like, which have been a major problem in cast iron casting, is greatly reduced while having a simple configuration. The casting product 18 can be manufactured, and the heat retaining property of the feeder can be improved as compared with the open-type feeder.
This will be described in comparison with the conventional one.

  Since the buried type feeder is in a sealed state, the volume expansion of the molten metal and the volume expansion of the foundry sand increase the molten metal pressure in the mold. For this reason, with a conventional embedded mold feeder, the soft part of the mold is deformed, resulting in a “die tension” phenomenon, resulting in a defective dimension of the cast product, or a “shrinkage nest” in the cast product. Was a cause of product defects.

  Even in a strong mold that does not cause “mold tension”, the molten metal pressure in the mold increases due to the volume expansion of the molten metal and the volume expansion of the foundry sand. The “with” phenomenon occurred. In addition, when “shrinkage flaws” (shrinkage flaws) occur, they are often used as countermeasures for such flaws by enlarging the feeder, which further deteriorates the yield rate. .

  On the other hand, in the present invention, as described above, the embedded-type feeder 2 provided so as to communicate with the product cavity 6 in the mold 1 is replaced with the molten metal filling portion 3 for exhibiting the original feeder effect. The pressure absorbing part 4 that can absorb the increased pressure inside is provided adjacent to the pressure absorbing part 4, and the pressure between the molten metal filling part 3 and the pressure absorbing part 4 is increased by the increased pressure in the molten metal filling part 3. A partition wall 5 is provided that is deformed toward the absorber 4 side.

Therefore, according to the present invention,
B) The mold 1 having the advantages of the embedded type hot-water type can be easily and quickly formed with a simple structure at a cost almost equal to that of the conventional method.

  B) When the molten cast iron is filled together with the product cavity portion 6 into the molten metal filling portion 3 of the feeder portion 2, even if the molten metal pressure in the mold 1 increases due to the volume expansion due to solidification of the molten metal and the volume expansion of the foundry sand, The partition wall 5 opens to the pressure absorption part 4 side, and the molten metal filling part 3 and the pressure absorption part 4 communicate (for example, refer to FIG. 8 above). Moreover, even if the partition wall 5 bulges without opening to the pressure absorbing portion 4 side, the volume of the molten metal filling portion 3 increases (see, for example, FIG. 9 above). In any case, the volume of the molten metal filling part 3 increases, and the pressure in the molten metal filling part 3 due to the molten metal is lowered.

  C) Therefore, even though it is a sealed embedded feeder type, excessive pressure is not applied to the feeder part 2 and the product cavity part 6, so that deformation and breakage of the soft part of the mold 1 can be prevented. It is possible to eliminate the dimensional defect of the product and suppress the generation of the shrinkage nest and to manufacture a good cast product 18.

  D) Since the pressure in the molten metal filling portion 3 does not become excessive, it is possible to prevent the molten metal from infiltrating between the sand grains of the mold 1 and to eliminate the “seizure” phenomenon.

  E) Furthermore, unlike the open-type feeder, heat radiation from above can be avoided, so that the heat retaining property of the feeder can be improved, and the amount of molten metal can be reduced by reducing the amount of feeder. As a result, the yield rate of the product can be improved, and an energy saving effect can be exhibited and, in turn, it can contribute to environmental problems.

It is a vertical front view which shows the state before uniting both mold frames about the casting_mold | template which has an example of the feeder part which concerns on this invention. It is what was shown in FIG. 1, and is a vertical front view which shows the state after uniting both molds. It is a vertical side view of what was shown in FIG. It is a vertical front view which shows the state before uniting both molds about the casting_mold | template with the other example of the feeder part which concerns on this invention. It is what was shown in FIG. 4, and is a vertical front view which shows the state after uniting both molds. It is a vertical side view of what was shown in FIG. It is what was shown in FIG. 5, and is a vertical front view which shows the example which inserted the sleeve. It is an enlarged vertical front view which shows the state in which the partition cracked and opened with the increased pressure of the molten metal filling part. It is an enlarged vertical front view which shows the state which the partition swelled to the pressure absorption part side with the increase pressure of a molten metal filling part. It is a vertical front view at the time of an evaluation test of a cast product. It is a top view of what was shown in FIG. It is a schematic longitudinal cross-sectional front view which shows the casting_mold | template with an open mold feeder. It is a general | schematic longitudinal cross-sectional front view which shows the casting_mold | template with a buried type feeder.

  The present invention uses a vertically split mold 1 having an embedded mold feeder 2 and is formed so as to communicate with the product cavity 6 in the mold 1 when the molds 7 and 7 on both sides are combined. The molten metal filling portion 3 for exhibiting the original molten metal effect, and the hollow pressure absorbing portion outside the molten metal filling portion 3 that can absorb the increased pressure generated during solidification of the cast iron melt 4 and a disk shape that can be deformed between the molten metal filling portion 3 and the pressure absorbing portion 4 to the pressure absorbing portion 4 side with the increased pressure when the inside of the molten metal filling portion 3 exceeds a certain pressure. The increased pressure generated in the molten metal filling portion 3 during solidification of the cast iron melt is released to the pressure absorbing portion 4 and cast iron is cast so that excessive pressure is not applied to the product cavity portion 6.

1 to 3 show one embodiment of a mold having a feeder part according to the present invention.
The mold 1 is composed of two molds 7 and 7 having a vertical plane as in the known vertical division, and is molded using a molding sand by a green molding machine. There is a gate 13 opened at the top, and a runner 14 extends downward from the gate 13 and communicates with the product cavity 6. Here, the product cavity 6 has a cylindrical shape with an inner diameter of 100 mm and a height of 200 mm.

  A feeder part 2 is formed in communication with the upper part of the product cavity part 6. This hot metal part 2 has a hollow cylindrical molten metal filling part 3 that exhibits the original hot metal effect when the molds 7 and 7 on both sides are combined, and a hollow cylindrical shape that can absorb the increased pressure during solidification of the cast iron melt. And the pressure absorbing part 4.

  In other words, the hollow cylindrical molten metal filling portion 3 and the pressure absorbing portion 4 are formed by forming the vertically divided semi-cylindrical recesses 10 and 10 using casting sand in the respective mold frames 7 and 7. The hollow cylindrical portion formed at the time of combining 7 and 7 is divided into two in the vertical direction by inserting a disc-shaped partition wall 5. The size of the hollow cylindrical portion is set to 95 mm in inner diameter and 100 mm in height here.

  Then, on the inner peripheral walls of the vertically divided semi-cylindrical recesses 10 and 10, semi-concave grooves 12 and 12 that are annular when the molds 7 and 7 are combined are formed at a position 65 mm from the lower part. (See FIG. 1). By fitting and inserting the disk-shaped partition wall 5 into the annular grooves 12, 12, the lower part of the partition wall 5 is the molten metal filling part 3, and the upper part is the pressure absorbing part 4. To do.

  The partition wall 5 can be opened at an increased pressure as shown in FIG. 8 when the molten iron filled portion 3 exceeds a certain pressure when the cast iron melt is solidified, and here the outer diameter is 110 mm. The thickness is 7 mm.

4 to 6 show another embodiment of a mold having a feeder part according to the present invention.
The mold 1 is also composed of two molds 7 and 7 having a vertical plane, and is molded from foundry sand with a green molding machine in the same manner as a known vertical split.

  There is a gate 13 opened at the top, and a runner 14 extends downward from the gate 13 and communicates with the product cavity 6. Here, the product cavity 6 is cylindrical and has an inner diameter of 100 mm and a height of 200 mm.

  A feeder 2 is formed in communication with the upper portion of the product cavity 6, but the feeder 2 is different from that of the first embodiment. In each of the molds 7 and 7 on both sides, the vertically divided semi-cylindrical recesses 8 and 8 that become the hollow cylindrical molten metal filling portion 3 that communicates with the product cavity portion 6 and exhibits the original hot metal effect when combined. Further, on the upper part thereof, the vertically split semi-disc shaped portions 11 and 11 of the casting sand that become the disc-shaped partition wall 5 after the union, and the hollow short cylindrical pressure that can absorb the increased pressure at the time of solidification of the cast iron melt after the union The vertically-divided short semi-cylindrical recesses 9 and 9 that form the absorbing portion 4 are formed (see FIG. 4).

  Then, by combining the two molds 7 and 7, a cylindrical molten metal filling portion 3 is formed at the lower portion of the disc-shaped partition wall 5 and a cylindrical pressure absorbing portion 4 is formed at the upper portion. The filling portion 3 has an inner diameter of 95 mm and a height of 65 mm, and the pressure absorbing portion 4 has the same inner diameter and a height of 28 mm. In addition, the partition wall 5 is deformed to the pressure absorbing portion 4 side by an increased pressure when the inside of the molten metal filling portion 3 exceeds a certain pressure, and here, it is formed to have a strength capable of expanding as shown in FIG. The thickness of the partition wall 5 is 15 mm. In this way, the vertically split mold 1 with the feeder 2 shown in FIGS. 5 and 6 is formed.

  FIG. 7 shows a modification of the second embodiment, which is common in that the vertically split molds 7 and 7 have the molten metal filling portion 3, the pressure absorbing portion 4, and the partition wall 5 when combined. A cylindrical sleeve 15 is inserted into the filling portion 3.

  Here, the sleeve 15 is formed by using a resin agent such as dredged sand or waste paper as a binder, and has a cylindrical shape with an outer diameter of 95 mm, an inner diameter of 60 mm, and a height of 65 mm. I have to do it. Since other parts are as described in the above embodiment, the description is omitted to avoid duplication.

  In the figure, reference numeral 16 denotes a notch (notch groove) formed in the central portion of the upper surface of the partition wall. The depth is 2 mm here, but this notch 16 is not indispensable, and it may be necessary depending on the strength of the partition wall. Absent. Reference numeral 17 denotes an opening formed by dividing the partition wall 5, and 18 denotes a cast product.

  In any of the above embodiments, when the molten cast iron is poured into the mold 1, the partition wall 5 is caused by the increased pressure generated when the molten metal is solidified in the molten metal filling portion 3 of the feeder 2 provided inside. Since it breaks and bulges toward the opening or the pressure absorbing portion 4, the increased pressure exceeding a certain pressure is released to the pressure absorbing portion 4. As a result, excessive pressure is not applied to the product cavity 6, and “casting”, “shrinkage nest” (also referred to as shrinkage nest) and “seizure nest” can be prevented, and good cast iron casting Will be able to.

Comparative test for confirming the effect of the present invention The present invention uses the one shown in Example 2 above, and does not have a pressure absorbing portion (described as a comparative example in Tables 2 and 3 below). Compared with. The cast iron melts used here were cast in two types shown in the following Table 1 into 5 molds at 1370 ± 20 ° C., and after cooling sufficiently, each cast product 18 was equally shot blasted. went. When these cast products 18 were placed on the surface plate 19 and inspected, it was confirmed that there was a gentle convex deformation at the bottom of the cast products 18 (see FIG. 10).

Therefore, as shown in FIG. 11, each casting product 18 was measured with a thickness gauge at two locations indicated by Ta and Tb, and the total value (Ta to b) was obtained. The results are shown in Tables 2 and 3 below. The former is the result when the molten metal is FC-200, and the latter is the result when FCD-450 is used.

  As a result of the above, almost no deformation was observed in the products cast using the molds of the examples of the present invention, as shown in the upper part of each table. As shown in the lower part of each table, deformation was found in the lower part of the cast product 18. This deformation is a dimensional defect brought about by “molding”.

  In addition, in the mold 1 of the embodiment having the feeder part 2 of the present invention, it was confirmed that the partition wall 5 swelled upward and was broken in the feeder part 2 after casting, and the opening 17 was formed. This means that the pressure increase due to the molten metal was released to the pressure absorbing portion 4 and absorbed, and it was demonstrated that a good casting product 18 was cast.

  The present invention is good in cast iron casting using a sealed embedded feeder type, preventing deformation of a soft portion of a mold generated, preventing occurrence of a dimensional defect of a cast product 18, and suppressing occurrence of a “shrinkage nest”. When it is going to manufacture a simple casting product 17, it can utilize very effectively.

1-mold 2-feeder part 3-molten metal filling part 4-pressure absorption part 5-partition wall 6-product cavity part 7-mold frame 8-recessed part 9-recessed part 10-recessed part 11-semi-disc-like part 12-recessed groove 13 -Pouring gate 14-Runway 15-Sleeve 16-Notch 17-Opening 18-Casting product 19-Surface plate

Claims (5)

In the method using the vertical split mold 1 having the embedded feeder 2,
In the mold 1, the feeder part 2 that communicates with the product cavity part 6,
It is composed of a hollow molten metal filling portion 3 for exhibiting the original hot metal effect, and a hollow pressure absorbing portion 4 that is outside thereof and can absorb the increased pressure generated when the cast iron melt is solidified,
A partition wall 5 is provided between the molten metal filling portion 3 and the pressure absorbing portion 4 that can be deformed to the pressure absorbing portion 4 side with the increased pressure when the inside of the molten metal filling portion 3 exceeds a certain pressure,
When the cast iron melt is solidified, the increased pressure generated in the molten metal filling portion 3 is released to the pressure absorbing portion 4 that can be absorbed by the deformation of the partition wall 5, and cast iron is cast so that excessive pressure is not applied to the product cavity portion 6. A cast iron casting method characterized by the above. An embedded-type feeder 2 used for a vertically split mold 1,
A hollow molten metal filling portion 3 for demonstrating the original hot metal effect so as to communicate with the product cavity portion 6 by combining the molds 7 and 7 on both sides, and an increased pressure at the time of solidification of the molten cast iron on the upper portion thereof And a hollow pressure absorbing portion 4 capable of absorbing
A cast iron casting mold in which a partition wall 5 is provided between the molten metal filling portion 3 and the pressure absorbing portion 4 that can be deformed to the pressure absorbing portion 4 side by the increased pressure when the inside of the molten metal filling portion 3 exceeds a certain pressure. No hot water club. An embedded-type feeder 2 used for a vertically split mold 1,
The combination of the molds 7 and 7 on both sides is a hollow molten metal filling portion 3 for exerting the original hot metal effect so as to communicate with the product cavity portion 6, and an increased pressure at the time of solidification of the cast iron melt on the upper portion thereof A hollow pressure absorbing portion 4 capable of absorbing
When the former 3 exceeds a certain pressure due to solidification of the molten cast iron between the molten metal filling part 3 and the pressure absorbing part 4, the partition wall 5 made of foundry sand is deformable to the latter 4 side by the increased pressure. A hot metal part of a cast iron casting mold. A vertically split mold 1 having an embedded feeder 2,
A cast iron casting mold in which a vertically split mold is formed using the one according to claim 2 or the one according to claim 3 as the feeder part 2 there. In making vertical split molds by molding with a raw automatic molding machine,
Vertically-divided semi-cylindrical recesses 8, 8 that form hollow hollow metal-filled portions 3 for communicating with the product cavity portion 6 and exhibiting the original hot-water-feeding effect after being combined with the molds 7, 7 on each side, In the upper part, vertically divided semi-disc shaped portions 11 and 11 of casting sand that become the disc-shaped partition wall 5 after the union, and a hollow pressure absorbing portion 4 that can absorb the increased pressure at the time of solidification of the cast iron melt after the union Forming vertically divided semi-cylindrical recesses 9 and 9,
In addition, the partition wall 5 formed into a disk shape by the combination of the two molds 7 and 7 can be deformed to the upper pressure absorbing part 4 side with an increased pressure when the inside of the lower molten metal filling part 3 exceeds a certain pressure. A mold making method for cast iron casting is characterized in that the vertically split mold 1 is formed by forming the feeder part 2 as described above.

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