JP2012179617A - Molten metal-retaining furnace, and method for pouring molten metal in the furnace - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a molten metal-retaining furnace capable of preventing leakage of a molten metal without immersing a tapping hole in the molten metal, and to provide a method for pouring the molten metal in the furnace.SOLUTION: The molten metal-retaining furnace 20 comprises: a furnace body 21; an upper lid 27 opening when feeding the molten metal M to the furnace body 21 and closing the inside of the body 21 during closure; a porous member 51 provided to the tapping hole 22 of the body 21; and a pressure adjuster 40 for adjusting the pressure inside the body 21 during closure of the upper lid 27.

Description

  The present invention relates to a molten metal holding furnace in which a porous member is provided at a hot water outlet and a pouring method in the molten metal holding furnace.

Conventionally, in a bottom pouring-type molten metal holding furnace that discharges molten metal from a hot water outlet provided at the bottom of the furnace body, in order to open and close the hot water outlet, a sliding gate type with a sliding gate at the hot water outlet, There is a stopper nozzle type with a stopper. In these technologies, the nozzle that forms the pouring gate and the stopper or sliding gate are made of metal, and the pouring gate is sealed with a metal touch, so that the molten metal may leak.
In order to solve such problems, a porous member is provided at the outlet of the furnace body, the outlet of the furnace body is immersed in the molten metal, the pressure above the porous member is reduced, and the molten metal is introduced into the furnace body through the holes of the porous member. There has been proposed a molten metal holding furnace that sucks out and holds the molten metal in the furnace body and releases the molten metal through the holes of the porous member by releasing the air above the porous member (for example, see Patent Document 1).

Japanese Utility Model Publication No. 55-055256

However, in the above-described conventional configuration, since the outlet of the furnace body must be immersed in the molten metal, there is a risk that the outlet may be damaged due to the influence of heat or the like, particularly when cast iron that is at a high temperature is used as the material of the molten metal. is there.
The present invention has been made in view of the above-described circumstances, and an object thereof is to provide a molten metal holding furnace and a pouring method in the molten metal holding furnace that can prevent the leakage of the molten metal without immersing the outlet in the molten metal. To do.

In order to achieve the above-described object, the present invention provides a furnace body, an upper lid that is opened when supplying molten metal to the furnace body, and that seals the furnace body during closing, and a porous member that is provided at the outlet of the furnace body And pressure adjusting means for adjusting the pressure in the furnace body when the upper lid is closed.
According to the above configuration, since the porous member is provided at the outlet of the furnace body, it is not necessary to seal the outlet with a metal touch, so that leakage of the molten metal can be prevented. Further, since the pressure adjusting means for adjusting the pressure in the furnace body when the upper lid is closed is provided, the molten metal supplied to the furnace body is held when the upper lid is opened, and the furnace body is relatively moved by the pressure adjusting means when the upper lid is closed. Since the molten metal in the furnace can be discharged by pressurizing, it is not necessary to immerse the outlet in the molten metal, and damage to the outlet can be prevented.

The present invention also provides a furnace body for storing molten metal to be supplied to the mold, an upper lid that is opened when the molten metal stored in the furnace body is supplied to the furnace body, and that seals the furnace body during closing, and a tapping outlet for the furnace body And a pressure adjusting means for adjusting the pressure in the furnace and / or the mold when the upper lid is closed.
According to the above configuration, since the porous member is provided at the outlet of the furnace body, it is not necessary to seal the outlet with a metal touch, so that leakage of the molten metal can be prevented. Further, since the pressure adjusting means for adjusting the pressure in the furnace body and / or the mold when the upper lid is closed is provided, the molten metal supplied to the furnace body is held when the upper lid is opened, and the furnace is operated by the pressure adjusting means when the upper lid is closed. Since the molten metal in the furnace is poured into the mold by pressurizing the inside of the mold, it is not necessary to immerse the outlet in the molten metal, and damage to the outlet can be prevented.

The present invention is also a pouring method in a molten metal holding furnace for supplying molten metal stored in a furnace body to a mold through a hole in a porous member provided at a discharge port of the furnace body, and the molten metal is held in the furnace body The pressure inside the mold is the same as that in the mold or the pressure inside the mold is reduced with respect to the mold, and the pressure inside the mold is poured into the mold through the hole of the porous member. It is characterized by pouring hot water while maintaining the pressure higher than the pressure.
According to the above configuration, since the porous member is provided at the outlet of the furnace body, it is not necessary to seal the outlet with a metal touch, so that leakage of the molten metal can be prevented. While holding the molten metal in the furnace body, the pressure in the mold and the furnace body are the same or the pressure inside the furnace is reduced with respect to the mold, and the pressure in the furnace body is poured into the mold through the hole of the porous member. Since the hot water is poured while being kept at a pressure higher than the pressure, it is not necessary to immerse the hot water outlet in the molten metal, so that the hot water outlet can be prevented from being damaged.

  According to the present invention, since the porous member is provided at the outlet of the furnace body, it is not necessary to seal the outlet with a metal touch, so that leakage of the molten metal can be prevented. Further, since the pressure adjusting means for adjusting the pressure in the furnace body when the upper lid is closed is provided, the molten metal supplied to the furnace body is held when the upper lid is opened, and the furnace body is relatively moved by the pressure adjusting means when the upper lid is closed. Since the molten metal in the furnace body is discharged by pressurizing, it is not necessary to immerse the outlet in the molten metal, and damage to the outlet can be prevented.

  Further, since the porous member is provided at the outlet of the furnace body, it is not necessary to seal the outlet with a metal touch, so that leakage of the molten metal can be prevented. Further, since the pressure adjusting means for adjusting the pressure in the furnace body and / or the mold when the upper lid is closed is provided, the molten metal supplied to the furnace body is held when the upper lid is opened, and the furnace is operated by the pressure adjusting means when the upper lid is closed. Since the molten metal in the furnace is poured into the mold by pressurizing the inside of the mold, it is not necessary to immerse the outlet in the molten metal, and damage to the outlet can be prevented.

  Further, since the porous member is provided at the outlet of the furnace body, it is not necessary to seal the outlet with a metal touch, so that leakage of the molten metal can be prevented. While holding the molten metal in the furnace body, the pressure in the mold and the furnace body are the same or the pressure inside the furnace is reduced with respect to the mold, and the pressure in the furnace body is poured into the mold through the hole of the porous member. Since the hot water is poured while being kept at a pressure higher than the pressure, it is not necessary to immerse the hot water outlet in the molten metal, so that the hot water outlet can be prevented from being damaged.

It is a figure which shows typically the casting apparatus to which the molten metal holding furnace which concerns on the 1st Embodiment of this invention is applied. It is sectional drawing which expands and shows a porous member and its vicinity. It is a figure which shows the example of a porous member. It is a figure which shows typically the casting apparatus to which the molten metal holding furnace which concerns on the 2nd Embodiment of this invention is applied. It is sectional drawing which expands and shows a porous member and its vicinity.

Embodiments of the present invention will be described below with reference to the drawings.
<First Embodiment>
FIG. 1 is a diagram schematically showing a casting apparatus to which the molten metal holding furnace according to the first embodiment is applied.
The casting apparatus 1 is generally configured to include a mold 10 and a molten metal holding furnace 20. The mold 10 is a copper mold for casting two camshafts as an example of a casting, and the mold 10 is provided with a cooling means (not shown). The mold 10 includes a fixed mold 10A (for example, the lower half of the mold 10 in the direction perpendicular to the paper surface) and a movable mold 10B (for example, the upper half of the mold 10 in the direction of the paper surface), and the fixed mold 10A and the movable mold 10B can be opened and closed with respect to each other. Has been. FIG. 1 is a diagram showing the fixed mold 10A from the movable mold 10B side. The mold 10 includes a gate 11, a main runner 12, a sub runner 13, a choke 14, a filter 15, a gas vent hole 16, a gate 17, and a cavity 18 on the mating surface of the fixed mold 10 </ b> A and the movable mold 10 </ b> B. The configuration of the mold 10 is symmetrical with respect to the main runner 12.

  The gate 11 is, for example, an inlet for a molten metal M obtained by melting a cast iron material. The main runner 12 is a runner that supplies the molten metal M injected from the gate 11 to the left and right sub-runners 13. The sub runner 13 is a runner that supplies the molten metal M from the main runner 12 to the cavity 18. The choke 14 is a throttle portion that is provided on the inlet side of the sub-runner 13 and decelerates the flow rate of the molten metal M supplied to the sub-runner 13. The filter 15 is provided between the choke 14 and the gate 17 in the sub-runner 13 and removes gas and foreign matter in the molten metal M. The vent hole 16 is connected to the sub-runner 13 and discharges gas generated from the molten metal M. The gate 17 is provided on the outlet side of the sub-runner 13 and is connected to the cavity 18. One left and right gates 17 are provided corresponding to the number of cavities 18. The mold 10 is an open mold in which the upper part of the cavity 18 is opened.

The molten metal holding furnace 20 includes a furnace body 21 in which the molten metal M is stored. The top surface of the furnace body 21 is open, and a hot water outlet 22 is formed at the bottom of the furnace body 21. The hot water outlet 22 is provided substantially at the center of the furnace body 21. The molten metal M in the furnace body 21 is discharged from the hot water outlet 22 to the mold 10 as indicated by broken line arrows.
The side surface of the furnace body 21 is covered with an exterior body 24, and the top surfaces of the furnace body 21 and the exterior body 24 are closed by a removable maintenance lid 25. The maintenance lid 25 is provided with a sealing material (not shown) between the exterior body 24 so that the closed state of the furnace body 21 can be maintained.

  The maintenance lid 25 has a supply port 26 for supplying the molten metal M from the molten metal supply ladle 46 into the furnace body 21. The supply port 26 is provided at a position offset from the center of the furnace body 21 so as not to overlap the hot water outlet 22 vertically. The supply port 26 is provided with an openable / closable upper lid 27. The upper lid 27 is opened when the molten metal M is supplied to the furnace body 21, and is configured to seal the interior of the furnace body 21 during closing. . The upper lid 27 is provided with a leak valve 47.

  A pressure adjusting means 40 for adjusting the pressure in the furnace body 21 is connected to the maintenance lid 25. The pressure adjusting means 40 includes a pressurizing means 41 that pressurizes the inside of the furnace body 21 and a decompression means 42 that decompresses the inside of the furnace body 21. The pressure path 41A extending from the pressure means 41 and the pressure reduction path 42A extending from the pressure reduction means 42 merge to form a pressure path 40A, and the pressure path 40A is connected to the maintenance lid 25. The pressure path 40A passes through the maintenance lid 25 and communicates with the inside of the furnace body 21, and is connected to the maintenance lid 25 in an airtight manner by a sealing material (not shown).

  In the present embodiment, the furnace body 21 is formed with a housing part 50 in which the lower end of the tap 22 is enlarged, and the porous member 51 having a plurality of pores 52 (see FIG. 2) in the housing part 50. Is housed. The porous member 51 is supported from below by, for example, a plate-like fixing member 53. The fixing member 53 is formed with a through hole 53A smaller than the porous member 51. The fixing member 53 is fixed to the furnace body 21 with a fastening bolt or the like (not shown).

FIG. 2 is an enlarged cross-sectional view showing the porous member 51 and the vicinity thereof.
The porous member 51 is formed larger than the hot water outlet 22. The material of the porous member 51 is determined by the component of the molten metal M, the temperature of the molten metal M, the wettability with the molten metal M, etc. For example, ceramic such as mullite, alumina, silicate, or graphite is used. The size of the pore 52 is set to a size that prevents the molten metal M from passing through the pore 52 only by the melt surface tension of the molten metal M even when the weight of the molten metal M is applied to the porous member 51. Therefore, the size of the pore 52 is determined by the pressure (arrow A) depending on the depth of the molten metal M held in the furnace body 21, the pressure difference between the top and bottom of the porous member 51, that is, the pressure inside the furnace body 21 (arrow B) And the pressure outside the molten metal holding furnace 20 (arrow C), the surface tension of the molten metal M (arrow D), etc., for example, the diameter is set to about 0.5 to 1 mm.

FIG. 3 is a diagram illustrating an example of the porous member 51.
The pores 52 of the porous member 51 are formed in various shapes. The porous member 51 may be, for example, a porous member 51A in which the pores 52 are formed as linear round holes as shown in FIG. 3 (A), or as shown in FIG. 3 (B). In addition, the pore 52 may be a porous member 51B formed in a three-dimensional structure in which substantially spherical spaces are connected. As shown in FIG. The porous member 51C formed in the hole may be used. When the pore 52 is a linear round hole, the diameter of the pore 52 is preferably about 0.8 mm.

Next, the operation of the present embodiment will be described.
First, the fixed mold 10 </ b> A and the movable mold 10 </ b> B of the mold 10 are clamped, and the molten metal holding furnace 20 is disposed above the mold 10 so that the pouring gate 22 faces the pouring gate 11. The molten metal supply ladle 46 in which the molten metal M is stored is conveyed directly above the molten metal holding furnace 20, and the molten metal M in the molten metal supply ladle 46 is supplied into the furnace body 21 from the supply port 26 with the upper lid 27 opened. Here, since the supply port 26 is provided at a position that does not overlap the hot water outlet 22 vertically, the molten metal M is not directly applied to the porous member 51 when the molten metal M is supplied into the furnace body 21. The molten metal M is prevented from leaking from the porous member 51 inside.
Using a porous member 51 having seven pores 52 having a diameter of 0.5 to 1.0 mm, a molten M8 kg of malleable cast iron is supplied to the furnace body 21, and the upper and lower sides of the porous member 51 at 1500 ° C. for 1 hour. As a result of conducting an experiment of maintaining the pressure at atmospheric pressure, the molten metal M did not leak from the porous member 51.

  When the supply of the molten metal M for one time is finished, the upper lid 27 is closed, and the inside of the sealed furnace body 21 is pressurized by the pressurizing means 41. Here, by opening the leak valve 47 from when the upper lid 27 is closed until the pressurization by the pressurizing means 41 is started, the pressurizing means 41 does not cause a pressure difference between the upper and lower sides of the porous member 51. The molten metal M can be held until pressurization is started. When the inside of the furnace body 21 is pressurized, the molten metal M in the furnace body 21 passes through the pores 52 of the porous member 51 due to a pressure difference between the inside of the furnace body 21 and the outside and gravity, and is indicated by a dashed arrow. The mold 10 is poured smoothly into the mold 10.

  As described above, since the porous member 51 is provided at the hot water outlet 22 and the pressurizing means 41 for pressurizing the hot water inside the furnace body 21 is provided, leakage of the molten metal M is prevented without the hot water outlet 22 being immersed in the molten metal M. it can. Further, since the hot water is discharged by pressurizing the inside of the furnace body 21 by the pressurizing means 41, the hot water discharge speed of the molten metal M can be easily adjusted. For example, when the hot water is poor in the mold 10, the pressure is increased. The hot water supply can be improved by increasing the hot water discharge speed.

  In the conventional equipment that immerses the outlet of the molten metal holding furnace in the molten metal and sucks the molten metal by reducing the pressure inside the molten metal holding furnace, the upper lid of the molten metal holding furnace must be closed while the molten metal is held, and the molten metal is opened by opening the upper lid. Although supply and adjustment of the molten metal are not possible, in the present embodiment, it is not necessary to reduce the pressure during the holding of the molten metal M, and the molten metal M can be held at atmospheric pressure. It is possible to add. Further, in the conventional apparatus that sucks the molten metal by reducing the pressure inside the molten metal holding furnace, the molten metal cannot be held if there is any gap in the molten metal holding furnace. However, the molten metal holding furnace 20 of the present embodiment does not hold the molten metal at atmospheric pressure. Therefore, the molten metal M can be held even if there is a slight gap in the molten metal holding furnace 20.

Since the porous member 51 is provided in the hot water outlet 22, foreign matters in the molten metal M are removed, so that the life of the mold 10 can be improved and the amount of hot water discharged due to clogging of the mold 10 and the inability to discharge hot water can be prevented. Moreover, since the flow of the molten metal M is rectified by the porous member 51, it is possible to reduce air entrainment defects generated in the cast product.
The porous member 51 provided in the hot water outlet 22 is replaced every time hot water is discharged. The porous member 51 is replaced by opening the upper cover 27 and removing the fixing member 53 when supplying the molten metal M to the furnace body 21. As described above, since the porous member 51 is replaced every time when the hot water is discharged, the porous member 51 can be used many times, and the porous plate can be prevented from being clogged by foreign matters in the molten metal M.

  As described above, according to the present embodiment, since the porous member 51 is provided at the hot water outlet 22 of the furnace body 21, it is not necessary to seal the hot water outlet 22 with a metal touch, thus preventing leakage of the molten metal M. it can. Further, since the pressure adjusting means 40 for adjusting the pressure in the furnace body 21 when the upper lid 27 is closed is provided, the molten metal M supplied to the furnace body 21 is held when the upper lid 27 is opened, and the pressure is adjusted when the upper lid 27 is closed. Since the molten metal M in the furnace body 21 can be discharged by pressurizing the interior of the furnace body 21 relative to the mold 10 by means 40, it is not necessary to immerse the outlet 22 in the molten metal M, and the damage to the outlet 22 is prevented. it can.

  In the present embodiment, the inside of the furnace body 21 is pressurized as it is after the molten metal M is supplied into the furnace body 21, but after the molten metal M is supplied into the furnace body 21, the gas in the furnace body 21 is replaced. You may pressurize from. In this case, after the supply of the molten metal M for one time is completed and the upper lid 27 is closed, the air in the sealed furnace body 21 is sucked by the decompression means 42 and the inside of the furnace body 21 is decompressed. Next, a predetermined type of gas is injected into the furnace body 21 by the pressurizing means 41 to pressurize the furnace body 21. The molten metal M in the furnace body 21 is smoothly poured into the mold 10 through the pores 52 of the porous member 51 due to the pressure difference between the furnace body 21 and the mold 10. In addition, when not replacing the gas in the furnace body 21, the decompression means 42 does not need to be provided.

<Second Embodiment>
Next, a second embodiment of the present invention will be described.
In the casting apparatus 1 shown in FIG. 1, the pressure inside the molten metal holding furnace 20 is adjusted. However, in the casting apparatus 100 of the second embodiment shown in FIG. 4, the molten metal holding furnace 120 is brought into close contact with the mold 110. Both 120 and mold 110 are pressure adjusted. In FIG. 4, the same parts as those of the casting apparatus 1 shown in FIG.

  The mold 110 is a sealed mold in which the cavity 18 is sealed, and has the same configuration as the mold 10 shown in FIG. 1 except that the cavity 18 is sealed. The furnace body 21 is disposed on the mold 110 such that the pouring gate 22 faces the pouring gate 11 of the mold 110. A sealing member 45 is provided between the mold 10 and the furnace body 21 so as to surround the gate 11 and the outlet 22, and the inside of the mold 10 and the furnace body 21 are sealed. The seal member 45 is made of, for example, silicon rubber. A pressurizing means 41 and a decompression means 42 of a pressure adjusting means 40 connected to the furnace body 21 are connected to the mold 110 so that the interior of the mold 110 is pressurized or depressurized. The pressurizing path 41B extending from the pressurizing means 41 and the decompressing path 42B extending from the decompressing means 42 merge to form a pressure path 40B, and the pressure path 40B is connected to the mold 110.

FIG. 5 is an enlarged cross-sectional view showing the porous member 51 and the vicinity thereof.
In the present embodiment, the furnace body 21 is formed with a cylindrical portion 150 protruding in a cylindrical shape so as to surround the accommodating portion 50, and the cylindrical portion 150 is fixed to a bottomed cylindrical shape having a bottom portion 153 </ b> B at one end. The member 153 is externally fitted. A through hole 153 </ b> A smaller than the porous member 51 is formed in the bottom 153 </ b> B of the fixing member 153. A screw part 150 </ b> A is formed on the outer periphery of the cylindrical part 150, and a screw part 153 </ b> C is formed on the inner periphery of the fixing member 153, and the screw part 153 </ b> C of the fixing member 153 is the screw part of the cylindrical part 150. It is fixed to the furnace body 21 by being screwed to 150A. When the fixing member 153 is fixed to the furnace body 21, the end surface 153D of the fixing member 153 is positioned on the same plane as the lower surface 21A of the furnace body 21 or above the lower surface 21A of the furnace body 21.

Next, the operation of the present embodiment will be described.
First, the fixed mold 10A and the movable mold 10B are clamped. The sealing member 45 is disposed on the mold 110 so as to surround the gate 11, and the furnace body 21 is disposed on the mold 110 so that the outlet 22 faces the gate 11. 10 adheres closely. Note that the seal member 45 is desirably disposed outside the fixing member 153. In the molten metal holding furnace 120, the molten metal M is supplied into the furnace body 21 from the supply port 26 with the upper lid 27 opened.

  When the supply of the molten metal M for one time is completed, the upper lid 27 is closed, the inside of the sealed furnace body 21 is pressurized by the pressurizing means 41, or the inside of the mold 110 is decompressed by the decompressing means 42, or both. Is done. If the inside of the mold 10 is not depressurized, a pressure difference is created between the upper and lower surfaces of the porous member 51 by opening the leak valve 47 from when the upper lid 27 is closed until pressurization by the pressurizing means 41 is started. Instead, the molten metal M can be held until pressurization by the pressurizing means 41 is started. The molten metal M in the furnace body 21 is smoothly poured into the mold 110 through the pores 52 of the porous member 51 due to the pressure difference between the inside of the furnace body 21 and the outside.

Using a porous member 51 having seven pores 52 having a diameter of 0.5 to 1.0 mm, a molten M8 kg of malleable cast iron is supplied to the furnace body 21 and the inside of the mold body 110 is pressurized by pressurizing the inside of the furnace body 21. As a result of an experiment to reduce the pressure, hot water was confirmed when the upper side of the porous member 51 was +1 atm and the lower side was −0.4 atm.
As described above, since the porous member 51 is provided at the pouring gate 22 and the pressure adjusting means 40 is provided to pressurize the inside of the furnace body 21 relative to the mold 110 and pour out the hot water, the pouring gate 22 is immersed in the molten metal M. Therefore, leakage of the molten metal M can be prevented. Further, since the hot water is discharged by pressurizing the inside of the furnace body 21 by the pressurizing means 41, the hot water discharge speed of the molten metal M can be easily adjusted. For example, when the hot water is poor in the mold 110, the pressure is increased. The hot water supply can be improved by increasing the hot water discharge speed.

  As described above, according to the present embodiment, since the porous member 51 is provided at the hot water outlet 22 of the furnace body 21, it is not necessary to seal the hot water outlet 22 with a metal touch, thus preventing leakage of the molten metal M. it can. Further, since the pressure adjusting means 40 for adjusting the pressure in the furnace body 21 and / or the mold 110 when the upper lid 27 is closed is provided, the molten metal M supplied to the furnace body 21 when the upper lid 27 is opened is held, and the upper lid Since the molten metal M in the furnace body 21 is poured into the mold 110 by pressurizing the interior of the furnace body 21 with respect to the mold 110 by the pressure adjusting means 40 when the block 27 is closed, the outlet 22 is not immersed in the molten metal M. In addition, damage to the hot water outlet 22 can be prevented.

  In the present embodiment, the inside of the furnace body 21 is pressurized as it is after the molten metal M is supplied into the furnace body 21, but after the molten metal M is supplied into the furnace body 21, the gas in the furnace body 21 and the mold 110 is changed. You may pressurize after replacing. In this case, after the supply of the molten metal M for one time is completed and the upper lid 27 is closed, the air in the sealed furnace body 21 is sucked by the decompression means 42 and the inside of the furnace body 21 is decompressed. Next, a predetermined type of gas is injected into the furnace body 21 by the pressurizing means 41 to pressurize the interior of the furnace body 21. If necessary, the inside of the mold 110 is decompressed by the decompression means 42. The molten metal M in the furnace body 21 is smoothly poured into the mold 110 through the pores 52 of the porous member 51 due to the pressure difference between the furnace body 21 and the mold 110. Note that when the gas in the furnace body 21 is replaced, the gas in the mold 110 may also be replaced. In this case, the atmospheric pressure in the furnace body 21 should not be higher than the atmospheric pressure in the mold 110.

However, the above embodiment is an aspect of the present invention, and it is needless to say that the embodiment can be appropriately changed without departing from the gist of the present invention.
For example, in the above-described embodiment, the porous member 51 is fixed to the hot water outlet 22 by the fixing member 53 and the screw-type fixing member 153 addressed from below, but the fixing method of the porous member 51 is as follows. It is not limited to this.

DESCRIPTION OF SYMBOLS 10,110 Mold 20,120 Molten holding furnace 21 Furnace body 22 Outlet 30 Pressure adjusting means 51 Porous member M Molten metal

Claims (3)

  The furnace body, an upper lid that is opened when supplying molten metal to the furnace body and is closed and the furnace body is hermetically sealed, a porous member provided at the outlet of the furnace body, and the pressure in the furnace body when the upper lid is closed A molten metal holding furnace comprising pressure adjusting means for adjusting.   A furnace body that stores molten metal to be supplied to the mold, an upper lid that opens when the molten metal stored in the furnace body is supplied to the furnace body, and seals the furnace body during closing, and a porous member provided at the outlet of the furnace body And a pressure adjusting means for adjusting the pressure in the furnace and / or the mold when the upper lid is closed. A pouring method in a molten metal holding furnace that supplies molten metal stored in a furnace body to a mold through a hole of a porous member provided at a discharge port of the furnace body,
While holding the molten metal in the furnace body, the pressure in the mold and the furnace body is the same or the pressure in the furnace body is reduced with respect to the mold, and the furnace is being poured into the mold through the hole of the porous member. A pouring method in a molten metal holding furnace, wherein pouring is performed while maintaining the pressure in the body higher than the pressure in the mold.

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