JPH0890204A - Method and apparatus for reduced pressure suction and pressurizing casting - Google Patents

Abstract

PURPOSE: To restrain bubbling of gas in molten metal and to obtain a casting apparatus for casting a cast product having complicated and thin shapes in the high quality by forming a suction hole on the surface of a mold near the last filling part of molten metal being apart from a runner in a product cavity and/or a feeder head and sucking and pressurizing through the suction hole. CONSTITUTION: A molten metal introducing part 5 in a mold 4 is dipped into the molten metal 15 in a molten metal holding furnace 14. At the time of sensing the dipping of the molten metal introducing part 5 with a molten metal surface sensor 19 fitted to the side surface of a reduced pressure vessel 2, the descent of the reduced pressure vessel 2 is stopped and the pressure reduction is started by actuating a pressure reducing device 12 after waiting the melting near the molten metal introducing part 5 at the bottom of a protecting frame 24. Since the air in the product cavity is sucked by reducing the pressure, the molten metal flowed into the runner 6 is quickly filled in the product cavity 7. After quickly completing the fill-up of the molten metal, the molten metal introducing part 5 of the mold 4 is drawn up from the molten metal 15 in the molten metal holding furnace 14. After closing the opening hole of the reduced pressure vessel 2 with a closed vessel the pressurizing is started by working a pressurizing device 14.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vacuum suction pressurizing casting apparatus and method, and in particular to castings such as cast steels and castings having complicated shapes and thin walls, which are inferior in castability, have high shrinkability, and are susceptible to gas defects. The present invention relates to a vacuum suction pressurizing casting apparatus and method suitable for manufacturing.

[0002]

2. Description of the Related Art Generally, when casting a thin casting having a thin portion of 5 mm or less, contact with the mold accelerates cooling and solidification of the molten metal, which deteriorates the fluidity of the molten metal. Defects such as defective bathing are likely to occur. Further, since shrinkage of molten metal occurs during solidification, shrinkage cavities and crack defects are likely to occur. Although these casting defects are dealt with by a feeder, a feeder of an appropriate size is required to obtain an appropriate feeder force, and in order to promote directional solidification, a feeder is required. It is known to provide a core (generally called "Williams core") that forms a hotspot part by making the tip part of the tongue into a convex shape and adds atmospheric pressure from that part. This Williams core delays solidification by making it into a shape that is easily heat-saturated, and acts on the molten metal with the pressure required to replenish the molten metal during the solidification process. However, it is difficult to stably and effectively apply the atmospheric pressure to the Williams core.
Molten metal easily absorbs gas from the air and remains as a gas defect in the cast product after solidification, which becomes a problem.

The lost wax casting method is known as one of the methods for producing a thin casting having a complicated shape.
In this lost wax casting method, a ceramic mold is used, and the mold is heated to 700 ° C. to 900 ° C. at the time of casting to slow the cooling rate of the molten metal during filling and improve the fluidity of the molten metal. However, since an expensive ceramic mold is used, it is expensive to mold the mold, and the manufacturing cost is considerably high for casting a thin casting having a complicated shape.

There is a low-pressure casting method as a casting method in which the casting speed is relatively easy to control. However, since the back pressure of the unfilled portion of the cavity increases during casting, the thin-walled casting or the casting having a complicated shape has a poor hot-water flowability. Become.

[0005]

Further, as a casting method for thin-walled castings, Japanese Patent Publication No. 60-35227 discloses a vacuum suction casting method in which the cavity in the mold is depressurized and the molten metal is suction-cast in the cavity of the mold. And has been used recently. However, Japanese Patent Publication No. 60-35227 discloses that air is apt to be entrained from the mold portion which is not immersed in the molten metal, and the effect of vacuum suction is insufficient. Further, although a product having a small height and a simple shape can be cast, it is difficult to apply it to a casting having a complicated shape because of its height and a thick portion. Further, since the high-vacuum state is maintained, the pressure of the molten metal is likely to decrease to form a bubble state, which remains as a gas defect after solidification, and it is difficult to obtain a sound cast product. Further, in the vacuum suction casting, the molten metal that has been completely filled is held in a high vacuum state, so that there is a drawback in that it is not possible to apply a feeder force using the above-mentioned William core.

As a casting method for obtaining a thin cast product, Japanese Patent Laid-Open Publication No.
In the method of filling the mold with the molten metal, the pressure of the molten metal is applied to the mold to suck the molten metal, and after the molten metal is filled, the molten metal surface of the molten metal is pressurized to form the molten metal. There is a disclosure of a suction pressure casting method for applying a pressing force.

However, JP-A-62-114761
In the publication, there is a limit to the pressurization of the casting product part through the molten metal. That is, generally, the solidification form of metal is dendrite growth, but pressure loss occurs in the molten metal between dendrites, and it is impossible to exert a uniform pressurizing effect on the product portion through the molten metal. Therefore, although the molten metal feeder effect can be obtained in the portion close to the molten metal surface, the product portion and the feeder are often separated from the molten metal surface, and it is difficult to obtain the effect.

As described above, in the conventional casting technique, it is difficult to rapidly fill the product cavity and the feeder with the molten metal and to exert the feeder effect during solidification. An object of the present invention is to solve the above-mentioned problems of the conventional casting technique and to rapidly fill a product cavity and a feeder with molten metal,
An object of the present invention is to provide a vacuum suction pressurizing casting method and an apparatus therefor which are suitable for producing a casting effect during solidification and casting a casting having a thin wall thickness of 5 mm or less and a complicated shape without defects. It was difficult.

[0009]

As a result of earnest research in view of the above object, the present inventors have found that a suction effect is provided by providing a suction port in the vicinity of a product cavity of a mold placed in a depressurized container and a feeder. And the pressurizing effect is remarkably enhanced, gas bubbles in the molten metal are reduced or eliminated, directional solidification of the riser is promoted, shrinkage cavities and cutting defects are minimized, and thin wall castings with complex shapes are cast. The present invention has been accomplished by finding that it can be manufactured without defects and at low cost.

That is, the vacuum suction pressure casting method of the present invention is
A reduced pressure suction pressure casting method of pouring molten metal into a mold by vacuum suction and pressurizing the molten metal at least while solidification is completed, comprising: (a) a runner and a product cavity communicating with the runner; Preparing a mold having a feeder communicating with the product cavity, and forming a suction port on the mold surface near the final filling portion of the molten metal away from the runner in the product cavity and / or the feeder; (B) a step of disposing the mold so that the runner of the mold is opened in an opening of a decompression container having at least one opening at the bottom, (c) after immersing the runner in a molten metal, A step of reducing the pressure in the mold through the suction port by a pressure reducing device attached to the pressure reducing container to rapidly fill the product cavity and the riser with the molten metal; (d)
By the sealing member having at least one or more openings,
A step of sealing the opening of the decompression container, (d) a step of pressurizing the product cavity and the feeder with the pressurizing device attached to the decompression container through the suction port, and a combination of the above steps. Is characterized by.

A porous member made of a material having better air permeability than the other parts of the mold is provided in a portion of the suction port which is close to the product cavity and / or the feeder. In addition, a suction port is provided in the vicinity of the final filling portion and / or the final solidification portion of the molten metal of the feeder to make the distance between the mold surface and the feeder smaller than other portions. Furthermore,
Before depressurizing, the inside of the depressurizing vessel is replaced with an inert gas. Furthermore, the pressure in the decompression container is increased with an inert gas.

Next, the vacuum suction pressure casting apparatus of the present invention is
A reduced pressure suction pressure casting apparatus for pouring molten metal into a mold by reduced pressure suction and pressurizing the molten metal at least until completion of solidification, comprising: (a) a reduced pressure container having at least one or more openings in a bottom portion; , (A) has a runner, a product cavity that communicates with the runner, and a feeder that communicates with the product cavity, the A mold in which a suction port is formed on the surface of the mold near the final filling portion of the molten metal away from the runner, and the runner opens from the opening of the pressure reducing container; and (c) the runner is immersed in the molten metal. After that, a decompression device attached to the decompression container for decompressing through the suction port to rapidly fill the molten metal into the product cavity and the riser, and (d) at least one or more openings. Having the above decompression It is characterized by comprising a sealing member for sealing the opening of the container, and (d) a pressurizing device attached to the decompression container for pressurizing the product cavity and the feeder through the suction port.

The mold has a porous member, which is made of a material having better air permeability than the other parts of the mold, in a portion of the suction port near the product cavity and / or the feeder. Further, in the mold, a suction port is formed in the vicinity of the final filling portion and / or the final solidification portion of the molten metal of the feeder to make the distance between the mold surface and the feeder smaller than other portions. Furthermore, the decompression device has a means for replacing the inside of the decompression container with an inert gas before decompression. Furthermore, the pressurizing device has a pressurizing means for applying an inert gas in a decompression container.

The vacuum suction pressurizing casting method and apparatus of the present invention is preferably used for cast steel or the like, which has a high melt temperature, has a complicated shape and is thin, and is difficult to manufacture. Such cast steel has high heat resistance and oxidation resistance. Further, it is also preferably used for low alloy cast steel or the like, which has a high melt temperature, solidification shrinkage ratio, and gas component content in the molten metal and is difficult to manufacture a thin casting. Such cast steel has high mechanical properties, and one example of its composition is as follows. C
: 0.05 to 0.45% by weight, Si: 0.4 to 2% by weight, Mn: 0.3 to 1% by weight, Cr: 16 to 25% by weight, W: 0 to 3% by weight, Ni: 0. ~ 2 wt%, Nb
And / or V: 0.01 to 1% by weight, balance: Fe and unavoidable impurities. The cast steel having the above composition is a phase (α phase + carbide) transformed from the γ phase in addition to the usual α phase, and α ′ phase. Has a phase called. The area ratio of the α ′ phase to the (α phase + α ′ phase) is preferably 20 to 90%.

[Action]

When the pressure inside the pressure reducing container is reduced by the pressure reducing device by the mold having the suction port formed on the surface of the mold near the final filling portion of the molten metal in the product cavity and / or feeder, which is far from the runner, the product is discharged from the suction port. By rapidly filling the cavity and feeder with molten metal and pressurizing the decompression container with a pressure device, gas bubbles in the molten metal in the product cavity and feeder through the suction port are reduced or eliminated, Furthermore, the heat saturation of the mold part between the feeder and the mold surface (the state where heat dissipation is saturated) becomes faster, which delays the solidification of the feeder near the suction port and increases the feeder force into the product cavity. Give.

Further, if a porous member made of a material having better air permeability than the other parts of the mold is provided in a portion of the suction port, which is close to the product cavity and / or the feeder, the molten metal can be more rapidly melted. As a result, the molten metal is sufficiently filled in the product cavity even with a casting having a complicated shape and a thin wall, and the feeder effect is further improved. If the inside of the decompression container is replaced with an inert gas before depressurization, and / or the pressurization inside the decompression container is performed with an inert gas, the metal melt is less oxidized,
High quality castings with excellent mechanical properties can be cast.

Next, the generation mechanism of gas defects, shrinkage cavities, crack defects, etc. will be described in detail with reference to the drawings. Figure 5
FIG. 3 is a diagram schematically showing a molten metal replenishment mechanism that largely influences generation of various defects, a pressure distribution, and a generation mechanism of porosity that is a starting point of defects. FIG. 5 (A) shows flow replenishment between dendrites and liquid phase replenishment while the molten metal is solidifying, and FIG. 5 (B) shows porosity generation conditions, where the horizontal axis is the distance from the molten metal injection port, The vertical axis is the pressure applied between the dendrites.

In the case of ordinary casting, since the unsolidified region is large at the initial stage of solidification, the liquid phase replenishment is dominant as shown in FIG. At this time, the molten metal pressure (P) does not decrease so much and is sufficiently higher than the bubble formation pressure (Pg) of the gas dissolved in the molten metal, so that porosity is not generated. However, when the solidification progresses from the middle stage to the final stage, the solidification progresses, and the molten metal supply shifts to the inter-dendritic flow supply. At this time, the molten metal pressure P decreases due to the flow resistance between the dendrites, whereas the gas dissolved in the molten metal in the unsolidified portion is concentrated and the bubbling pressure (Pg) rises. Then, when the molten metal pressure (P) and the bubbling pressure (Pg) are reversed, porosity occurs.

As shown in FIG. 1B, the porosity is generated by reversing the bubbling pressure Pg even when the molten metal pressure P is applied to the molten metal by applying a specific pressure to the molten metal. It can be prevented by not allowing it. FIG. 3 is a conceptual diagram for explaining the effect of pressurization. By directly pressurizing the molten metal for a long time, it is possible to suppress gas bubbles in the molten metal.
Further, since the suction port 18 and the feeder 8a are close to each other, the heat saturated portion 8b is generated. Therefore, in the part of the feeder 8a near the suction port 18, the unsolidified portion 8c in which solidification is relatively delayed
Occurs. The rate of solidification in the feeder 8a depends on the suction port 18 and the feeder 8
It can be controlled by appropriately adjusting the distance from a. Since the inside of the decompression container 2 is pressurized, the suction port 18
The pressurizing effect from the unsolidified portion of the molten metal is rapidly increased by being pressurized into the feeder 8a through the, and lasts for a long time. The pressurizing effect in the feeder 8a can be controlled by appropriately adjusting the distance between the suction port 18 and the feeder 8a.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The vacuum suction pressurizing casting apparatus and method of the present invention will be described in detail below with reference to the drawings. (Embodiment 1) FIG. 1 is a schematic sectional view showing a vacuum suction casting apparatus according to an embodiment of the present invention. The vacuum suction pressurizing casting apparatus 1 of the present invention includes a vacuum container 2 having an opening at the bottom.
Mold 4 having product cavity 7, runner 6, riser 8a, etc.
Is provided, a vacuum suction force is applied to the vacuum container 2 from above, the molten metal 15 is sucked from the molten metal introduction part 5 at the lower end of the mold 4, and the molten metal 15 is poured into the product cavity 7 and the feeder 8a. Immediately after the filling is completed, as shown in FIG. 2, the opening of the decompression container 2 is closed with a closed container 17, and the inside of the decompression container 2 is pressurized to be solidified in a pressurized state. Specifically, the vacuum suction pressurization casting apparatus 1 includes a vacuum container (for example,
An iron decompression container 2 having an inner diameter of 600 mm and a height of 800 mm 2 is provided, and an opening 3 is provided at the bottom of the decompression container 2. Further, the lid member 2a is engaged with the upper portion of the decompression container 2 in a sealed state, and the decompression flexible pipe 9 and the pressure flexible pipe 10 are attached to the upper end portion of the lid member 2a. The decompression flexible pipe 9 is composed of decompression control means 11
Is connected to the pressure reducing device 12 such as a vacuum pump. The pressure flexible tube 10 is connected to a pressure device 14 such as a pressure tank via a pressure control means 13.

A sand mold 4 is housed in the decompression container 2. In this embodiment, a sand mold using silica sand or the like is suitable from the viewpoint of moldability and air permeability. For example, a cold box mold made from silica sand No. 7 is preferable. The sand mold 4 is provided with a molten metal introducing portion 5 which projects downward from the lower surface of the sand mold, and the sand casting mold 4 is arranged in the decompression container 2 so that the molten metal introducing portion 5 projects downward from the opening 3. It

In the sand mold 4, a runner 6 (for example, a vertical 20
mm having a cross section of 30 mm and a width of 30 mm) extends vertically from the molten metal introducing portion 5, and the runner 6 communicates with a product cavity 7. As the product cavity 7, for example, the outer diameter 6
0 mm, length 200 mm, wall thickness 2.5 mm pipe section 7
Examples of the shape include a, a flange portion 7b having an outer diameter of 80 mm and a width of 3 mm, and a boss portion 7c having an outer diameter of 10 mm and a diameter of 20 mm protruding from the pipe portion, but the shape is not limited to this. It is preferable that the inner surface of the product cavity 7 is coated with a coating agent in a thickness of 0.01 to 0.4 mm, for example, 0.15 mm. At the upper end of the product cavity 7, a feeder 8a (also serving as a spout) and a weir 8b are provided. The decompression container 2, the lid member 2a, and the mold 4
Packing 23 is disposed between the mold 4 and the mold 4 to prevent the sealed state of the decompression container 2 from being deteriorated.
It also prevents the degree of pressure reduction of the product cavity 7 from decreasing.

On the upper surface of the mold 4 facing the pressure reducing side, there is formed a suction port 18 cut into a concave shape toward the feeder 8a of the product cavity 7. The suction port 18 is preferably close to the feeder 8a to the extent that the molding sand interposed between the feeder 8a and the feeder 8a is not crushed by mechanical or thermal shock during casting. Specifically, from the bottom of the suction port 18 the feeder 8a
The distance to is preferably about 15 to 30 mm. Further, the diameter of the suction port 18 is not particularly limited as long as the mechanical strength of the mold 4 does not decrease, and can be appropriately set according to the sizes of the product cavity 7 and the feeder 8a. As a specific example, the diameter of the suction port 18 can be about 50 mm. On the outer side surface of the decompression container 2, a melt level sensor-19 for detecting that the decompression suction pressurizing casting apparatus 1 is immersed in the melt 15 in the melt holding furnace 14 is attached.

When casting is carried out by the vacuum suction pressurizing casting apparatus 1 of FIG. 1, first, the molten metal introduction part 5 of the mold 4 is placed in the molten metal holding furnace 1.
It is dipped in the molten metal 15 in 4. When the melt level sensor 19 attached to the side surface of the decompression container 2 senses the immersion of the molten metal introducing part 5, the descent of the decompression container 2 is stopped and the vicinity of the molten metal introducing part 5 at the bottom of the protective frame 24 is melted. After waiting, the decompression device 11 is activated to start decompression. When the pressure in the decompression container 2 is reduced, the air in the product cavity 7 is sucked through the suction port 18, so that the molten metal that has entered the runner 6 is rapidly filled in the product cavity 7. The degree of pressure reduction in the product cavity 7 can be controlled by appropriately adjusting the distance between the suction port 18 and the riser 8a.

After the molten metal is rapidly filled, the mold 4
The molten metal introduction part 5 is pulled up from the molten metal 15 in the molten metal holding furnace 14. At this time, the unsolidified portion of the runner 6 is the molten metal holding furnace 1
4, the molten metal in the product cavity 7 is sized so that the weir immediately solidifies so as not to flow down. After closing the opening 3 of the decompression container 2 with the closed container 17, the pressurizing device 13 is operated to start pressurization.

(Embodiment 2) FIG. 4 is a schematic cross-sectional view showing another embodiment of the vacuum suction pressurizing casting apparatus shown in FIGS. 1 and 2. The basic structure is the vacuum suction pressurizing casting shown in FIG. Same as the device. Therefore, the same members as those in FIGS. 1 and 2 are denoted by the same reference numerals. In FIG. 4, a porous member 16 having an air permeability higher than that of the mold 4 main body is provided between the suction port 18 and the molten metal 8a as the molten metal final filling portion.
It is preferable that the porous member 16 is formed by solidifying, for example, a disk-shaped or flat-plate-shaped casting sand having a grain size smaller than that of the mold.
The porous member 16 may be integrally embedded in the mold 4 at the time of molding, but it may be formed as a separate body and used by being fitted into the mold 4 at the time of casting.

The air permeability between the mold 4 and the porous member 16 is effective if the latter is larger than the former, but the latter is preferably about 3 to 30 times as large as the former. As an example of this air permeability, for example, the mold is silica sand No. 6 and the air permeability is 26.
1. Porous member 16 made of silica sand No. 5 with air permeability of 785, mold as zircon with air permeability of 48, porous member 1
It is preferable that 6 is silica sand No. 4 and the air permeability is 1130. However, the air permeability is (JIS) Z2603-1976
It is measured by "a method for testing air permeability of foundry sand".

Further, in this embodiment, an inert gas supply means 25 (not shown) is connected to the pressurizing device 14. The inert gas supply means 25 pressurizes an inert gas into the decompression container 2, purges the air in the decompression container 2 and replaces it with the inert gas. Nitrogen gas, argon gas and the like are preferable as the inert gas.

The operation of the vacuum suction pressurizing casting apparatus shown in FIG. 4 is performed by first replacing the atmosphere in the vacuum container 2 with an inert gas. For that purpose, first, the decompression device 12 is operated to purge the air in the decompression container 2, and the inert gas supply means 25 is supplied.
And the pressurizing device 14 is operated to fill the inside of the decompression container 2 with the inert gas. Then, the decompression container 2 containing the mold 4
Is lowered to immerse the molten metal introduction part 5 in the molten metal 15 in the molten metal holding furnace 14, and after the bottom of the protective frame 24 is melted, the pressure is reduced to suck the molten metal.

(Example 3) Using molten metal of cast steel (1560 ° C.) having the composition shown in Table 1 below, a casting experiment was conducted under various conditions by the vacuum suction pressurizing casting apparatus shown in FIG. As shown in FIG. 6, when the pressurization during solidification was properly selected according to the nitrogen (N) level in the molten metal, the molten metal was rapidly filled in the product cavity and the feeder, and the product cavity was pressed. The effect of hot water is also high, and it does not turn up to a wall thickness of 2.0 mm,
Those without casting defects such as shrinkage cavities and gas defects were obtained.

[0031]

[Table 1] Chemical composition (mass%) C Si Mn Cr Mo Mo Fe 0.40 0.70 0.75 1.05 0.20 Balance

[0032]

As described above, according to the vacuum suction pressurizing casting method and apparatus of the present invention, the mold cavity and / or the riser on the mold surface in the vicinity of the final filling portion of the molten metal separated from the runner. Since a suction port is formed, and suction and pressurization are performed through this suction port, molten metal is rapidly filled in the product cavity and the feeder, and gas bubbles in the molten metal are suppressed. The directional solidification is promoted, and the pressurizing effect on the unsolidified portion of the feeder is further increased, and the feeder effect is promoted. According to such a vacuum suction-pressurization casting apparatus and method of the present invention, a thin casting having a complicated shape can be cast with high quality without casting defects such as shrinkage cavities and gas defects.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view showing a vacuum suction pressurizing casting apparatus according to an embodiment of the present invention.

FIG. 2 is a schematic cross-sectional view showing a state in which a vacuum container of the vacuum suction / pressurizing casting apparatus of one embodiment of FIG. 1 is sealed.

FIG. 3 is a conceptual diagram for explaining the effect of pressurization.

FIG. 4 is a schematic sectional view showing a vacuum suction pressurizing casting apparatus according to another embodiment of the present invention.

FIG. 5 is a diagram schematically showing a molten metal replenishment mechanism that largely influences the generation of various defects, a pressure distribution, and a generation mechanism of porosity that is a starting point of defects.

FIG. 6 is a diagram showing casting defects that occur when the pressure during solidification is properly selected according to the nitrogen (N) level in the molten metal.

[Explanation of symbols]

1: vacuum suction pressurizing casting device, 2: vacuum container,
3: opening, 4: mold, 5: molten metal inlet, 6: runner, 7: product cavity 8
a: riser 8b: heat-saturated part 8c: unsolidified part 9, 10: decompression flexible pipe, 11: decompression control means, 12: decompression device,
13: pressurizing control means, 14: pressurizing device,
Reference numeral 15: molten metal, 16: porous member, 17: closed container, 18: suction port, 19: level sensor 24: protective frame, 25: inert gas supply means.

Claims (10)

[Claims] 1. A reduced pressure suction pressure casting method in which molten metal is poured into a mold by vacuum suction and pressure is applied at least while the molten metal is completely solidified, comprising: (a) a runner;
A product cavity that communicates with the runner and a feeder that communicates with the product cavity, and suction to the mold surface in the vicinity of the final filling portion of the molten metal of the product cavity and / or the feeder away from the runner Preparing a mold for forming a mouth, (b) arranging the mold runner to open in an opening of a vacuum vessel having at least one opening at the bottom, (c) After immersing the runner in the molten metal, the depressurizing device attached to the depressurizing container depressurizes the mold through the suction port to rapidly fill the product cavity and the feeder with the molten metal. Step (d) sealing the opening of the decompression container with a sealing member having at least one or more openings, (d) applying a pressure device attached to the decompression container through the suction port, A reduced pressure suction pressure casting method comprising a step of pressurizing a product cavity and a feeder, and a combination of the above steps. 2. The vacuum suction pressurization casting method according to claim 1, wherein the product cavity and / or
Alternatively, a vacuum suction pressurizing casting method, characterized in that a porous member made of a material having better air permeability than other parts of the mold is provided in a portion close to the feeder. 3. The reduced pressure suction pressure casting method according to claim 1 or 2, wherein the mold surface and the feeder are provided near the final filling portion and / or the final solidification portion of the molten metal of the feeder. Is provided with a suction port that makes the distance between the two smaller than other portions. 4. The vacuum suction pressure casting method according to claim 1, wherein the inside of the vacuum vessel is replaced with an inert gas before the pressure is reduced. . 5. The reduced pressure suction pressure casting method according to any one of claims 1 to 4, wherein the pressure inside the reduced pressure container is pressurized with an inert gas. 6. A vacuum suction pressurizing casting apparatus for pouring molten metal into a mold by vacuum suction and pressurizing the molten metal at least until completion of solidification, comprising: (a) at least one opening at the bottom. A) a reduced pressure container having: (a) a runner disposed in the reduced pressure container, having a runner, a product cavity communicating with the runner, and a riser communicating with the product cavity; Or a mold in which a suction port is formed on the surface of the mold near the final filling portion of the molten metal in the feeder, which is remote from the runner, and the runner opens from the opening of the decompression container; A pressure reducing device attached to the pressure reducing container for immersing the molten metal in the molten metal and then rapidly reducing the pressure through the suction port to rapidly fill the product cavity and the feeder with the molten metal; and (d) at least one. The above openings And a sealing member for sealing the opening of the decompression container, and (d) a pressurizing device attached to the decompression container for pressurizing the product cavity and feeder through the suction port. A vacuum suction pressurizing casting device. 7. The reduced pressure suction pressurizing casting apparatus according to claim 6, wherein the mold has a gas permeability in a portion of the suction port that is close to the product cavity and / or the riser, as compared with other portions of the mold. A vacuum suction pressurizing casting apparatus, which has a porous member made of a good material. 8. The vacuum suction pressurizing casting apparatus according to claim 6 or 7, wherein the mold is provided with the mold surface and the mold surface in the vicinity of a final filling portion and / or a final solidification portion of the molten metal of the feeder. A vacuum suction pressurizing casting device, characterized in that a suction port is formed to make the distance to the feeder smaller than other portions. 9. The reduced pressure suction pressure casting apparatus according to claim 6, wherein the reduced pressure apparatus has a means for replacing the inside of the reduced pressure container with an inert gas before depressurization. A vacuum suction pressurizing casting device. 10. The vacuum suction pressurizing casting apparatus according to claim 6, wherein the pressurizing apparatus has a pressurizing means for applying an inert gas in the vacuum container. Vacuum suction press casting equipment.