JP3268987B2 - Casting method and device using vacuum suction force - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a casting method and an apparatus for sucking a metal such as titanium or aluminum into a mold by using a vacuum suction force.

[0002]

2. Description of the Related Art As a casting method in which metal is sucked into a mold using a vacuum suction force, a metal melted in a crucible is sucked into a mold provided below by utilizing a differential pressure due to vacuum,
Casting. However, a metal such as titanium easily flows along the inner wall of the mold and easily adheres instantly when it comes into contact with the inner wall. Therefore, it is difficult to uniformly cast titanium into the mold. In addition, since the gas and the metal are sucked together during the suction, so-called cavities are formed in the formed casting, and the strength and accuracy are often poor.

Accordingly, a method has been developed in which a crucible is provided below, a mold is provided above the crucible, and the metal is sucked up by vacuum suction. As a result, a gas having a specific gravity lower than that of the metal is sucked first, and then the metal is sucked, thereby preventing the gas from being mixed into the cast metal.

[0004]

However, when vacuuming molten metal by vacuum, the vacuum is directly sucked by a vacuum pump, so that the suction force at the start of suction is not stable and the metal and gas may be mixed. Yes, casting cavities may still form in the casting.

The present invention has been made in view of these points. In a casting method or apparatus in which a crucible is provided below, a mold is provided above the crucible, and the metal is sucked by vacuum suction, gas is applied to the metal. An object of the present invention is to provide a casting method or apparatus capable of uniformly pouring a metal into a mold without being mixed and solving the above-mentioned problem.

[0006]

According to the first aspect of the present invention, a mold chamber box is provided at the upper part of a box-shaped main body, which can be moved up and down, and a mold is installed therein. In addition, a melting chamber equipped with a top-opening crucible containing metal and a heating device for the crucible is provided, and an openable door that seals the melting chamber is provided at an upper portion of the melting chamber, and outside the main body. A vacuum tank having a larger volume than the inside of the mold chamber box is provided, and the inside of the body is evacuated by a pipe leading from the inside of the mold chamber box to the vacuum tank. Is filled with an inert gas, the metal is melted by the heating device, the mold chamber box is lowered, and the gate of the mold is projected downward through a through hole provided in the bottom plate of the mold chamber box, so that the gate of the mold is formed. At the same time as inserting it into the crucible, The inert gas in the mold chamber box is sucked into the mold through the pipe, the metal is sucked into the mold, and flows into the mold.After the sucking is completed, the mold chamber box is raised, and the door is opened. A casting method utilizing a vacuum suction force, which was closed to seal the melting chamber, was adopted.

According to a second aspect of the present invention, there is provided a melting furnace provided with a top opening type crucible containing a metal and a heating device for heating the crucible with a high frequency power source to melt the metal in a lower portion of the box-shaped main body. A chamber is provided, an openable / closable door for sealing the melting chamber is provided in the main body, and a hollow mold chamber box movable vertically up and down is provided above the melting chamber, and an arbitrary mold is placed in the mold chamber box. It is installed, and the gate of the mold is projected downward through a through hole provided in the bottom plate of the mold chamber box. The gate can be inserted into the crucible when opening the openable door and lowering the mold chamber box. A length outside the main body, a vacuum tank having a larger capacity than the inside of the mold chamber box is provided, a pipe is provided from the inside of the mold chamber box to the vacuum tank, and an inert gas is injected into the melting chamber. The vacuum suction force provided with a gas inlet It was use the casting apparatus.

According to a third aspect of the present invention, there is provided a melting chamber in which a crucible having an open top and containing metal and arc bars for melting the metal in the crucible are provided on the left and right sides of the crucible in a lower portion of the box-shaped main body. A hollow mold chamber box movable up and down is provided above the melting chamber, an arbitrary mold is installed in the mold chamber box, and a sprue of the mold is provided on the bottom plate of the mold chamber box. When the mold chamber box is lowered, the mold gate can be inserted into the crucible when the mold chamber box is lowered, and the outer peripheral lower edge of the through hole of the mold chamber box is fitted to the outer periphery of the crucible. Outside the main body, a vacuum tank having a larger capacity than the inside of the mold chamber box is provided, a pipe is provided from the inside of the mold chamber box to the vacuum tank, and an inert gas is injected into the main body. A casting device with an inlet and using vacuum suction .

According to a fourth aspect of the present invention, there is provided a mold chamber box which can be moved up and down in an upper part of a box-shaped main body, a mold is placed in the box, and a metal is put in a lower part of the main body. A melting chamber equipped with a top opening type crucible and a heating device for the crucible is provided, a vacuum tank is provided outside the main body, and the inside of the main body is evacuated by a pipe leading from the inside of the mold chamber box to the vacuum tank. An inert gas was injected into the main body to fill the inside of the main body with the inert gas, the metal was melted by the heating device, the mold chamber box was lowered, and a gate of the mold was provided on the bottom plate of the mold chamber box. At the same time as inserting the sprue of the mold into the crucible by projecting downward through the through hole, suction the inert gas in the mold chamber box through the pipe into the vacuum tank, suction the metal into the mold, And at the same time The metal surface was in contact with the said crucible is pressed by an inert gas, and a casting method using a vacuum suction force.

According to a fifth aspect of the present invention, a vertically movable mold chamber is provided in an upper portion of a box-shaped main body, a mold is placed therein, and a metal is placed in a lower portion of the main body. A melting chamber equipped with a top opening type crucible and a heating device for the crucible is provided, a vacuum tank is provided outside the main body, and the inside of the main body is evacuated by a pipe leading from the inside of the mold chamber box to the vacuum tank. An inert gas was injected into the main body to fill the inside of the main body with the inert gas, the metal was melted by the heating device, the mold chamber box was lowered, and a gate of the mold was provided on the bottom plate of the mold chamber box. At the same time, the inert gas in the mold chamber box is sucked through the pipe into the vacuum tank by inserting the sprue of the mold into the crucible by projecting downward through the through hole. Spiral spiral so as to be sucked To suction the metal into the mold, caused to flow, and a casting method using a vacuum suction force.

According to a sixth aspect of the present invention, there is provided a mold chamber box which can be moved up and down in an upper portion of a box-shaped main body, a mold is placed in the box, and a metal is placed in a lower portion of the main body. A melting chamber equipped with a top opening type crucible and a heating device for the crucible is provided, a vacuum tank is provided outside the main body, and the inside of the main body is evacuated by a pipe leading from the inside of the mold chamber box to the vacuum tank. An inert gas was injected into the main body to fill the inside of the main body with the inert gas, the metal was melted by the heating device, the mold chamber box was lowered, and a gate of the mold was provided on the bottom plate of the mold chamber box. At the same time, the mold gate is inserted into the crucible by projecting downward through the through hole, and at the same time, the inert gas in the mold chamber box is sucked through the pipe into the vacuum tank. While rotating with the above metal It sucked into the mold and allowed to flow, and a casting method using a vacuum suction force.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. FIGS. 1 to 3 show an apparatus according to a first embodiment of the present invention. An opening / closing lid 2 is provided on an upper end surface of a box-shaped main body 1, and the opening / closing lid 2 is hinged to one side of the main body 1. It can be opened and closed freely. In the lower part of the main body 1, metal 4
Opening type copper crucible 5 in which crucible 5 is placed and this crucible 5
A melting chamber 7 having a heating device 6 composed of a high-frequency power supply for heating the metal inside is provided, and openable and closable doors 8 for closing the melting chamber 7 in the main body 1 are provided. These doors 8, 8
Are the storage recesses 9, 9 provided in the main body 1 when the melting chamber 7 is opened.
Respectively. Further, an injection path 10 for an inert gas to be injected from outside the main body 1 is provided in the melting chamber 7.

A hollow mold chamber box 11 which is movable up and down is provided in the main body 1 above the melting chamber 7.
A mold 12 having an arbitrary shape is installed in the inside. The mold chamber box 11 has a lid 11a removably fixed to the upper end by screws.
The lid 11a has a column 13 erected from the center of the upper surface, and the column 13 passes through the central hole 2a of the opening / closing lid 2. And a column 1 protruding from the upper surface of the opening / closing lid 2
A flange-shaped handle 14 is fixed to the upper end of the handle 3. A screw 13a is provided in the middle and outer periphery of the column 13, and a screw 2b is provided in the middle of the center hole 2a of the opening / closing lid 2.
Screwed on. The upper portion of the central hole 2a has a large diameter with a step. This large diameter portion and the handle 14
A spring 15 is provided on the outer circumference of the support 13 between the support 13 and the support 13 and constantly urges the support 13 to be lifted upward.

In the center of the bottom of the mold chamber box 11, a through hole 1 is provided.
6, and a substantially annular packing 17 is provided on the inner periphery of the upper surface of the through hole 16. The upper portion of the mold 12 is pressed by a pressing plate 19 supported by a spring 18 provided on the lower surface of the lid 11a, the lower portion of the mold 12 is placed on the packing 17, and the gate 12a is inserted into the through hole 12a. 16 and project downward. The sprue 12a has a length that allows the doors 8 and 8 to be opened and inserted into the crucible 5 when the mold chamber box 11 is lowered. The bottom of the mold chamber box 11 is supported by supports 20, 20 projecting from both sides of the inner circumference of the main body 1. Each of the supports 20 and 20 is provided in a storage chamber 2 provided on both inner peripheral sides of the main body 1.
1 and 21 can be stored freely.

A vacuum tank 22 having a volume at least twice the volume of the main body 1 is provided below the main body 1, and the vacuum tank 22 can be evacuated by a vacuum pump (not shown). One end of the vacuum tank 22 is connected to the mold chamber box 11, and the other end of the vertically lowered pipe 23 is introduced from above. An opening / closing valve 24 is provided at a point where the pipe 23 is introduced into the vacuum tank 22. The lower end of the pipe 23 pushes the opening / closing valve 24 due to the lowering of the pipe 23 accompanying the lowering of the mold chamber box 11, and the opening / closing valve 24 opens. When the pipe 23 rises, the on-off valve 24 closes. Further, the on-off valve 24 can be electrically opened and closed by an appropriate operation. The pipe 23 is slidably supported by a guide 25 provided in the mold chamber box 11. In addition, a window 26 through which the inside and the inside of the melting chamber 7 can be observed when the doors 8
Is provided.

In the case of the first embodiment of the present invention, when the handle 14 is turned in the loosening direction, the column 13 and the lid 11a integral therewith rotate, and the column 13 is screwed to the opening / closing lid 2 and The screws of the lid 11a and the mold chamber box 11 are released. Then, the opening / closing lid 2 is opened, and an arbitrary mold 12 is set in the mold chamber box 11. Thereafter, when the opening / closing lid 2 is closed and the handle 14 is turned in the tightening direction, the column 13 is screwed to the opening / closing lid 2, and at the same time, the lid 11a is screwed to the mold chamber box 11, and the inside of the mold chamber box 11 is sealed. Is done. Then, the vacuum tank 22 is evacuated, the on-off valve 24 is opened, and the air in the main body 1 is evacuated through the mold chamber box 11 to make all the vacuum. After confirming that the inside of the main body 1 has become vacuum, argon gas is injected into the main body 1 from the inert gas injection path 10, and the inside of the main body 1 is filled with argon gas.

After that, the metal 4 in the crucible 5 with the power of the heating device 6 composed of a high-frequency power source turned on is melted, the on-off valve 24 in the vacuum tank 22 is closed, and the vacuum tank 22 is evacuated. Then, the doors 8 at the upper end of the melting chamber 7 are opened,
After confirming the dissolution of the metal 4 from the window 26, the support 20 supporting the mold chamber box 11 is retreated toward the storage chamber 21 and the handle 14 is turned in the tightening direction. When the mold chamber box 11 is melted and pressed downward as it is, the mold chamber box 11 descends, and the gate 12 a of the mold 12 protruding from the through hole 16 on the lower surface of the mold chamber box 11 is embedded in the metal 4 in the crucible 5.
At the same time, the on-off valve 24 opens, and the mold chamber box 1
Argon gas in the vacuum tank 2
2, and the metal 4 is formed by the suction force into the gate 1 of the mold 12.
It is sucked into the mold 12 from the through passage 12b of 2a.
FIG. 3 shows this state.

When the completion of the suction is confirmed by a vacuum gauge (not shown), the handle 14 is pulled up to lift the mold chamber box 11, and the supports 20 and 20 are made to protrude. Put in. Then, without turning off the power of the heating device 6, the doors 8 and 8 of the melting chamber 7 are closed, and the handle 14 is further turned in the same direction as described above,
The lid 11a of the mold chamber box 11 is opened, and the open / close lid 2 is opened, and the mold 12 in the mold chamber box 11 is taken out. Then, only the metal 4 consumed by the through holes 16 at the bottom of the mold chamber box 11 is placed in the central recesses of the doors 8 and 8 by means of a ceramic sandwich. Then, the main body 1 is evacuated again, and thereafter the main body 1 is filled with argon gas, the doors 8 and 8 are opened, and the metal 4 is dropped into the crucible 5. And when casting again, the above-mentioned process is repeated. When the casting is completed, the doors 8 and 8 are closed while the main body 1 is filled with the argon gas, and the power supply of the heating device 6 is turned off.

Next, a second embodiment of the present invention will be described with reference to FIGS. The second embodiment differs from the first embodiment in the melting chamber and the heating device, and the other configurations are the same. Therefore, only different points will be described. In this apparatus, the melting chamber is not a closed type, and a crucible base 27 is provided at the lower part of the main body, and extendable sliding insulating columns 28 are provided on both sides of the crucible base 27. The upper end is fixed to the bottom of the mold chamber box 11. Each of these sliding insulating columns 28 is always urged to extend upward. Also, each of these sliding insulating columns 28
An arc bar 29 is directed horizontally to a metal 31 placed on a copper crucible 30 provided at the center of the crucible base 27. An inert gas injection passage 32 is provided on the inner periphery of the main body 1 beside the crucible base 27. Further, a lower edge 16a is provided which hangs down along the inner periphery of the through hole 16 at the center of the bottom surface of the mold chamber box 11.
When 1 is lowered, the lower edge 16 a is fitted to the outer periphery of the crucible 30. On both sides of the crucible 30, glass wool packings 33 for receiving the respective arc rods 29 are provided.

In the case of the second embodiment, when the handle 14 is turned in the loosening direction, the column 13 and the lid 11a integral therewith are rotated, and the column 13 is screwed to the opening / closing lid 2 and the lid 11a. Are screwed off with the mold chamber box 11, respectively. Then, the opening / closing lid 2 is opened, and an arbitrary mold 12 is set in the mold chamber box 11. Thereafter, when the opening / closing lid 2 is closed and the handle 14 is turned in the tightening direction, the column 13 is screwed to the opening / closing lid 2, and at the same time, the lid 11a is screwed to the mold chamber box 11, and the inside of the mold chamber box 11 is sealed. Is done. Then, the vacuum tank 22 is evacuated, the on-off valve 24 is opened, and the air in the main body 1 is evacuated through the mold chamber box 11 to make all the vacuum. After confirming that the inside of the main body 1 has become vacuum, an argon gas is injected into the main body 1 from the inert gas injection path 32, and the inside of the main body 1 is filled with argon gas.

Thereafter, the power is supplied to the arc rods 29, 29, and the metal 31 in the crucible 30 is melted.
The on-off valve 24 is closed, and the inside of the vacuum tank 22 is evacuated. When the dissolution of the metal 31 is confirmed from the window 26, the support body 20 supporting the mold chamber box 11 is retreated to the storage chamber 21 and the handle 14 is turned in the tightening direction. When the mold chamber box 11 is pressed downward as it is, the mold chamber box 11 is lowered, and the lower edge 16a protruding from the through hole 16 on the lower surface of the mold chamber box 11 is fitted on the outer periphery of the crucible 30, and the crucible 30 is sealed. At the same time the gate 12 of the mold 12
a is embedded in the metal 31. At the same time, the on-off valve 24 is opened, and the argon gas in the mold chamber box 11 instantaneously enters the vacuum tank 22 through the pipe 23, and the suction force causes the metal 31 to pass through the through hole 12 a of the gate 12 a of the mold 12.
b is sucked into the mold 12. FIG. 6 shows this state.

When the suction completion is confirmed by a vacuum gauge (not shown), the handle 14 is pulled up to lift the mold chamber box 11, and the supports 20, 20 are protruded. Put in. Then, turn off the power of the arc rods 29, 29 and handle 1 as described above.
4 in the direction to further loosen the cover 11 of the mold chamber box 11.
is opened, and the opening / closing lid 2 is opened, and the mold 12 in the mold chamber box 11 is taken out. Then, only the metal 31 consumed in the crucible 30 from the through hole 16 at the bottom of the mold chamber box 11
With a ceramic clip. And when casting again, the above-mentioned process is repeated.

Next, a third embodiment of the present invention will be described with reference to FIGS. The third embodiment differs from the second embodiment only in the configuration in which the main body 1 is inverted and the configuration in which the metal is pressed from the back surface of the metal with an inert gas such as an arc gas, and the other configurations are the same. It is. Therefore, only different points will be described. That is, the vacuum tank 22 and the main body 1 are separated, and the support column 3 is
4 and a rotary jig 3 provided on one side of the support column 34.
5, a shaft 1a protruding from one side of the main body 1 is rotatably supported. In addition, an inert gas injection path 36 is provided through the crucible base 27 to the upper surface of the crucible 30 in contact with the lower surface of the metal 31. In the state shown in FIG. 7, the inert gas passing through the injection path 36 is injected into the main body 1 through a groove (not shown) provided on the upper surface of the crucible 30 in contact with the metal 31. Further, the pipe 2 in the above-described embodiment example
Instead of 3, a passage 37 is provided from the tank 22 to the inside of the mold chamber box 11 or the main body 1 through the support column 34, the rotary jig 35, the shaft 1 a, the main body 1, the opening / closing lid 2, and the column 13.

In the case of the third embodiment, the second embodiment
Similarly to the embodiment, the main body 1 is filled with argon gas, the vacuum tank 22 is evacuated, the mold chamber box 11 is lowered, and the lower edge 16a protruding from the through hole 16 on the lower surface of the mold chamber box 11 is formed. The crucible 30 is fitted around the outer periphery of the crucible 30, and the crucible 30 is sealed.
Embedded in At the same time, the on-off valve 24 is opened, and the argon gas in the mold chamber box 11 instantaneously enters the vacuum tank 22 through the passage 37, and the metal 31 is drawn from the through-hole 12 b of the gate 12 a of the mold 12 by this suction force. It is sucked into 12. At the same time, the main body 1 is rotated 180 degrees by the rotating jig 35, as shown in FIG. Then, an argon gas is injected from the injection path 36 for the inert gas, and the pressure of the argon gas is applied to the soft metal 31 which is in contact with the upper surface of the crucible 30 and has not yet been melted. As a result, the metal 31 comes into close contact with the gate 12a, and the density of the sucked metal 31 can be increased.

FIGS. 9 and 10 show a fourth embodiment of the present invention. In the fourth embodiment, the second
This embodiment is substantially the same as the embodiment described above, except that a spiral blade 38 having the central axis of the mold chamber box 11 as an axis is provided between the inner periphery of the mold chamber box 11 and the outer periphery of the mold 12. In this embodiment, the main body 1 is similar to the second embodiment.
Is filled with argon gas, the vacuum tank 22 is evacuated, the mold chamber box 11 is lowered, and the lower edge 16a protruding from the through hole 16 on the lower surface of the mold chamber box 11 is fitted to the outer periphery of the crucible 30 to form a crucible. 30 is sealed and at the same time mold 12
Gate 12a is embedded in metal 31. At the same time, the opening / closing valve 24 is opened, and the argon gas in the mold chamber box 11 instantaneously enters the vacuum tank 22 through the pipe 23, and the metal 31 melted by the suction force turns the gate 12 a of the mold 12.
Is sucked into the mold 12 from the through passage 12b.

When the argon gas in the mold chamber box 11 is sucked, it is guided by the spiral blades 38 and spirally sucked upward, so that the molten metal 31 sucked into the mold 12 is sucked up. Also spirally enters the mold 12. Therefore, the metal 31 reaches every corner in the mold 12 due to the centrifugal force, so that the metal can be evenly distributed along the shape of the mold 12 and uniform casting can be performed.

In the case of the fourth embodiment, the spiral blades 38 are provided in the mold chamber box 11. However, the present invention is not limited to this, and an inert gas sucked by an appropriate method may be spirally swirled in the mold. Any material can be used as long as it can be wound around. Therefore, for example, a helical rotary blade that is rotated by an appropriate driving source is provided between the inner circumference of the mold chamber box 11 and the outer circumference of the mold 12, and the inert gas is spirally swirled and sucked by turning the rotary blade. can do. Also, as shown in FIG.
The mold 12 is placed on a turntable 39, and the turntable 39 is rotated by a motor 40. When the inert gas is sucked, convection spirally spiraling in the hollow portion of the mold 12 is generated, or The suction can be performed while generating a convection rotating around the inner periphery of the hollow portion of the mold 12 by the centrifugal force.

As shown in FIG. 12, three spiral holes 41 communicating from the top of the hollow portion of the mold 12 to the upper surface of the mold 12 are provided.
By closing the openings of the spiral holes 41 on the upper surface with a filter 42 made of air-permeable glass wool or the like, when the inert gas is sucked from the upper part of the mold chamber box 11, the upper part of the mold 12 is closed. A spiral convection occurs in the hollow portion of the mold 12 by the spiral hole 41. As shown in FIG. 13, a spiral blade 44 is provided on the turntable 43 on which the mold 12 is placed, between the inner periphery of the mold chamber box 11 and the outer periphery of the mold 12. The mold 12 is rotatably supported by a pairing 45 provided on the lower surface, while the mold 12 is the mold 12 shown in FIG.
When the inert gas is sucked from the upper portion of the mold chamber box 11, the gas hits these blades 44 and the turntable 43 rotates, and the inert gas is sucked by spirally swirling the inside and outside of the mold 12, and Spiral convection also occurs in the hollow portion of the mold 12 due to the spiral hole 41 on the upper part of the mold 12.

The present invention is not limited to the above embodiment. A mold chamber box is provided at the upper part of the box-shaped main body, which can be moved up and down, and a mold is installed therein. A melting chamber equipped with a top-opening type crucible and a heating device for the crucible is provided, a vacuum tank is provided outside the main body, and the inside of the main body is evacuated by a pipe leading from the inside of the mold chamber box to the vacuum tank. An inert gas was injected into the main body to fill the inside of the main body with the inert gas, the metal was melted by the heating device, the mold chamber box was lowered, and a gate of the mold was provided on the bottom plate of the mold chamber box. At the same time as inserting the sprue of the mold into the crucible by projecting downward through the through-hole, the inert gas in the mold chamber box is sucked through the pipe into the vacuum tank, and the metal is sucked into the mold. Inflow casting method If even there.

In each of the above embodiments, the support 1
A packing material is provided at the upper and lower ends of the hole 2a of the opening / closing lid 2 through which the support 3 extends, so that the airtightness in the main body 1 is not leaked to the outside even if the support 13 moves as the handle 14 moves up and down. ing.

[0031]

According to the first and second aspects of the present invention, the interior of the mold chamber is filled with an inert gas, the vacuum tank is evacuated, and then the mold gate is buried in the molten metal. At the same time, by opening the on-off valve of the vacuum tank, the inert gas in the mold chamber box is sucked into the vacuum tank, and the molten metal is sucked into the mold by this suction force. Since the specific gravity of the inert gas is lighter than that of the metal, the gas is first sucked up, and then the metal is sucked up.
At this time, since the suction is performed using a vacuum tank having a larger volume than the inside of the mold chamber box, the suction can be stably performed instantaneously from the start of the suction. Therefore, in the metal cast by this method, no casting cavity is formed, and a casting having a uniform density can be obtained.

In addition, since a door that can be opened and closed to seal the melting chamber is provided in the main body, when one casting operation is completed,
Close this door to seal the melting chamber with the molten metal,
The melting chamber can be filled with an inert gas and the mold can be removed from the mold chamber box. Therefore, subsequently, another mold is set in the mold chamber box, and the metal in the molten state can be used as it is. If the power of the heating device is turned off in a state where the melting chamber is sealed with the door and filled with the inert gas, the metal can be used again at a later date. Therefore, the metal which remains conventionally oxidizes if left as it is,
Since it cannot be used later, it was discarded each time. However, in the present invention, since oxidation of metal can be prevented, it can be used later and is economical.

[0033] The invention of claim 3 provides, in addition to the effect of the invention of claim 1, the fact that when the gate of the mold protruding from the bottom plate of the mold chamber box comes into contact with the metal in the crucible, the mold chamber box is transparent. Since the outer peripheral lower edge of the hole is configured to fit on the outer periphery of the crucible, the portion is sealed, the metal is reliably sucked, and the metal does not spill from the crucible. In addition, since the metal in the crucible is melted by the arc bars on both the left and right sides, the metal is uniformly melted, and the casting does not become uneven due to the difference in melting temperature. In this respect, conventionally, since the metal is melted from one place, even if the same metal is used, there is a possibility that a temperature difference may occur depending on the place, and the casting may become non-uniform.

According to a fourth aspect of the present invention, in addition to the effects of the first aspect of the present invention, the inert gas in the mold chamber box is instantaneously sucked by the vacuum tank, and the metal is applied to the mold by the suction force. It is sucked into the mold from the gate of the gate,
Since the main body is rotated 180 degrees at the same time as the metal is sucked up, the mold is lowered, and the metal is dropped by gravity at the same time as the vacuum suction, and is more easily entered into the mold. And the soft metal 31 which has not melted yet is in contact with the upper surface of the crucible.
As a result, the pressure of the inert gas is applied to the metal, whereby the metal comes into close contact with the gate and the density of the sucked metal can be further increased.

According to a fifth aspect of the present invention, in addition to the effect of the first aspect of the present invention, when the inert gas in the mold chamber box is sucked, it is spirally sucked upward in a spiral. Therefore, the molten metal sucked into the mold also spirals into the mold and enters the mold. Therefore, the metal reaches every corner in the mold due to the centrifugal force, so that the metal can be evenly distributed along the shape of the mold and uniform casting can be performed.

The invention of claim 6 provides the effect of the invention of claim 1 in addition to the effect of the invention of claim 1 described above. When the inert gas in the mold chamber box is sucked, the mold is rotated by centrifugal force to rotate the mold. In order to suck while generating convection that rotates, the molten metal sucked into the mold also rotates in the mold,
The metal reaches every corner in the mold due to the centrifugal force, so that the metal can be evenly distributed along the shape of the mold and uniform casting is possible.

[Brief description of the drawings]

FIG. 1 is a sectional front view of a first embodiment of the present invention.

FIG. 2 is a sectional front view of the first embodiment of the present invention.

FIG. 3 is a sectional front view in a state where the mold chamber box according to the first embodiment of the present invention is lowered and a gate of the mold is embedded in metal.

FIG. 4 is a sectional front view of a second embodiment of the present invention.

FIG. 5 is a sectional side view of a second embodiment of the present invention.

FIG. 6 is a sectional front view in a state where a mold chamber box according to a second embodiment of the present invention is lowered and a gate of the mold is embedded in metal.

FIG. 7 is a sectional front view of a third embodiment of the present invention.

FIG. 8 is a sectional front view in a state where a mold chamber box according to a third embodiment of the present invention is lowered and a gate of the mold is embedded in metal.

FIG. 9 is a sectional front view of a fourth embodiment of the present invention.

FIG. 10 is a perspective view showing the inside of a mold chamber box according to a fourth embodiment of the present invention with the lid thereof opened.

FIG. 11 is a cross-sectional view of another specific example of the fourth embodiment of the present invention.

FIG. 12 is a cross-sectional view of another specific example of the fourth embodiment of the present invention.

FIG. 13 is a cross-sectional view of another specific example in the fourth embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Main body 2 Opening / closing lid 4 Metal 5 Crucible 6 Heating apparatus by high frequency 7 Melting chamber 8 Door 10 Injection path of inert gas 11 Mold chamber box 12 Mold 12a Gate 13 Post 14 Handle 15 Spring 16 Through hole 19 Press plate 20 Supporting body 22 Vacuum tank 23 Pipe 24 On-off valve 27 Crucible base 28 Sliding insulating column 29 Arc rod 30 Crucible 31 Metal 32 Inert gas injection path 34 Supporting column 35 Rotating jig 36 Inert gas injection path 37 Spiral blade

Claims (6)

(57) [Claims] 1. A crucible having an upper surface opening type in which a metal is placed in a lower part of the main body, wherein a mold chamber box which can be moved up and down is provided in an upper part of a box-shaped main body. A melting chamber equipped with a heating device for the crucible is provided, and an openable and closable door for sealing the melting chamber is provided at an upper portion of the melting chamber. A vacuum tank is provided, the inside of the main body is evacuated by a pipe leading from the inside of the mold chamber box to the vacuum tank, an inert gas is subsequently injected into the main body, the inside of the main body is filled with the inert gas, and the metal is heated by the heating device. Is melted, the mold chamber box is lowered, the mold gate is projected downward through a through hole provided in the bottom plate of the mold chamber box, and the mold gate is inserted into the crucible and simultaneously in the vacuum tank. The pipe inside the mold chamber Activating gas is sucked, the metal is sucked up into the mold, and is allowed to flow into the mold.After the sucking is completed, the mold chamber box is raised, the door is closed and the melting chamber is sealed, and a vacuum is provided. Casting method using suction force. 2. A melting chamber having a top-opening type crucible containing a metal and a heating device for heating the crucible with a high-frequency power source to melt the metal is provided at a lower portion in the box-shaped main body. An openable door for closing the melting chamber is provided, and a hollow mold chamber box movable up and down is provided above the melting chamber, and an arbitrary mold is installed in the mold chamber box. Is projected downward through a through hole provided in the bottom plate of the mold chamber box, and the spout is opened to open and close the door so that the mold chamber box can be inserted into the crucible when the mold chamber box is lowered. In addition, a vacuum tank having a larger volume than the inside of the mold chamber box was provided, a pipe leading from the inside of the mold chamber box to the vacuum tank was provided, and a gas inlet for injecting an inert gas into the melting chamber was provided. Using vacuum suction force Casting equipment. 3. A melting chamber having a top-opening crucible containing a metal and arc rods for melting the metal in the crucible provided on the left and right sides of the crucible are provided in a lower portion of the box-shaped main body. A hollow mold chamber box that can move up and down is provided at the top,
An arbitrary mold is placed in the mold chamber box, and the gate of the mold is projected downward through a through hole provided in the bottom plate of the mold chamber box.When the mold chamber box is lowered, the mold is placed in the crucible. A gate can be inserted, and the lower peripheral edge of the through hole of the mold chamber box is fitted to the outer periphery of the crucible. A vacuum tank having a larger capacity than the inside of the mold chamber box is provided outside the main body. A casting apparatus utilizing vacuum suction, wherein a pipe is provided from the inside of the mold chamber box to the vacuum tank, and an inlet for injecting an inert gas is provided in the main body. 4. A top-opening crucible containing a metal, wherein a mold chamber is provided in an upper part of a box-shaped main body, which can be moved up and down, and a mold is placed therein. A melting chamber equipped with a heating device for the crucible is provided, a vacuum tank is provided outside the main body, and the inside of the main body is evacuated by a pipe leading from the inside of the mold chamber box to the vacuum tank. To fill the inside of the main body with an inert gas, melt the metal by the heating device, lower the mold chamber box, and project the gate of the mold downward through a through hole provided in the bottom plate of the mold chamber box. At the same time, the gate of the mold is inserted into the crucible, and at the same time, the inert gas in the mold chamber box is sucked through the pipe into the vacuum tank, and the metal is sucked and flowed into the mold. And touch the crucible above A casting method using vacuum suction, characterized in that a metal surface is pressed with an inert gas. 5. A top-opening crucible containing a metal, wherein a mold chamber is provided in the upper part of the box-shaped main body, the mold chamber box being movable up and down. A melting chamber equipped with a heating device for the crucible is provided, a vacuum tank is provided outside the main body, and the inside of the main body is evacuated by a pipe leading from the inside of the mold chamber box to the vacuum tank. To fill the inside of the main body with an inert gas, melt the metal by the heating device, lower the mold chamber box, and project the gate of the mold downward through a through hole provided in the bottom plate of the mold chamber box. At the same time, the gate of the mold is inserted into the crucible, and at the same time, the inert gas in the mold chamber box is sucked through the pipe into the vacuum tank, and the inert gas is spirally swirled and sucked. The above metal into the mold Characterized by pulling and inflow,
Casting method using vacuum suction. 6. A crucible having a top-opening type in which a metal is placed in a lower portion of the main body, wherein a mold chamber box which can move up and down is provided in an upper portion of the box-shaped main body. A melting chamber equipped with a heating device for the crucible is provided, a vacuum tank is provided outside the main body, and the inside of the main body is evacuated by a pipe leading from the inside of the mold chamber box to the vacuum tank. To fill the inside of the main body with an inert gas, melt the metal by the heating device, lower the mold chamber box, and project the gate of the mold downward through a through hole provided in the bottom plate of the mold chamber box. At the same time, the gate of the mold is inserted into the crucible and at the same time the inert gas in the mold chamber box is sucked through the pipe into the vacuum tank, and the metal is placed in the mold while rotating the mold. It is characterized by suction and inflow Casting method using vacuum suction force.