JP3576490B2 - Metal gas generator - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a metal gas generator used in a reduction casting apparatus for casting by reducing an oxide film on the surface of a molten metal.
[0002]
[Prior art]
There are various casting methods such as gravity casting (GDC), low pressure casting (LPDC), die casting (DC), squeeze (SC), and thixomold. In each of these methods, a molten metal is injected into a cavity of a molding die and molded into a predetermined shape. Among these casting methods, those in which an oxide film is easily formed on the surface of the molten metal, for example, in aluminum casting, the surface tension is increased due to the oxide film formed on the surface of the molten metal, and the fluidity of the molten metal, the flowability of the molten metal, There is a problem that the weldability is reduced and casting defects such as unfilled molten metal and hot lines are generated.
[0003]
As a method of solving these problems, the present applicant has developed a method of casting by reducing an oxide film formed on the surface of a molten aluminum by a reduction casting method. In this reduction casting method, a magnesium nitrogen compound (Mg) having a strong reducing property using nitrogen gas and magnesium gas is used. ₃ N ₂ ), And the magnesium nitrogen compound acts on the molten aluminum to reduce and cast an oxide film formed on the surface of the molten metal. By injecting the molten metal with the magnesium nitrogen compound precipitated on the surface of the cavity of the mold, the oxide film on the surface of the molten metal is reduced when the molten metal comes into contact with the surface of the cavity to reduce the surface tension of the molten metal. As a result, the fluidity and wettability of the molten metal can be improved, which makes it possible to easily produce a cast product having no casting defects and excellent appearance with no hot water wrinkles or the like.
[0004]
[Problems to be solved by the invention]
The above reduction casting method is characterized in that an oxide film formed on the surface of the molten metal is reduced by causing a reducing compound such as a magnesium nitrogen compound to act on the molten metal. Since this reducing compound has a strong reducing property, it is necessary to generate it in a non-oxygen atmosphere, but at the same time, with respect to a metal gas such as a magnesium gas for generating the reducing compound, it is easy for these to react with oxygen. Must be handled in a non-oxygen atmosphere.
In the case where a magnesium nitrogen compound as a reducing compound is produced, it is produced by reacting a metal gas such as magnesium gas with a reactive gas such as nitrogen gas. Since a metal gas such as a magnesium gas is extremely liable to react with oxygen, a metal gas is generated in a non-oxygen atmosphere to allow a reduction compound to act on a molten metal and to perform an effective reduction casting. It is necessary to be able to introduce metal gas into the cavity.
[0005]
In the reduction casting method, it is possible to perform reduction casting using not only the magnesium nitrogen compound but also various reducing compounds. If the material has a higher oxidizing property than the molten metal material, it can be reacted with the reactive gas as a metal gas to generate a reducing compound.
The present invention can be suitably used for such reduction casting, and easily and efficiently manufactures a high-quality cast product by reducing and casting an oxide film formed on the surface of a molten metal. It is an object of the present invention to provide a metal gas generator that can be used in a reduction casting apparatus capable of reducing the temperature.
[0006]
[Means for Solving the Problems]
The present invention has the following configuration to achieve the above object.
That is, a metal gas generator used in a reduction casting apparatus for casting by reducing an oxide film on the surface of a molten metal with a reducing compound generated by reacting a metal gas and a reactive gas, wherein the metal serving as the metal gas is used. A first tank for storing, a vaporizer for vaporizing the metal, and a second tank for storing an inert gas for introducing the metal into the vaporizer, wherein the second tank, the vaporizer, And the first tank is connected so that the metal can flow into the pipeline from the first tank.
Further, the first tank and the second tank are connected so that the metal can flow into the pipe by pressurizing the first tank with an inert gas stored in the second tank. It is characterized by having done.
[0007]
A metal gas generator used in a reduction casting apparatus for reducing and casting an oxide film on the surface of a molten metal by a reducing compound generated by reacting a metal gas and a reactive gas, wherein the metal gas generating the metal gas is used. A vaporizer that melts and vaporizes, a gas lock chamber that is installed above the vaporizer in communication with the vaporizer, shuts off outside air, is kept airtight, and stores a metal piece of the metal; A partition plate is provided for controlling the supply of the metal pieces from the gas lock chamber to the vaporizer by blocking communication between the vaporizer and the gas lock chamber.
Further, since the inert gas is introduced as a carrier into the vaporizer and the metal gas vaporized in the vaporizer is provided so as to be introduced into the cavity of the molding die, the metal can be easily introduced from the vaporizer into the cavity. Gas can be transported.
Further, by providing a flow control means for controlling the flow rate of the inert gas introduced into the vaporizer, supply of metal to the vaporizer, transport of metal gas from the vaporizer to the cavity of the molding die are provided. Is done precisely.
The use of magnesium as the metal is effective in that magnesium has an effective reducing action, is easily vaporized, and is stable from a high temperature during casting to a normal temperature.
[0008]
Summary of the Invention
The metal gas generator according to the present invention vaporizes a metal for generating a reducing compound that reduces an oxide film formed on the surface of a molten metal in a state in which outside air is shut off, and transfers the metal gas to a cavity of a molding die or the like. It is intended to be transportable.
FIG. 1 is a diagram showing a main structure of a reduction casting apparatus according to the present invention, in which a first tank 60, a vaporizer 70, and a second tank 65 are connected by pipes so as to vaporize metal in a state in which outside air is shut off. It is. The term “metal gas” as used in the present invention means a substance that generates a reducing compound having a strong reducing action by reacting with a reactive gas such as nitrogen gas, and the term “metal” means a metal that generates this metal gas. I do.
[0009]
The first tank 60 is a device for storing a metal such as magnesium, for example, the vaporizer 70 is a device for vaporizing the metal introduced from the first tank 60, and the second tank 65 is a device for storing a non-metal such as argon gas. It is a device that stores active gas. The inert gas stored in the second tank 65 transports the metal from the first tank 60 to the vaporizer 70 or transports the metal gas vaporized in the vaporizer 70 to the cavity of the mold 90 or the like. It works.
[0010]
The second tank 65 and the vaporizer 70 are connected via a pipe 71 and a pipe 72 with a flow control device 80 interposed therebetween. The flow control device 80 includes a valve mechanism for controlling the flow rate and pressure of the inert gas stored in the second tank 65, a flow meter, and the like. Note that the flow control device 80 does not necessarily have to be arranged between the pipes 71 and 72. Reference numerals 82 and 84 denote valves interposed in the pipes 71 and 72, respectively.
The first tank 60 and the vaporizer 70 are connected via a pipe 74 branched from the flow controller 80. 86 is a valve interposed in the pipe 74.
The second tank 65 and the first tank 60 are also connected via a pipe 78 branched from the pipe 71 on the upstream side of the valve 82. The pipe 74 is connected to the side of the first tank 60 facing the flow control device 80, while the pipe 78 is connected to the other end of the first tank 60. Reference numeral 88 denotes a valve interposed in the pipe 78.
[0011]
The metal can be introduced from the first tank 60 into the vaporizer 70 by opening and closing the valves 86 and 84. Alternatively, metal (powder) can be introduced from the first tank 60 to the vaporizer 70 by the gas pressure of the inert gas stored in the second tank 65 with the valve 88 opened and the valve 82 closed. . The amount of metal (powder) introduced into the vaporizer 70 can be controlled by opening and closing the valves 86 and 84 and using the flow controller 80.
[0012]
In the vaporizer 70, the metal introduced into the vaporizer 70 is heated and vaporized. When the metal is magnesium, the magnesium sublimates at about 700 ° C. to 850 ° C. to become a magnesium gas, and the temperature of the vaporizer 70 may be raised to this level. The vaporizer 70 includes heating means such as a heater for heating to a predetermined temperature in order to generate a metal gas. Further, the vaporizer 70 is formed in a closed space so that outside air does not enter, and has a non-oxygen atmosphere so that the metal gas does not react with oxygen. In order to make the vaporizer 70 a non-oxygen atmosphere, the valves 82, 84 and 87 are opened to allow the inert gas to flow into the vaporizer 70 from the second tank 65, and the air in the vaporizer 70 is discharged from the vaporizer 70. What should I do? Note that the pressure in the vaporizer 70 can be reduced to a non-oxygen atmosphere.
The valve 87 is closed with the inside of the vaporizer 70 in a non-oxygen atmosphere, and metal (powder) is introduced into the vaporizer 70 from the first tank 60, and then the valve 84 is closed to vaporize the metal in the vaporizer 70. Let it.
[0013]
In the vaporizer 70, the metal powder introduced from the first tank 60 can be sublimated as it is, and the metal gas can be sent out toward the molding die 90. However, the metal gas is supplied from the first tank 60. It is also possible to melt the metal (powder) once in the vaporizer 70 and to send the vaporized metal gas to the mold 90 as an inert gas carrier. When the metal is melted in the vaporizer 70 and the metal gas is sent to the mold 90, the metal is supplied so that a fixed amount of the metal melted in the vaporizer 70 is stored. As a method of replenishing the metal, a method of transporting the metal powder together with the inert gas is also possible. For example, a metal piece such as a magnesium piece may be supplied to the vaporizer 70 to be replenished. The method of replenishing metal pieces has an advantage that unlike the case of using metal powder, the metal powder is not mixed when the metal gas is sent from the vaporizer 70 to the molding die 90.
[0014]
In order to introduce the metal gas vaporized in the vaporizer 70 into the mold 90, the valves 82, 84, 87 are opened, the valve 86 is closed, and the inert gas stored in the second tank 65 is vaporized. 70, and may be fed into the cavity of the mold 90 together with the inert gas via the pipe 76. The metal gas is introduced into the mold 90 by controlling the flow rate and pressure of the inert gas flowing into the vaporizer 70 from the second tank 65 using the opening / closing of the valves 82, 84 and 87 and the flow rate control device 80. be able to.
[0015]
When the metal gas is introduced into the cavity of the molding die 90, the interior of the cavity needs to be in a non-oxygen atmosphere so that the metal gas and oxygen do not react in the cavity. For this purpose, a method of reducing the pressure in the cavity, a method of flowing an inert gas or the like into the cavity and discharging the air in the cavity, and the like can be used.
[0016]
As the inert gas stored in the second tank 65, an inert gas such as an argon gas can be effectively used. If an inert gas such as an argon gas is used, an operation of introducing the metal (powder) into the vaporizer 70 can be performed without reacting with a metal (powder) such as magnesium.
[0017]
In the reduction casting method, a magnesium nitrogen compound (Mg) is reacted by reacting a magnesium gas and a nitrogen gas. ₃ N ₂ ) Is generated, and a reducing compound having a strong reducing action is generated, and the reducing compound is caused to act on the molten metal to perform casting. Therefore, in the reduction casting method, an operation for vaporizing a metal such as magnesium is essential. If a metal gas such as a magnesium gas can be generated, it is possible to generate a reducing compound by reacting with a reactive gas such as a nitrogen gas. An operation of introducing a metal gas and generating a reducing compound in the cavity becomes possible.
[0018]
As described above, the metal gas generator according to the present invention realizes a reduction casting method by allowing a metal such as magnesium to be vaporized by shutting off the outside air and being transported by an inert gas such as an argon gas. It is. The metal gas obtained by vaporizing a metal such as magnesium is used by being introduced into a molding die and used in the case where a reducing compound is allowed to act on the molten metal stored in the storage section or the like. It is also possible to send a metal gas to a bubbling device and use it.
[0019]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment in which the metal gas generator according to the present invention is applied to aluminum casting using a reduction casting method will be described.
FIG. 2 shows a casting apparatus 10 for applying a method of separately introducing a magnesium gas and a nitrogen gas into a cavity of a mold to generate a reducing compound in the cavity, and then injecting a molten aluminum into the cavity to perform casting. Show.
Numeral 12 denotes a molding die, which is connected to a pouring tank 14 and a required amount of molten aluminum 18 is poured from the pouring tank 14 by pulling up a tenon 16. The mold 12 is formed by exposing the inner surface of the cavity to the metal surface.
[0020]
Reference numeral 20 denotes a nitrogen gas cylinder which is connected to the mold 12 via a pipe 22 and opens a valve 24 to introduce nitrogen gas into the mold 12 and discharge air from the mold 12. ing.
Reference numeral 25 denotes an argon gas cylinder serving as a second tank 65, which is connected to a heating furnace 28 through a pipe 26, and by opening a valve 30, argon gas can be introduced into the heating furnace 28. A flow control means 80 is interposed between the argon gas cylinder 25 and the heating furnace 28 to control the flow rate and pressure of the argon gas. Numeral 32 denotes a heater for heating the inside of the heating furnace 28, and the temperature in the furnace is set to 800 ° C. or higher at which magnesium powder described later sublimates.
[0021]
The argon gas cylinder 25 is also connected to a tank 36 as a first tank 60 containing magnesium powder by a pipe 34 in which a valve 33 is interposed, and the tank 36 is connected by a pipe 38 to a pipe downstream of the valve 30. 26. A valve 40 is interposed in the pipe 38. The heating furnace 28 is connected to the mold 12 via a pipe 42 and a pipe 44 that penetrates the tenon 16 and communicates with the mold 12. The pipe 42 is provided with a valve 45.
[0022]
FIGS. 3A and 3B show the structure of the connection port 13 between the pipe 22 and the mold 12. As shown in FIG. 3A, the connection port 13 is formed in a tapered hole extending outward on the outer wall of the molding die 12, and a connection plug (not shown) attached to the tip of the pipe 22 is formed in the tapered hole. It is detachably attached.
Further, the connection port 13 communicates with the inside of the molding die 12 through the air vent hole 15 of the ordinary molding die 12.
[0023]
A casting method using the casting apparatus 10 will be described below.
First, the valve 24 is opened, nitrogen gas is introduced into the mold 12 from the nitrogen gas cylinder 20 via the pipe 22, and the air in the mold 12 is exhausted by the nitrogen gas. The air in the molding die 12 is discharged from an air vent hole (not shown) in the upper part of the molding die, and the inside of the molding die 12 becomes a non-oxygen atmosphere. After exhausting the inside of the mold 12, the valve 24 is closed once.
[0024]
While the air in the mold 12 is being exhausted, the valve 30 is opened and argon gas is introduced into the heating furnace 28 to keep the heating furnace 28 in a non-oxygen atmosphere.
Next, the valve 30 is closed, the valve 40 is opened, and the magnesium powder in the tank 36 is fed into the heating furnace 28 together with the argon gas by the argon gas pressure. Since the heating furnace 28 is heated by the heater 32 to a furnace temperature of 800 ° C. or higher at which the magnesium powder sublimes, the magnesium powder sent into the heating furnace 28 is sublimated into magnesium gas.
[0025]
Next, the valve 40 is closed, the valve 30 and the valve 45 are opened, and the argon gas pressure and the flow rate are adjusted to introduce the magnesium gas into the mold 12 through the pipes 42 and 44.
After the magnesium gas is introduced into the mold 12, the valve 45 is closed and the valve 24 is opened to introduce the nitrogen gas into the mold. By introducing nitrogen gas into the mold 12, the magnesium gas and the nitrogen gas react in the cavity of the mold 12 and react with the magnesium nitrogen compound (Mg). ₃ N ₂ ) Is generated. This magnesium nitrogen compound precipitates as powder on the surface of the cavity.
[0026]
In this state, next, the tenon 16 is pulled up, and the molten aluminum in the pouring tank 14 is supplied into the mold 12.
The molten aluminum poured into the mold 12 reacts on the surface of the cavity with the magnesium nitrogen compound precipitated on the surface of the cavity, and the magnesium nitrogen compound is oxidized on the surface of the molten aluminum. By depriving the coating of oxygen, the surface of the molten aluminum is reduced to pure aluminum. Oxygen remaining in the mold 12 or oxygen mixed in the aluminum melt becomes magnesium oxide or magnesium hydroxide and is taken into the melt. Since these magnesium oxides and the like are small amounts and are stable compounds, they do not adversely affect the quality of aluminum cast products.
[0027]
When the molten aluminum solidifies, the magnesium nitrogen compound deposited on the surface of the cavity removes oxygen from the oxide film on the surface of the molten aluminum to form pure aluminum. Is cast in a state where is not formed. By manufacturing the mold 12 so that the metal surface is exposed as it is on the surface of the cavity, the magnesium nitrogen compound generated on the surface of the cavity is retained on the surface of the cavity without disappearing, and the molten aluminum is removed. On the other hand, a reducing action can be reliably applied. Since the effect on the surface of the cavity has the greatest effect on the finish of the cast product, it is extremely important to ensure that magnesium nitrogen compounds are generated and retained on the surface of the cavity in order to obtain a good cast product. It is.
[0028]
Since the oxide film does not form on the surface of the molten aluminum due to the action of the magnesium-nitrogen compound generated on the surface of the cavity, the surface tension of the molten aluminum is reduced. The transferability (smoothness) is improved, and a high-quality aluminum cast product without hot water wrinkles or the like can be obtained.
[0029]
In this embodiment, nitrogen gas is introduced from the nitrogen gas cylinder 20 into the cavity in order to discharge air from the mold 12. However, an inert gas such as an argon gas is used instead of the nitrogen gas. You may. The air in the cavity is discharged in order to prevent the magnesium nitrogen compound generated in the cavity from reacting with oxygen as much as possible.
[0030]
The above embodiment is an example of casting by gravity casting. FIG. 4 shows another embodiment of the reduction casting method, in which the molding die 12 is formed by pressure casting composed of an upper die 50 and a pressing die 51. The casting method will be described. The molding die 12 has higher airtightness than the molding die used in the gravity casting method shown in FIG.
In the casting apparatus of this embodiment, a pipe 53 is branched in the middle of a pipe 22 connecting the nitrogen gas cylinder 20 and the molding die 12, a vacuum pump 52 is connected, and a valve 54 is provided in the middle of the piping 22. The inside and outside of the pipe 12 are connected by a pipe 55, and the pipe 55 is provided with a valve 56.
[0031]
When performing casting using the casting apparatus of the present embodiment, first, the valves 24 and 56 are closed, the valve 54 is opened, and the vacuum pump 52 is operated to make the inside of the mold 12 vacuum so that the mold 12 is While the inside of the cavity was set to a non-oxygen atmosphere, argon gas was introduced from the argon gas cylinder 25 into the heating furnace 28, and the valve 33 was opened to introduce argon gas into the tank 36. The magnesium powder is sent to sublimate the magnesium powder into magnesium gas. With the valves 54 and 56 closed, the valve 45 is opened and the magnesium gas is introduced into the mold 12 by argon gas.
Next, the valve 45 is closed, the valves 24 and 54 are opened, and nitrogen gas is introduced into the mold 12 from the nitrogen gas cylinder 20. When the nitrogen gas is introduced into the mold 12, the magnesium gas and the nitrogen gas react with each other, and powder of a magnesium nitrogen compound is generated on the inner surface of the cavity.
[0032]
In this state, the molten metal of aluminum is cast into a predetermined cavity shape by pushing up the pressing die 51. At the time of this casting, since the magnesium nitrogen compound is precipitated on the surface of the cavity formed by the inner surface of the upper die 50 and the pressing die 51, the surface of the molten aluminum is formed by the same operation as in the above-described embodiment. Casting can be performed while preventing formation of an oxide film.
[0033]
In the mold 12 of the present embodiment, the surface of the cavity is heat-treated to make iron tetroxide the surface of the mold. In the figure, reference numeral 12a denotes a processing film of a mold. Iron tetroxide does not react at all with the magnesium nitrogen compound generated on the surface of the cavity, so that the reducing action of the magnesium nitrogen compound is not impaired, and the action of reducing the oxide film formed on the surface of the molten aluminum is suitable. Works. As the processing of the molding die, it is also effective to perform a nitriding treatment in addition to the heat treatment. In this case, at the time of introducing the molten aluminum and at the time of pressure casting, the valve 56 is opened to facilitate introduction of the molten aluminum.
[0034]
FIG. 5 shows still another embodiment of a casting apparatus for separately introducing a magnesium gas and a nitrogen gas as metal gases into a mold 90 to generate a reducing compound in a cavity, and injecting a molten aluminum into the cavity to perform casting. The form is shown. The casting apparatus of this embodiment supplies a magnesium metal piece 100 to a heating furnace 28 as a vaporizer, melts magnesium in the heating furnace 28, and supplies the magnesium gas vaporized in the heating furnace 28 to the cavity of the mold 90. Is transmitted.
At the upper part of the heating furnace 28, there is provided a gas lock chamber 102 which is hermetically shut off from the outside air for storing the magnesium metal pieces 100, and drops the metal pieces 100 from the gas lock chamber 102 into the heating furnace 28 by an appropriate amount to supply. It is configured to Reference numeral 104 denotes a partition plate that opens and closes an opening at the bottom of the gas lock chamber 102. The metal pieces 100 are dropped into the heating furnace 28 by a predetermined amount from the gas lock chamber 102 by opening and closing the partition plate 104.
[0035]
Reference numeral 106 denotes an opening / closing lid for the gas lock chamber 102, which is opened / closed when the metal pieces 100 are refilled into the gas lock chamber 102. The gas lock chamber 102 is connected to the argon gas cylinder 25 and is provided with an exhaust pipe 108. Argon gas is supplied from the argon gas cylinder 25 and exhausted from the exhaust pipe 108, whereby the inside of the gas lock chamber 102 is replaced with argon gas. It is formed as follows. The gas lock chamber 102 and the heating furnace 28 need to have a non-oxygen atmosphere so that magnesium and oxygen do not react. After replenishing the gas lock chamber 102 with a certain amount of metal pieces (magnesium) 100, the open / close lid 106 is closed, and the gas lock chamber 102 is exhausted from the exhaust pipe 108 while flowing argon gas into the gas lock chamber 102, thereby closing the gas lock chamber 102. The inside of the gas lock chamber 102 can be made into a non-oxygen atmosphere by replacing with an argon gas.
[0036]
The metal pieces 100 dropped from the gas lock chamber 102 into the heating furnace 28 are melted in the heating furnace 28 and vaporized into magnesium gas. The method of transporting the magnesium gas from the heating furnace 28 to the cavity of the molding die 90 may be such that the argon gas is used as a carrier, and the valves 30 and 45 are opened to send the magnesium gas to the cavity of the molding die 90 as in the above-described embodiment. Of course, it is also possible to provide a flow rate control means for controlling the flow rate of the inert gas introduced into the heating furnace 28 and to control the flow rate of the magnesium gas sent from the heating furnace 28 to the cavity.
On the other hand, nitrogen gas is introduced from the nitrogen gas cylinder 20 into the cavity of the mold 90, whereby the magnesium gas and the nitrogen gas react inside the cavity to produce a magnesium nitrogen compound. In this state, a molten aluminum is poured into the mold 90 and cast.
[0037]
In the casting apparatus of the present embodiment, magnesium metal pieces 100 are supplied to a heating furnace 28 which is a vaporizer, and casting is performed in a state where magnesium is melted in the heating furnace 28 and a fixed amount of magnesium is always stored. . Since the magnesium gas is melted and stored, a required amount of magnesium gas can be supplied in accordance with the casting operation, and when the storage amount of magnesium decreases, replenish the magnesium metal pieces from the gas lock chamber 102. do it. By using the magnesium metal piece 100, it is possible to solve the problem that the magnesium powder may be sent to the mold 90 when the magnesium powder is used.
[0038]
In the casting apparatus described above, magnesium gas and nitrogen gas are separately introduced into the cavity of the mold, and the magnesium gas and nitrogen gas are reacted in the cavity to form a magnesium-nitrogen compound (Mg). ₃ N ₂ ) Is produced, and the magnesium nitrogen compound is caused to act on the molten aluminum to perform reduction casting.
FIG. 6 shows a process of producing a magnesium nitrogen compound in a cavity of a mold, injecting a molten metal into the cavity, and casting. In the figure, the horizontal axis indicates the elapsed time, and the vertical axis indicates the flow rate.
T (A) indicates the time when the mold is clamped, T (B) indicates the time when pouring has started, and T (C) indicates the time when pouring has ended. Graph A shows the control of the metal gas introduced into the cavity. The metal gas is introduced into the cavity using an inert gas such as an argon gas as a carrier. The metal gas is introduced into the cavity after clamping, and is introduced at a substantially constant flow rate until pouring is completed.
[0039]
Graph B shows the control of the reactive gas. B1 indicates that a method of introducing a nitrogen gas, an inert gas, or the like can be used to introduce a metal gas into the cavity so that the inside of the cavity is in a non-oxygen atmosphere. Graph C shows that an operation of reducing the pressure inside the cavity after introducing the metal gas is performed. When the metal gas starts to be introduced into the cavity, the pressure inside the cavity is reduced, so that the metal gas diffuses in the cavity and spreads evenly in the cavity. The depressurizing operation has a meaning that the metal gas is evenly distributed in the cavity so that the reducing compound is uniformly generated on the inner surface of the cavity when the reactive gas is introduced.
[0040]
Graph B2 shows that after reducing the pressure, a reactive gas such as nitrogen gas is introduced. By introducing the reactive gas, it reacts with the metal gas to generate a reducing compound in the cavity.
When a certain amount of the reactive gas has flowed in, the flow of the reactive gas is terminated, and the pouring starts. Since the reducing compound is generated in the cavity, the oxide film on the surface of the molten metal is cast while being reduced.
After the pouring is started, the metal gas is introduced until the pouring is completed because the outside air may enter together with the molten metal at the time of pouring. This is to ensure that the reducing action by the γ acts.
[0041]
【The invention's effect】
According to the metal gas generator according to the present invention, as described above, a metal gas that reacts with a reactive gas such as nitrogen gas to generate a reducing compound that reduces an oxide film formed on the surface of a molten metal is provided. It can be produced in a state where the outside air is shut off, and it is possible to easily transport metal gas to the cavity of the molding die, etc., and it is possible to cast by effectively using the reduction casting method in the reduction casting apparatus. And the like.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram showing a configuration example of a main part of a reduction casting apparatus according to the present invention.
FIG. 2 is an explanatory view showing an embodiment of a reduction casting apparatus.
FIG. 3 is a cross-sectional view and a front view showing a configuration of a connection port connected to a molding die.
FIG. 4 is an explanatory view showing another embodiment of the reduction casting apparatus.
FIG. 5 is an explanatory diagram showing a configuration example of a casting apparatus that supplies a metal piece to a vaporizer and performs casting.
FIG. 6 is a graph showing control of a magnesium gas, a nitrogen gas and the like introduced into a cavity of a molding die.
[Explanation of symbols]
10 Casting equipment
12 Mold
18 Melt
20 Nitrogen gas cylinder
22 Piping
25 Argon gas cylinder
28 heating furnace
32 heater
36 tanks
44 pipe
50 Upper mold
51 Press type
52 vacuum pump
60 First tank
65 Second tank
70 Evaporator
80 Flow control device
90 Mold
100 metal pieces
102 Gas lock room
104 Partition plate

Claims (6)

A metal gas generator used in a reduction casting apparatus for casting by reducing an oxide film on a surface of a molten metal by a reducing compound generated by reacting a metal gas and a reactive gas,
A first tank for storing the metal to be the metal gas,
A vaporizer for vaporizing the metal,
A second tank for storing an inert gas for introducing the metal into the vaporizer,
The first tank is branched from a middle of a pipe connecting the second tank and the vaporizer, and the first tank is connected so that the metal can flow into the pipe from the first tank. Metal gas generator. The first tank and the second tank are connected such that the first tank is pressurized by an inert gas stored in the second tank so that the metal can flow into the pipeline. The metal gas generator according to claim 1, wherein: A metal gas generator used in a reduction casting apparatus for casting by reducing an oxide film on a surface of a molten metal by a reducing compound generated by reacting a metal gas and a reactive gas,
A vaporizer for melting and vaporizing the metal that generates the metal gas,
A gas lock chamber that is installed in communication with the vaporizer at an upper portion of the vaporizer and that is kept airtight by shutting off outside air and stores the metal piece of the metal;
A metal gas generator, comprising: a partition plate for controlling the supply of the metal pieces from the gas lock chamber to the vaporizer by blocking communication between the vaporizer and the gas lock chamber. 4. The method according to claim 1, wherein an inert gas is introduced into the vaporizer as a carrier, and the metal gas vaporized in the vaporizer is introduced into a cavity of a molding die. Metal gas generator. 5. The metal gas generator according to claim 1, further comprising a flow controller for controlling a flow rate of the inert gas introduced into the vaporizer. The metal gas generator according to claim 1, 2, 3, 4, or 5, wherein magnesium is used as the metal.

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