JP2860256B2 - Adjustment method of initial base pressure in pressurized pouring furnace - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention generally relates to a pressurized pouring technique, and more particularly to a method for adjusting an initial base pressure in a pressurized pouring furnace provided with a pre-level position detecting device.

[0002]

2. Description of the Related Art For example, Japanese Patent Application Laid-Open No. 58-212857 discloses an example of a pressurized pouring furnace. This pressurized pouring furnace 1
A, as shown in FIG. 4 attached to the present application, melts a metal by induction heating, stores the molten metal A in a hot water storage chamber 201, and applies a predetermined pressure to the hot metal storage chamber 201 to throat the molten metal A. The molten metal is pushed up to the pouring chamber 203 via 202, and the molten metal that has passed the weir 204 is discharged from the tap hole 205.

More specifically, according to the pouring method using the pressurized pouring furnace 1A, as shown in FIG. 5A, an initial base pressure P ₀ is first applied to the hot water storage chamber 201. keep pushing up the molten metal level in the pouring chamber 203 to Purireberu position L ₁ given lower than this near the weir 204 Te.

[0005] Next, at the time of tapping, as shown in FIG.
Pushes up the molten metal level in the inner to pouring level L _2, weirs 2
The molten metal exceeding 04 is discharged from tap hole 205.

[0005] The base pressure P during pouring is controlled by the pouring pressure control device 10 in accordance with the output of the weight detector 206 indicating the amount of molten metal in the furnace in order to keep the level of molten metal in the pouring chamber 203 constant. It is controlled and gradually increases as the amount of molten metal decreases as shown in FIG.

[0006] When the molten metal A in the hot-water storage chamber 201 is reduced by tapping, for example, if molten metal previously melted in another induction melting furnace is received from the receiving port 207, pouring by pressurization can be continued.

Thus, the predetermined pre-level position L ₁
Is a reference height when pushing up the melt to pouring level L ₂ by applying a certain shot pressure △ P, also the initial base pressure P ₀ determined by Purireberu position L ₁ before starting pressurized insufflation hot water , since the reference pressure of the base pressure P gradually increasing with decreasing melt a of the hot water storage chamber 201, Purireberu position L ₁ is controlled on the important role of pressure injection water.

For this reason, when starting the pressurized pouring, the initial base pressure P ₀ for raising the molten metal A in the hot water storage chamber 201 to a predetermined pre-level position L ₁ must be adjusted visually or by an appropriate method using a jig or the like. Although it is necessary, once the adjustment is performed at the time of starting the pressurized pouring, the operation can be continued by receiving the supply of the molten metal from the hot water receiving port 207 at any time. Therefore, there is no need to readjust until the base pressure P is released.

However, such a pressurized pouring furnace 1A
As shown in the figure, it is a grooved induction furnace, it is necessary to always fill the groove with molten metal at startup and operation,
Not all hot springs are possible. Furthermore, this pressurized pouring furnace 1A
Throat (pouring siphon) 20 communicating with hot water storage room 201
2 and the hot-water siphon 208 having the hot-water inlet 207 must be integrally formed, and the furnace construction takes time. or,
Since the heating unit is concentrated on the inductor, there are various problems that the life is short, and therefore, the heating unit needs to be configured to be detachable from the hot water storage chamber 201 and to be frequently replaced.

Therefore, as a means for solving the above problem,
As described in JP-A-3-66468, a pressurized pouring furnace provided with a coreless crucible type induction furnace has been proposed. As shown in FIG. 7 attached to the present application, this pressurized pouring furnace 1B has a coreless crucible-type induction furnace 210 detachably housed in an airtight container 212 having an airtight cover 211. The pouring pressure pipe 213 for applying the pouring pressure of the control device 10 is connected. The lower end of the airtight cover 211 is located below the induction furnace 210, that is, the crucible 210a.
Pouring chamber 214 with an opening at the bottom and a pouring nozzle at the top
Pouring siphon 215 and crucible 210 at the lower end
A pouring siphon 217 having an opening at the bottom in FIG.

In the pressurized pouring furnace 1, the airtight cover 21
1 from the pouring pressure pipe 213 provided above
By applying pressure into the inside 2, the molten metal is pushed up to the pouring chamber 214 through the pouring siphon 215, and is discharged from the pouring nozzle 218 at the other end of the pouring chamber 214.

The principle and operation of the pressurized pouring furnace 1B are the same as those of the pressurized pouring furnace 1A of the above-mentioned grooved induction furnace. From the position, an initial base pressure P ₀ is determined, and pouring is started by applying a shot pressure ΔP.
The base pressure P is gradually increased with a decrease in the amount of molten metal in 10a,
When the amount of molten metal A in crucible 210a decreases, molten metal replenishment from molten metal receiving chamber 216 can be repeated to continue pressurized molten metal pouring.

[0013]

On the other hand, the present inventors have
We have proposed an induction furnace that combines vacuum melting and pressurized pouring to minimize the oxidation of active metals contained in the melting of alloys containing active metals and to discharge hot water without involving unavoidably generated slag. No. 6-113879).

As shown in FIG. 1 of the present application, the vacuum melting / pressure pouring / induction furnace includes an airtight container 5 containing an induction melting furnace 4 having a crucible 2 and a heating coil 3, and a vacuum exhaust pipe. A pouring siphon 20 having a vacuum melting furnace lid (not shown) and a pouring pressure pipe 7, a lower end opening to the bottom of the induction melting furnace 4 and a pouring chamber 31 with a pouring nozzle connected to the upper end. And a furnace lid 6 for pressurized pouring.

In the induction furnace 1 for vacuum melting and pressurized pouring having such a structure, first, the upper end of the hermetic vessel 5 is sealed with a furnace lid for vacuum melting, and the inside of the hermetic vessel 5 is evacuated to vacuum. The raw materials are vacuum-dissolved inside. When a predetermined amount of melting is completed, the pressure inside the airtight container 5 is once restored to the atmospheric pressure, and the furnace lid for vacuum melting and the furnace lid 6 for pressure pouring are exchanged, as shown in FIG. At 6, the airtight container 5 is sealed again. Next, pressure is applied from the pouring pressure pipe 7 into the airtight container 5 to push up the molten metal in the induction melting furnace 4 to the pouring chamber 31 via the pouring siphon 20, and pouring the other end of the pouring chamber 31. Hot water is discharged from the nozzle 33. At this time, the slag S, which is inevitably generated even when vacuum melting is performed, is floating on the surface of the molten metal in the furnace.
The slag S can be taken out of the molten metal A without being entangled.

However, in the induction furnace 1 for both vacuum melting and pressure pouring, melting and pressure pouring are alternately performed in the same induction melting furnace. The initial base pressure must be adjusted each time from a predetermined pre-level position each time the pressure is poured after replacement. In addition, the initial base pressure, the amount of melting differs for each charge, or the volume of the furnace gradually decreases due to slag deposited on the furnace bottom and the furnace wall each time melting is repeated. Since the subsequent actual hot water level gradually increases, it is necessary to strictly adjust the initial base pressure for each charge.

However, when the molten metal is an alloy containing an active metal, the oxidation proceeds immediately when the molten metal is exposed to the atmosphere. It is sealed and filled with an inert gas to create an inert atmosphere. Further, the pouring chamber 31 is sufficiently heated in advance to prevent the temperature of the molten metal pushed up from dropping. Therefore, the pouring siphon 20 is placed at the top of the pouring chamber 31.
It is difficult to check the pre-level height by looking into the inside or inserting a jig or the like each time.

Accordingly, it is an object of the present invention to easily and accurately detect the arrival of a molten metal rising in a pouring siphon communicating with an induction melting furnace to a pre-level position, and furthermore, to perform pressurized injection. It is an object of the present invention to provide a method of adjusting an initial base pressure of a pressurized pouring furnace with a pre-level position detecting device, which can supply hot water with an accurate amount of hot water.

[0019]

The above object is achieved by a method for adjusting an initial base pressure of a pressurized pouring furnace with a pre-level position detecting device according to the present invention. In summary, the present invention provides:
An induction melting furnace housed in an airtight container capable of being pressurized within a desired maximum allowable pressure, a pressure pipe for applying a pouring pressure controlled by a pouring pressure control device into the airtight container, and a lower end provided with the An airtight furnace lid that is open at the bottom of the induction melting furnace and has a pouring siphon connected to a pouring chamber with a pouring nozzle at the upper end, and an airtight furnace lid that penetrates the pouring siphon from the top of the pouring chamber. The lower end of the conductor rod is located at a predetermined pre-level position, and by pressurizing the inside of the hermetic container containing the induction melting furnace sealed with the hermetic furnace lid. The molten metal in the induction melting furnace rises in the pouring siphon, forms an electric circuit when the molten metal contacts the lower end of the conductor rod, and the molten metal rising in the pouring siphon reaches a pre-level position. First pressurized pouring furnace to detect It relates to the modulation method of the base pressure.

In particular, the method of adjusting the initial base pressure of the pressurized pouring furnace of the present invention is a method of adjusting the initial base pressure of the molten metal by closing the airtight furnace lid and pressurizing the inside of the airtight container containing the induction melting furnace storing the molten metal. Is raised in the pouring siphon, and when the molten metal contacts the lower end of the conductor rod to form an electric circuit, the increase in the applied pressure in the airtight container is stopped, and the control of the pressure control device at that time is stopped. Subtracting a predetermined pressure value from the signal pressure value, holding the reduced control signal pressure value as an initial base pressure, determining and maintaining the height of the molten metal level in the pouring siphon as a predetermined pre-level position; It is characterized by.

According to a preferred embodiment of the present invention, the pressure applied to the hermetic container is controlled by a pressure control device so that the molten metal is automatically raised into the pouring siphon.

Further, in the method of the present invention, the pressure in the airtight container is increased to detect the pre-level position, and if the electric circuit is not formed even if the pressure is increased to a predetermined pressure, the airtightness is immediately determined. It is preferable to have an abnormal stop function for exhausting the pressure applied to the container.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A method for adjusting an initial base pressure of a pressurized pouring furnace with a pre-level position detecting device according to the present invention will be described in more detail with reference to the drawings.

First, an embodiment of a pressure type pouring furnace according to the present invention will be described with reference to FIG.

In FIG. 1, as described above, a pressurized pouring furnace 1 comprises, for example, a coreless crucible type induction furnace having a crucible 2 made of a refractory material and an induction heating coil 3 arranged on the outer periphery thereof. An induction melting furnace 4 and a hermetic container 5 for accommodating the induction melting furnace 4 are provided. The upper part of the hermetic container 5 is closed by a hermetic furnace lid 6.

The induction melting furnace 4 in the hermetic vessel 5 can melt and hold the metal raw material charged with the hermetic furnace lid 6 opened. After melting the metal raw material, the airtight container 5
Is hermetically closed by an airtight furnace lid 6. If the metal to be melted is an alloy containing an active metal, the upper part of the hermetic container 5 containing the induction melting furnace 4 is closed with a vacuum melting furnace lid (not shown) equipped with a vacuum exhaust device, and the inside of the hermetic container 5 It is also possible to perform vacuum melting in a state of evacuation. If melted in vacuum,
Once the inside of the airtight container 5 is replaced with an inert gas, the furnace lid for vacuum melting is released and moved to the standby position, and the airtight furnace cover 6 is moved to the upper part of the airtight container 5 to seal the airtight container 5.

The metal raw material is melted and held in the atmosphere or in a vacuum state, and the inside of the airtight container 5 sealed with the airtight furnace lid 6 is controlled by a pouring pressure control device 10 preferably with an inert gas such as argon gas. Is introduced, and can be pressurized to a desired maximum allowable pressure, for example, a maximum of 0.98 kg / cm ² .

In the crucible 2, a pipe-shaped pouring siphon 20 is installed substantially vertically in this embodiment. Although the pouring siphon 20 is made of pipe-shaped carbon in the present embodiment, it can be made of another material. With such a configuration, the lower end 20a of the pouring siphon 20
Is open at the bottom of the crucible 2, while the pouring siphon 20
The upper end 20b is connected to one end 30a (the right end in FIG. 1) of a pouring gutter 30 that defines a pouring chamber 31 installed substantially horizontally, and opens to the pouring chamber 31. A pouring nozzle 33 is provided at the other end 30b (the left end in FIG. 1) of the pouring gutter 30. Pouring gutter 30 is a heating device (not shown) for maintaining the temperature of the molten metal transferred to pouring chamber 31 at an appropriate temperature.
Is preferably provided.

According to the present invention, in the pressurized pouring furnace having the above structure, pouring siphon 2
The conductor bar 50 is disposed by inserting the conductor bar 50 into the conductor rod 50. The conductor rod 50 is adjusted so that its lower end 50a is located at a predetermined pre-level position.
1 is maintained in an electrically insulated state. In this embodiment, the conductor rod 50 is made of carbon, and the insulating holder 51 is attached to the sealing lid 32 that seals the upper part of the pouring chamber 31.
Mounted through. The conductor bar 50 is not limited to carbon, and any material can be appropriately selected and used.

According to the present invention, between the conductor rod 50 and the molten metal A, the molten metal which rises in the pouring siphon 20 by applying pressure to the airtight container 5 is filled with the molten metal A.
It is configured to form the electric circuit 100 when contacting the lower end 50a of the zero. That is, for example, as shown in FIG. 1, the power supply 101 and the pre-level detector 1 are disposed between the carbon conductor rod 50 and the carbon pouring siphon 20.
02 are connected in series. Therefore, pouring siphon 2
When the molten metal that has risen inside 0 comes into contact with the conductor bar 50,
When the molten metal surface reaches the pre-level position, the conductive bar 50 and the pouring siphon 20 are electrically energized, the electric circuit 100 is activated, and the pre-level detector 102 emits a signal. If the pouring siphon 20 is made of an electrically insulating material such as a refractory material, an electric conductor piece is disposed at the bottom of the crucible 2 and an electric circuit is provided between the conductor piece and the conductor rod. May be formed.

According to the present invention, at the start of pouring, before the inside of the airtight container 5 is pressurized, the conductor bar 50 is connected to the pouring siphon 20.
It is inserted into the predetermined position. Then, as described above,
Injection pressure control device 10
And the inside of the airtight container 5 is pressurized. Thereby, the molten metal A rises inside the pouring siphon 20, and when the molten metal contacts the lower end portion 50a of the conductor rod, the electric circuit 100 is formed. Then, the pre-level detector 102 operates,
The operator or the pouring pressure control device 10 is notified that the applied pressure (ie, the base pressure P) has reached the pre-level state (ie, the initial base pressure P ₀ ). Therefore, the worker or the pouring pressure control device 10 stops increasing the applied pressure into the airtight container 5, maintains the applied pressure state at this time until pouring is started, and outputs a pouring start signal. As a result, a shot pressure ΔP having a predetermined magnitude is further applied to the airtight container 5.
Thereby, the molten metal A in the crucible 2 is poured into the pouring siphon 2
The temperature is further raised to 0 and fed to the pouring chamber 31 of the pouring gutter 30, and the hot water is discharged from the pouring nozzle 33.

The adjustment of the initial base pressure in the present invention is performed by increasing the pressure applied to the airtight container 5 by using the pouring pressure control device 1.
It can be controlled automatically by 0 and performed automatically.

According to the present embodiment, the pouring pressure control device 10 is set so as to increase the base pressure by 0.01 kg / cm ² every 5 seconds by operating a switch on the operation panel. As described above, the molten metal A in the crucible 2 is poured into the pouring siphon 20 by the applied pressure that is increased by a constant pressure at regular intervals.
When the electric circuit 100 rises inside and comes into contact with the lower end 50a of the conductor rod 50, the applied pressure is in a pre-level state,
That is, it is detected that the initial base pressure P ₀ has been reached. Therefore, by holding this applied pressure at the time of detection,
Adjustment of the initial base pressure for maintaining the level of the molten metal in the pouring siphon at a predetermined pre-level position can be performed automatically.

In the above description, when the pre-level detector 102 operates, the applied pressure state at this time is maintained until the pouring operation is started. However, according to the present invention, the inside of the pouring siphon 20 is maintained. The molten metal that has risen
When the electric circuit 100 is formed in contact with the lower end 50a of the zero, the increase in the pressure applied to the airtight container 5 is stopped, and the predetermined pressure value is subtracted from the control pressure value of the pouring pressure control device at that time. The reduced control pressure value is held as the initial base pressure, and the level of the molten metal in the pouring siphon 20 is determined and maintained at the predetermined pre-level position. Next, a further description will be given with reference to FIGS.

FIG. 2 shows the relationship between the control signal pressure and the actual furnace pressure when the pressure applied to the airtight container 5 is automatically controlled by the pouring pressure control device 10. In the present embodiment, the control signal pressure is controlled so as to increase stepwise by 0.01 kg / cm ² every 5 seconds. It can be seen that it increases almost linearly.

As described above, the control of the pressure applied to the inside of the airtight container 5 is performed by the pouring pressure control device 10. More specifically, the pressure supplied from the pouring pressure control device 10 is supplied. The pressure control valve (not shown) opens and closes according to the control signal pressure, and the pressure applied to the airtight container 5 is adjusted. Also, when pressure is applied to the airtight container 5 to raise the molten metal in the induction melting furnace into the pouring siphon 20, usually,
The applied pressure is increased by gradually increasing the control signal pressure by operating a variable volume or the like.

However, the pressure difference between the control signal pressure value supplied from the pouring pressure control device 10 to the pressure control valve and the output pressure from the pressure control valve, that is, the actual furnace pressure in the hermetic vessel 5 has a differential pressure. Occurs. In particular, when increasing the pressure, there is a delay in increasing the in-furnace pressure with respect to the increase in the control signal pressure. Therefore, even if the increase of the control signal pressure is stopped when the molten metal surface rising inside the pouring siphon 20 comes into contact with the lower end 50a of the conductor bar 50, and the control signal pressure value at that time is maintained, the furnace pressure is maintained. , And further increases to a pressure obtained by subtracting the unavoidable differential pressure from the held control signal pressure value, and finally the lower end 50 a of the conductor rod 50 in the pouring siphon 20.
Is maintained at a position beyond That is, the already applied furnace pressure at which the molten metal level has been raised to a position beyond the predetermined pre-level position is determined as the initial base pressure.

Therefore, when the shot pressure is further applied thereafter, the height of the molten metal in the pouring chamber 31 rises above a predetermined height, and is determined by the hole diameter of the pouring nozzle 33 and the height of the molten metal in the pouring chamber 31. The actual pouring amount is increased by the predetermined pouring amount.

As shown in FIG. 2, when the molten metal that has risen in the pouring siphon 20 comes into contact with the lower end 50a of the conductor bar 50, the control signal pressure P has already exceeded the initial base pressure P ₀ determined at a predetermined pre-level position. It is understood that. Therefore, when the electric circuit 100 is formed and the control signal pressure P at that time is held, the actual furnace pressure after the elapse of a predetermined time, the following delay with the maintained control signal pressure P is eliminated, Pressure value P ₀ 'corresponding to this control signal pressure P
(Pressure value obtained by subtracting the unavoidable differential pressure dP from the control signal pressure P) (P ₀ ′> P ₀ ). Since the height of the molten metal rising in the pouring siphon 20 is determined by the actual furnace pressure, the molten metal in the pouring siphon 20 also has a pressure P ₀ ′.
It rises further to the height suitable for. That is, the pre-level position is maintained higher than the predetermined pre-level position.

In order to solve such a problem, the molten metal which has risen in the pouring siphon 20 has a lower end 50 a of the conductor rod 50.
When the pouring pressure control device 10 reduces and retains a certain pressure reduction value P ′ in consideration of the following delay in the furnace pressure and the unavoidable differential pressure dP from the control signal pressure in advance from the control signal pressure, as shown in FIG. the actual furnace pressure is correctly adjusted to the initial base pressure P ₀ determined by the predetermined Purireberu position, the molten metal in the pouring siphon 20 is maintained correctly to a predetermined Purireberu position. That is, it can be adjusted as an accurate initial base pressure, and then a predetermined pouring amount can be obtained by further applying a shot pressure.

It is preferable that the present invention is provided with an abnormal stop function. That is, as described above, when the pressure is applied to the hermetic container 5 and the electric circuit 100 is not formed even when the pressure is continued to be applied, the abnormal stop function is immediately performed to detect the pre-level position. It operates to exhaust the pressure P applied to the container.

That is, the abnormal stop function is provided by the airtight container 5.
Is storing the amount of molten metal determined from the capacity of the crucible 2 , for example, when the initial base pressure P ₀ determined from a predetermined pre-level position is about 0.05 kg / cm ² , for example, into the airtight container 5. The applied pressure is 0.2kg / cm
^{When the} electric circuit 100 is not formed even after reaching ^2, the conductor bar 5 inserted and installed in the pouring siphon 20 is used.
It operates to exhaust the applied pressure assuming that there is some abnormality in 0.

By providing such a means, for example, when the conductor bar 50 is inserted into the pouring siphon 20 from above the pouring chamber 31, the conductor bar 50 is damaged, and for example, the length of the conductor bar 50 is defined. Even when pressure is applied to the airtight container 5 without noticing that the length becomes extremely shorter than the length, the molten metal rising in the pouring siphon 20 exceeds the pre-level position and further rises into the pouring chamber 31. It is possible to prevent such an abnormal situation as before.

In the description of the above embodiment, the pressurized pouring furnace 1 has been described as including the ironless crucible type induction furnace. However, the induction melting furnace is not limited to this in the present invention. Instead, any other type of induction melting furnace can be used.

[0045]

As is apparent from the above description, the method for adjusting the initial base pressure in the pressurized pouring furnace with the pre-level position detecting device according to the present invention is applied to an airtight container that can be pressurized within a desired maximum allowable pressure. It is provided with a housed induction melting furnace, and a pressure pipe for applying a pouring pressure controlled by a pouring pressure control device into the hermetic container, and a lower end is opened at a bottom of the induction melting furnace, and a pouring is performed at an upper end. An airtight furnace lid that penetrates a pouring siphon connected to a pouring chamber with a nozzle, and a conductor rod is arranged by inserting the pouring siphon from above the pouring chamber into the pouring siphon; The lower end is located at a predetermined pre-level position, and the molten metal in the induction melting furnace flows through the pouring siphon by pressurizing the inside of the hermetic container housing the induction melting furnace sealed with the hermetic furnace lid. Ascends and the molten metal is An electrical circuit formed when in contact with,
A method for adjusting an initial base pressure of a pressurized pouring furnace for detecting that the molten metal that has risen in the pouring siphon has reached a pre-level position, wherein the induction melting is performed by closing the hermetic furnace lid and storing the molten metal. The molten metal is raised into the pouring siphon by pressurizing the inside of the hermetic container containing the furnace, and when the molten metal contacts the lower end of the conductor rod and an electric circuit is formed, the applied pressure in the hermetic container is increased. Is stopped, a predetermined pressure value is subtracted from the control signal pressure value of the pressure control device at that time, the reduced control signal pressure value is held as an initial base pressure, and the height of the molten metal level in the pouring siphon is maintained. Is determined and maintained as a predetermined pre-level position,
It is possible to easily and accurately detect that the molten metal in the pouring siphon communicating with the induction melting furnace has reached a predetermined pre-level position, and to discharge the molten metal with an accurate pouring amount by pressurized pouring. be able to.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing one embodiment of a pressurized pouring furnace with a pre-level position detecting device according to the present invention.

FIG. 2 is a graph showing an example of a control signal pressure pattern and a change in furnace pressure in a pressurized pouring furnace.

FIG. 3 is a graph showing another example of a control signal pressure pattern and a change in furnace pressure according to the present invention.

FIG. 4 is a schematic sectional view of a pressurized pouring furnace of a conventional grooved induction furnace.

FIG. 5 is a schematic sectional view showing a method of adjusting an initial base pressure and a method of pressurizing the pressurized pouring furnace of the grooved induction furnace of FIG.

FIG. 6 is a graph showing an example of a pouring pattern of a pressurized pouring furnace.

FIG. 7 is a schematic sectional view of a pressurized pouring furnace provided with a conventional ironless crucible type induction furnace.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Pressurized pouring furnace 2 Crucible 3 Induction heating coil 4 Induction melting furnace 5 Airtight container 6 Airtight furnace lid 10 Pouring pressure control device 20 Pouring siphon 30 Pouring gutter 31 Pouring chamber 33 Pouring nozzle 50 Conductor rod 100 Electricity circuit

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Akio Kaneshiro 1-1-1, Tanabe-Nitta, Kawasaki-ku, Kawasaki-shi, Kanagawa Prefecture Inside Fuji Electric Co., Ltd. (56) References JP-A-55-97866 (JP, A) Hei 3-281059 (JP, A) JP-A-63-90355 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) B22D 39/06 F27B 14/06 F27D 21/00

Claims (3)

(57) [Claims] 1. An induction melting furnace, comprising: a pressure pipe for applying a pouring pressure controlled by a pouring pressure control device into the hermetic container; and a lower end opening to a bottom of the induction melting furnace.
An airtight furnace lid having a pouring siphon connected to a pouring chamber with a pouring nozzle at an upper end thereof is provided, and a conductor rod is disposed by being inserted into the pouring siphon from above the pouring chamber. The lower end of the conductor rod is located at a predetermined pre-level position, and the inside of the induction melting furnace containing the induction melting furnace sealed with the hermetic furnace lid is pressurized to melt the molten metal in the induction melting furnace. The initial stage of the pressurized pouring furnace which rises in the hot water siphon, forms an electric circuit when the molten metal contacts the lower end of the conductor rod, and detects that the molten metal rising in the pouring siphon reaches the pre-level position. A method for adjusting a base pressure, wherein the molten metal is raised into the pouring siphon by closing the airtight furnace lid and pressurizing an airtight container containing the induction melting furnace storing the molten metal. Touch the lower end of the conductor bar When the air circuit is formed, the increase in the applied pressure in the hermetic container is stopped, a predetermined pressure value is subtracted from the control signal pressure value of the pressure control device at that time, and the reduced control signal pressure value is initialized. A method for adjusting an initial base pressure in a pressurized-type pouring furnace, wherein the initial base pressure is maintained as a base pressure, and the height of the molten metal level in the pouring siphon is determined and maintained at a predetermined pre-level position. 2. A pressurized pouring furnace according to claim 1, wherein an increase in pressure applied to said airtight container is controlled by a pressure control device to automatically raise molten metal into said pouring siphon. Adjustment method of initial base pressure in 3. The pressure in the hermetic container is increased when the pressure in the hermetic container is increased to detect a pre-level position and the electric circuit is not formed even when the pressure is increased to a predetermined pressure. The method for adjusting an initial base pressure in a pressurized-type pouring furnace according to claim 1 or 2, wherein the method has an abnormal stop function of exhausting gas.