JPH0763834B2 - Molten metal hot water supply method and hot water supply apparatus using bias control method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention quantitatively supplies molten metal in a holding furnace holding molten metal to a supply facility outside the holding furnace by pressurizing the molten metal in the holding furnace. The present invention relates to a molten metal hot water supply method and a hot water supply device.

[Prior Art and Problems Thereof] Various inventions and inventions have been conventionally made regarding a pressurized hot water supply furnace.

For example, JP-A-48-7843, JP-A-63-40661, and Japanese Patent Application No. 63-16854.
6, Japanese Patent Application 63-307126, Japanese Patent Application 1-90231, etc.
The method / apparatus based on 48-7843 has been widely put into practical use and spread all over the world including Japan.

However, recent demands for technological development and improvement have become more and more stringent, and demands for accuracy of hot water supply and reduction of probability of trouble (that is, reduction of opportunity loss) have become particularly strict.

From such a point of view, the above-mentioned JP-A-63-40661, JP-A-48-7843, and Japanese Patent Application No. 63-168 shown in FIGS.
The methods and devices based on 546 and Japanese Patent Application No. 63-307126 have common weak points.

That is, in those methods, a valve such as a solenoid valve is used in one of two measuring chambers such as a diaphragm inside a pressure transmitter as a method of storing the pressure inside the furnace when a sensor such as an electrode detects molten metal. The method of containment is used.

Then, the pressure increase amount after the detection of the molten metal by the sensor is recognized as a differential pressure and controlled.

In this case, since the amount of gas that can be enclosed in the measurement chamber using a valve such as a solenoid valve is a limited small amount, variations due to the operating conditions of the valve (for example, valve operation delay, valve body movement, etc.) will cause an absolute error. Inevitably, the accuracy of the amount of hot water supply was limited to ± 2 to 3%.

In addition, dividing the pipeline of the furnace pressure conduit around the pressure transmitter,
A fairly fine pipe line was formed by incorporating a valve in the middle of the pipe, and troubles due to behavior such as clogging, leakage, and water drop dust in the pipe line were also seen.

Similarly, in practice, the valve is opened and closed at a frequency of 3 times per minute, and the probability of failure from this point cannot be neglected.
Further, in order to improve productivity, the frequency of opening and closing this valve must be increased, and from this point also, there is a limit to improving productivity, that is, increasing the operating cycle.

Further, basically, it is better to exclude parts that require mechanical operation as much as possible in the entire device.

The flow chart shown in FIG. 5 shows the concept of the molten metal hot water supply method relating to Japanese Patent Application No. 1-90231. In this method, the above-mentioned Japanese Patent Laid-Open Nos. 48-7843 and 63-40661,
Although the common weak points of the methods / apparatuses based on Japanese Patent Application No. 63-168546 and Japanese Patent Application No. 63-307126 were almost overcome, the input signal was once output as an external output value in the bias control device and was again output to the remote input section. Since it is taken in and used as the basic value of the control set value, it is extremely rare but causes a delay due to timing deviation or a delay due to a connection failure, and it is set as the control set value and set in the comparison calculation unit. At the time of comparison, it has already been found that the measured value may overtake the control set value and become a singular value outside the control range in practical use, and there is a limit to the strict and highly accurate required specifications.

[Object of the Invention] In view of the above problems of the prior art, the present invention further improves hot water supply accuracy, has less failure frequency, has a small number of parts, and enables high cycle, and further improves productivity. It is an object of the present invention to provide a molten metal hot water supply method and a hot water supply device that can meet more advanced and strict requirements.

[Means for Solving Problems] Hereinafter, an embodiment of the present invention will be described.

(1) FIG. 1 is a flowchart showing the concept of a molten metal hot water supply method using a bias control method according to the claims.

The basic start of the molten metal hot water supply method using the bias control method according to the present invention is as follows. First, the bias value is input and set via the bias value external setting device of the bias control device, and the inside of a control panel (not shown) is set. The hot water supply timer incorporated with the bias control device, the temperature control device (not shown), or various types of stability protection devices
It starts by inputting and setting the timer value from 15 seconds to 15 seconds.

When the initial data of the bias value and the timer value are set, the system in the present invention is in a standby state for a hot water supply command from a molten metal supply device such as a die casting machine, a die casting machine, a sand casting machine.

When a control panel (not shown) receives a hot water supply command from the supplied device, pressurization of the pressurizing hot water supply furnace is started.

FIG. 2 is a conceptual cross-sectional view relating to an embodiment of the claims. The concept of the claimed invention will be described with reference to FIG.

If the holding furnace 3 is pressurized with gas, the molten metal 5 rises in the hot water supply pipe 4.

In this way, when the pressurization by the gas to the pressurized hot water supply furnace is started, the pressure in the holding furnace 3 is measured by the pressure sensor 2 and is necessary for conversion into a digital signal in the A / D converter by the amplifier. Amplified to various levels, transmitted to the A / D converter, data is transmitted to the furnace pressure measurement value input section of the bias control device, and the molten metal rises in the hot water supply pipe 4 attached to the holding furnace 3. I will do it.

The measured value received by the measured value input unit is detected by the molten metal detection signal input unit by detecting the metal melt rising in the hot water supply pipe 4 by the electrode 7 installed at the fixed position of the hot water supply pipe 4. It is only repeatedly received as data until it is recognized by the molten metal detection determination unit, but the electrode 7 detects the rising metal molten metal in the hot water supply pipe 4,
Once transmitted to the molten metal detection determination unit via the molten metal detection signal input unit, the measured value received immediately after that is stored in the data register, and the preset bias value is added to control. It is transmitted to the value comparison calculation unit.

Even after that, the pressure measurement data in the holding furnace 3 that is repeatedly received is transmitted as a comparison calculation measurement value to the control value comparison calculation section by the data storage determination section because the data is already stored in the data register, and comparison calculation is performed. It

Since the electrode 7 pressurizes the inside of the holding furnace 3 even after detecting the molten metal in the hot water supply pipe 4, the molten metal flows out of the outlet 42.
Overflows from.

The comparison calculation measurement value is repeated until the comparison calculation measurement value reaches the control set value, and the control output unit issues a command to stop the pressurization to stop the pressurization.

At the same time as the pressurization is stopped, the hot water supply timer is started, and after the preset timer time has elapsed, the time is up, the internal pressure of the furnace is discharged, and the supply of molten metal is stopped.

Regarding the amount of pressure increase in the pressurizing type hot water supply furnace after detection of molten metal at the fixed point of the hot water supply pipe and the realization of quantitative hot water supply within a fixed time after stopping the pressure increase, refer to (7) of Patent Document 64-6870. As described, it can be said to be clear by the study by the inventors of the present invention.

In this way, when hot water supply is completed, a control panel (not shown) initializes the control conditions other than the bias value and the hot water supply timer value input as initial data, and again enters the standby state for the hot water supply command from the device to be supplied. .

After this, hot water supply is repeated based on the hot water supply command from the supplied device, but the furnace pressure that fluctuates every time the molten metal reaches the hot water supply pipe fixed point is reliably and accurately captured, and the hot water supply pipe fixed point is The absolute value control of the pressure increase amount in the pressurized hot water supply furnace after passing is performed every time, and a highly accurate hot water supply method is realized.

(2) FIG. 2 is a conceptual sectional view related to the claims.
In the figure, the heat insulation furnace 3 is a heating source such as a rod-shaped resistance heating element.
A temperature control device (not shown) in the hot water supply device control panel controls the temperature of the molten metal 5 measured by the thermocouple in the thermocouple protection tube 8 to be constant.

Further, the hot water supply pipe 4 is immersed in the molten metal 5 held in the holding furnace 3 and has an inflow port 41 for the molten metal, and supplies it to a supplied device such as a die casting machine not shown outside the furnace. Outlet 42 for molten metal at a position in contact with the hot water supply gutter 6
By contacting the outlet 42 with the molten metal 5 that has risen in the hot water supply pipe 4, the conductivity is maintained by immersing the molten metal 5 in the holding furnace 3 inside and holding the thermocouple therein. An electrode 7 having a role as a positive electrode capable of detecting a molten metal by being energized with a thermocouple protection tube 8 having a role as a negative electrode is mounted.

The holding furnace 3 has an opening 27 for cleaning and inspecting the inside, receiving a molten metal from the outside, and a lid 28 for sealing the opening 27, and the opening 28 is opened if necessary. The work is performed using the part 27, and the holding furnace 3 is sealed during operation.

Further, the holding furnace 3 is connected to a pressure source 17 such as compressed air or an inert gas cylinder on a side wall or a ceiling portion at a position higher than the holding position when the maximum amount of the molten metal 5 is held, and opens and closes a pipeline in the middle. Equipped with a pressure port 10 to which a pressure pipe 13 equipped with a pressure valve 15 of is connected, and equipped with an exhaust valve 16 that is opened to the outside atmosphere to discharge the internal pressure and opens and closes the pipeline halfway Has an exhaust port 11 connected to an exhaust pipe 14 and connects to a pressure measuring pipe 12 connected to the measuring port of a pressure transmitter 2 for measuring the pressure in the holding furnace 3 and transmitting the measured value to the bias control device 1. The pressure measuring port 9 is provided.

The bias control device is installed in a hot water supply device control panel (not shown), and has the above-mentioned thermocouple protection tube 8 having a role of a negative pole, an exhaust valve 16, a pressurizing valve 15,
The pressure sensor 2, the amplifier 51, the A / D converter 52, and the electrode 7 as a positive electrode are electrically connected. The bias value of the initial data is input and set in the bias control device 1, the hot water supply timer value is input and set in the hot water supply timer in the hot water supply device control panel (not shown), and the hot water supply command is issued from the supplied device (not shown). When received by a hot water supply device control panel (not shown), the inside of the holding furnace 3 is pressurized by inflow of gas from the pressure source 17 through the pressure valve 15 and the pressure pipe 13 through the pressure port 10.

When the inside of the holding furnace 3 is pressurized, the molten metal 5 flows into the hot water supply pipe 4 through the molten metal inlet 41, and the pressure inside the holding furnace 3 is the pressure measuring pipe connected to the pressure measuring port 9. It is measured at any time via the pressure sensor 2 via 12, amplified by the amplifier 51, converted as a digital signal by the A / D converter 52, and transmitted to the bias controller.

Thus, as described in the description (1) of the claims, the holding furnace 3 is made up of the molten metal 5 by the positive electrode 7.
Absolute value control of the amount of pressure increase after is detected, the pressurizing valve 15 installed in the middle of the pressurizing pipe 13 is closed and pressurization is stopped, and the hot water supply device control panel (not shown) After the time for the hot water supply timer has expired, the exhaust valve 16 provided in the exhaust pipe 14 is opened, the pressure in the holding furnace 3 returns to atmospheric pressure, and the rising molten metal 5 in the hot water supply pipe 4 is placed in the holding furnace 3. Returning from the inflow port 41 of the molten metal, the hot water supply through the hot water supply gutter 6 to the supply target device (not shown) is completed.

Thus, as described in the description (1) of the claims, the hot water supply apparatus according to the claims uses the molten metal hot water supply method using the bias control method, so that the hot water supply with high repeatability and less troubles can be performed in a high cycle. It is established as a device that realizes hot water supply.

(3) FIG. 3 is a conceptual sectional view related to the claims.
In the figure, the heat insulation furnace 3 is a heating source such as a rod-shaped resistance heating element.
A temperature control device (not shown) in the hot water supply device control panel controls the temperature of the molten metal 5 measured by the thermocouple in the thermocouple protection tube 8 to be constant.

Further, the hot water supply pipe 4 has an inlet 41 for the molten metal soaked in the molten metal 5 held in the holding furnace 3, and the molten metal is placed at a position connected to the die casting machine plunger sleeve 33 and the lower receiving port 35. An electromagnetic sensor 30 having an outlet 42 and equipped with an electromagnetic sensor body 30a and an amplified pulse transmitter 30b mounted on the outer circumference of the hot water supply pipe 4 at a position as close as possible to the outlet 42 is mounted. ing.

The holding furnace 3 has an opening 27 for cleaning and inspecting the inside, receiving a molten metal from the outside, and a lid 28 for sealing the opening 27, and the opening 28 is opened if necessary. The work is performed using the part 27, and the holding furnace 3 is sealed during operation.

Further, the holding furnace 3 is connected to a pressure source 17 such as compressed air or an inert gas cylinder on a side wall or a ceiling portion at a position higher than the holding position when the maximum amount of the molten metal 5 is held, and opens and closes a pipeline in the middle. Has a pressurizing port 10 to which a pressurizing pipe 13 equipped with a pressurizing valve 15 is connected, and an exhaust valve 16 for opening and closing the pipeline in the middle of being opened to the external atmosphere for discharging the internal pressure. Exhaust port 11 connected to the equipped exhaust pipe 14
For measuring the pressure in the holding furnace 3 and bias control device 1
It has a pressure measuring port 9 connected to a pressure measuring tube 12 connected to the measuring port of the pressure transmitter 2 for transmitting the measured value.

The bias control device is installed in a hot water supply device control panel (not shown), and the electromagnetic sensor 30, the pressurizing valve 15, the exhaust valve 16, the pressure sensor 2, and the amplifier 51 are installed.
, And is electrically connected to the A / D converter 52.

The bias value of the initial data is input and set in the bias control device 1, the hot water supply timer value is input and set in the hot water supply timer in the hot water supply device control panel (not shown), and the hot water supply command is issued from the supplied device (not shown). When the hot water supply device control panel (not shown) receives it, the inside of the holding furnace 3 is pressurized by the pressure source 17
Pressurizing valve 15 for gas from, pressurizing port 10 via pressurizing pipe 13
Is pressurized by the inflow from.

When the inside of the holding furnace 3 is pressurized, the molten metal 5 flows into the hot water supply pipe 4 through the molten metal inlet 41, and the pressure inside the holding furnace 3 is the pressure measuring pipe connected to the pressure measuring port 9. It is measured at any time via the pressure sensor 2 via 12, amplified by the amplifier 51, converted as a digital signal by the A / D converter 52, and transmitted to the bias controller.

Thus, as described in the description (1) of the claims, the holding furnace 3 completes the absolute value control of the pressure increase amount after the metal melt is detected by the electromagnetic sensor 30, and the pressurizing pipe 13
The pressurizing valve 15 installed in the middle of the process stops the pressurization, and the exhaust valve 16 installed in the exhaust pipe 14 is opened and held after the hot water supply timer in the hot water supply device control panel not shown expires. The pressure in the furnace 3 returns to atmospheric pressure, and the hot water supply pipe 4
The ascending metal melt 5 inside returns to the holding furnace 3 from the metal melt inlet 41, and the supply of heat to the supply devices such as the die casting machine plunger sleeve 33 is completed.

Thus, as described in the description (1) regarding the claims, the hot water supply apparatus according to the claims uses the molten metal hot water supply method using the self-value remote bias control method, so that the hot water supply with high repeatability and less troubles occur. , Is realized as a device that realizes high-cycle hot water supply.

(4) FIG. 4 is a conceptual sectional view related to the claims.
In the figure, the heat insulation furnace 3 is a heating source such as a rod-shaped resistance heating element.
A temperature control device (not shown) in the hot water supply device control panel controls the temperature of the molten metal 5 measured by the thermocouple in the thermocouple protection tube 8 to be constant.

Further, the hot water supply pipe 4 has a metal molten metal inflow port 41 which is immersed in the metal molten metal 5 held in the holding furnace 3, and the metal is provided at a position in contact with the side hot water inlet 45 of the die casting machine plunger sleeve 33. An electromagnetic wave having an outlet 42 for the molten metal, which is attached to the outer circumference of the hot water supply pipe 4 at a position as close as possible to the outlet 42 (illustrated at a position separated for convenience). An electromagnetic sensor 30 including a sensor body 30a and an amplified pulse transmitter 30b is mounted.

The holding furnace 3 has an opening 27 for cleaning and inspecting the inside, receiving a molten metal from the outside, and a lid 28 for sealing the opening 27, and the opening 28 is opened if necessary. The work is performed using the part 27, and the holding furnace 3 is sealed during operation.

Further, the holding furnace 3 is connected to a pressure source 17 such as compressed air or an inert gas cylinder on a side wall or a ceiling portion at a position higher than the holding position when the maximum amount of the molten metal 5 is held, and opens and closes a pipeline in the middle. Equipped with a pressure port 10 to which a pressure pipe 13 equipped with a pressure valve 15 of is connected, and equipped with an exhaust valve 16 that is opened to the outside atmosphere to discharge the internal pressure and opens and closes the pipeline halfway Has an exhaust port 11 connected to an exhaust pipe 14 and connects to a pressure measuring pipe 12 connected to the measuring port of a pressure transmitter 2 for measuring the pressure in the holding furnace 3 and transmitting the measured value to the bias control device 1. The pressure measuring port 9 is provided.

The bias control device is installed in a hot water supply device control panel (not shown), and includes an electromagnetic sensor 30 and an exhaust valve 16
, The pressure valve 15, the pressure sensor 2, the amplifier 51, and the A / D converter 52 are electrically connected.

The bias value of the initial data is input and set in the bias control device 1, the hot water supply timer value is input and set in the hot water supply timer in the hot water supply device control panel (not shown), and the hot water supply command is issued from the supplied device (not shown). When the hot water supply device control panel (not shown) receives it, the inside of the holding furnace 3 is pressurized by the pressure source 17
Pressurizing valve 15 for gas from, pressurizing port 10 via pressurizing pipe 13
Is pressurized by the inflow from.

When the inside of the holding furnace 3 is pressurized, the molten metal 5 flows into the hot water supply pipe 4 through the molten metal inlet 41, and the pressure inside the holding furnace 3 is the pressure measuring pipe connected to the pressure measuring port 9. It is measured at any time via the pressure sensor 2 via 12, amplified by the amplifier 51, converted as a digital signal by the A / D converter 52, and transmitted to the bias controller.

Thus, as described in the description (1) of the claims, the holding furnace 3 completes the absolute value control of the pressure increase amount after the molten metal 5 is detected by the electromagnetic sensor 30,
Exhaust valve 16 installed in exhaust pipe 14 after the time of the hot water supply timer in the hot water supply device control panel (not shown) is closed by closing the pressurizing valve 15 installed in the middle of 13
Is released, the pressure in the holding furnace 3 is returned to atmospheric pressure, and the rising metal melt 5 in the hot water supply pipe 4 returns from the metal melt inlet 41 into the holding furnace 3 to prevent damage to the die casting machine plunger sleeve or the like. Hot water supply to the supply device is completed.

Thus, as described in the description (1) of the claims, the hot water supply apparatus according to the claims uses the molten metal hot water supply method using the bias control method, so that the hot water supply with high repeatability and less troubles can be performed in a high cycle. It is established as a device that realizes hot water supply.

As described above, various hot water supply devices utilizing the hot water supply method according to the claims are conceivable, but of course they can be applied as the hot water supply method in the holding hot water supply chamber of the melting and holding hot water furnace of the invention based on Patent Publication 64-6870.

In the claim, an electrode having a role as a positive electrode as a sensor for detecting molten metal and a conductive thermocouple protection tube having a role of a negative electrode are combined and configured. It is of course possible that the thermocouple protection tube does not have a negative pole role depending on the use.

In the claims and claims, an electromagnetic sensor is described as a sensor for detecting the molten metal, but this is not only an electromagnetic sensor but also a metal passage sensor or the like, which accurately detects the arrival of the molten metal from outside the hot water supply pipe. Any sensor that can be transmitted to the bias control device as an electric signal may be used.

Further, the shape of the holding furnace is sufficient as long as it can withstand pressurization in the furnace, can safely hold the molten metal, and can maintain a constant temperature. As long as the above can be maintained, various heating elements other than the rod-shaped heating element in the embodiment, a radiant tube type combustion heat source, a heating element type protected by a protective tube, and the like can be considered.

And the continuous hot water receiving device described in Patent Publication 64-6867,
Alternatively, it is naturally possible to apply the solid metal charging port described in Patent Publication 64-6868 to the hot water supply device according to the claims of the present invention.

Furthermore, in claim (1), the data stored in the data register is used as the control set value in the control value comparison operation unit by adding the preset bias value. However, the data stored in the data register itself It is, of course, possible to use as a control set value in the control value comparison calculation unit and to use a value obtained by subtracting a preset bias value from the measurement data transmitted as the comparison calculation measurement value.

[Effects of the Invention] As described above, according to the present invention, the materials separately submitted as physical properties are technical report materials centered on the current hot water supply accuracy based on Japanese Patent Laid-Open No. 487843, and are applications by the applicant of the present invention. It is the hot water supply accuracy verification data in the applicant's factory and the hot water supply accuracy verification data in the applicant's factory based on the present invention related to Japanese Patent Application No. Hei 1-90231. A molten metal hot water supply method and a hot water supply device that realize high-cycle hot water supply with less trouble are realized.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a flow diagram showing the concept of a molten metal hot water supply method using a bias control method according to the claims, FIG. 2 is a conceptual sectional view regarding the claims, and FIG. Is a conceptual cross-sectional view relating to the claims, FIG. 4 is a conceptual cross-sectional view relating to the claims, and FIG. FIG. 6 is a flowchart showing the above, and FIG.
FIG. 7 is a conceptual sectional view of the invention of FIG. 1, and FIG.
FIG. 8 is a conceptual sectional view relating to the invention of 843, and FIG.
It is a conceptual sectional view regarding the invention of -168546 and Japanese Patent Application No. 63-307126. 1 ... Bias control device, 2 ... Pressure sensor, 3 ... Holding furnace, 4 ... Hot water supply pipe, 5 ... Molten metal, 6 ... Hot water supply gutter,
7 ... Electrode, 8 ... Thermocouple protection tube, 9 ... Pressure measurement port,
10 ... Pressure port, 11 ... Exhaust port, 12 ... Pressure measuring tube, 13 ...
… Pressurizing pipe, 14 …… Exhaust pipe, 15 …… Pressurizing valve, 16 …… Exhaust valve, 17 …… Pressurizing source, 26 …… Heating source, 27 …… Opening part, 28 …… Lid, 30a …… Electromagnetic sensor main body, 30b …… Amplified pulse transmitter, 30 …… Electromagnetic sensor, 33 …… Die casting machine plunger sleeve, 35 …… Lower water inlet, 41 …… Inlet, 42 …… Outlet, 45 …… Side part Hot water inlet, 51 ... Amplifier,
52 ... A / D converter, the same reference numerals in the drawings indicate the same or corresponding parts.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Koichi Yoshioka, 1650 Aomi, Aomi, Aomi-cho, Nishikubiki-gun, Niigata Pref. Tanabe Kogyo Co., Ltd. Inspector Kato Tomoya (56) Reference JP-A-2-268957 (JP, A) JP-A-2-127955 (JP, A) JP 45-32351 (JP, B1) JP 63-61110 (JP, B2) JP 51-36704 (JP, B2)

Claims (4)

[Claims] 1. A hot water supply method for a pressurized hot water supply furnace, which is measured by a pressure sensor, amplified by an amplifier, and further A / D.
The pressure value in the pressurized hot water supply furnace converted into a digital signal value by the converter is input as an input value to the furnace pressure measurement value input section of the bias control device, and the pressure in the pressurized hot water supply furnace raises the inside of the hot water supply pipe. If the detection signal of the sensor installed at the fixed position of the incoming molten metal melt is not input, continue to take in the transmitted digital signal value, and if it is already input, the transmitted digital signal value is stored in the data storage judgment unit. The initial transmission data is stored in the data register and the preset bias value (variable setting deviation value)
And set as the control set value in the control value comparison calculation unit, and thereafter, the transmission data is sent to the control value comparison calculation unit,
It transmits as a measured comparison value, repeats the comparison calculation with the control set value, stops the pressurization into the pressurized hot water furnace at the same time as the control set value reaches the measured comparison value, and A method for supplying molten metal using a bias control method, which comprises quantitatively supplying hot water by exhausting the internal pressure of a pressurizing type hot water supply furnace after a preset time for a hot water supply timer has elapsed. 2. An apparatus for carrying out a molten metal hot water supply method using the bias control method according to claim 1, wherein the bias control apparatus and the bias control apparatus measure pressure as a digital signal value. A furnace pressure transmission device composed of a pressure sensor for transmission, an amplifier and an A / D converter; a molten metal held; and an inlet for the molten metal in the molten metal, which is supplied outside the furnace. The equipment is equipped with a hot water supply pipe having an outlet for the molten metal in contact with a hot water supply gutter for supplying the molten metal to the equipment, and is equipped with a heat source for keeping the temperature of the retained molten metal constant, A thermocouple protection tube, which has a thermocouple for measuring the temperature of the molten metal and has the function of an electrode serving as a negative electrode, is installed inside the molten metal outlet of the hot water supply pipe. Inside the hot water supply pipe, which is placed opposite to the negative electrode of the An electrode as a positive electrode for detecting the rising metal melt at a fixed point is attached, and it is connected to a pressure source such as compressed air or an inert gas cylinder to pressurize the inside and opens and closes the pipeline in the middle. It has a pressurizing port connected to a pressurizing pipe equipped with a pressurizing valve, and has an exhaust port connected to an exhaust pipe equipped with an exhaust valve for opening and closing a pipeline on the way to the outside, Equipped with a pressure measurement port connected to the pressure measurement pipe connected to the measurement port of the furnace pressure transmission device, the opening and the above-mentioned opening for cleaning and inspecting the inside and receiving molten metal from the outside A hot water supply device comprising: a holding furnace having a lid for hermetically sealing a portion. 3. An apparatus for carrying out a molten metal hot water supply method using the bias control method according to claim 1, wherein the bias control apparatus and the bias control apparatus measure the pressure as a digital signal value. A furnace pressure transmission device composed of a pressure sensor for transmission, an amplifier and an A / D converter, and a molten metal which holds the molten metal and has an inflow port for the molten metal inside the molten metal outside. The die casting machine which is the supply device is connected to the lower inlet of the plunger sleeve, and is equipped with a hot water supply pipe having an outlet for molten metal, and is equipped with a heat source for keeping the temperature of the molten metal constant, An electromagnetic sensor equipped with a thermocouple protection tube containing a thermocouple for measuring the temperature of the molten metal, and detecting the passage of the internal molten metal outside the molten metal pipe near the metal molten metal outlet of the molten metal pipe. Mount the sensor and It has a pressure port that is connected to a pressure source such as compressed air or an inert gas cylinder for pressurizing and is equipped with a pressure valve for opening and closing the pipeline on the way, and is open to the outside It has an exhaust port connected to the exhaust pipe equipped with an exhaust valve for opening and closing the pipeline, and equipped with a pressure measurement port connected to the pressure measurement pipe connected to the measurement port of the furnace pressure transmitter. A water heater comprising an opening for cleaning or inspecting the inside and receiving a molten metal from the outside, and a holding furnace having a lid for sealing the opening. . 4. An apparatus for carrying out a molten metal hot water supply method using the bias control method according to claim 1, wherein the bias control apparatus and the bias control apparatus measure the pressure as a digital signal value. A furnace pressure transmission device composed of a pressure sensor for transmission, an amplifier and an A / D converter, and a molten metal which holds the molten metal and has an inflow port for the molten metal inside the molten metal outside. A hot water supply pipe having an outlet for molten metal in contact with a plunger sleeve side portion receiving port of a die casting machine which is a supply device is attached, and a heat source for keeping the temperature of the molten metal constant is attached, An electromagnetic sensor equipped with a thermocouple protection tube containing a thermocouple for measuring the temperature of the molten metal, and detecting the passage of the internal molten metal outside the molten metal pipe near the metal molten metal outlet of the molten metal pipe. Mount the sensor and add It has a pressurizing port connected to a pressurizing source such as compressed air or an inert gas cylinder, which is equipped with a pressurizing valve to open and close the pipeline in the middle, and is open to the outside It has an exhaust port connected to the exhaust pipe equipped with an exhaust valve for opening and closing the pipeline, and equipped with a pressure measurement port connected to the pressure measurement pipe connected to the measurement port of the furnace pressure transmitter. A water heater comprising an opening for cleaning or inspecting the inside and receiving a molten metal from the outside, and a holding furnace having a lid for sealing the opening. .