JPS6361110B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is directed to pressurizing the molten metal in a heat-retaining furnace in which molten metal is stored, and to pressurizing the molten metal in the heat-retaining furnace and using an electromagnetic device installed outside a transport pipe connected to the heat-retaining furnace. This invention relates to a molten metal water supply device that supplies hot water by using a pump in combination.

[Prior Art and its Problems] Conventionally, various devices have been known for supplying molten metal to a mold or a plunger sleeve of a die-casting machine.

Among these, the water heater shown in FIG.
In this device, a heating element 14 is provided, and molten metal 2 is pumped up from a pumping port 30 using an automatically mechanized ladle 31 to supply the hot water to, for example, a plunger sleeve 7 of a die-casting machine. This main water heater is Mg
It is applied to general molten metals excluding chemically unstable molten metals such as molten metals.

However, the hot water supply apparatus using the ladle has a problem in that the surface of the molten metal 2 in the insulating furnace 1 is constantly stirred, and miscellaneous foreign substances such as oxides floating on the surface are supplied together with the molten metal.

Further, the hot water supply apparatus shown in FIG. 3 includes a hot water supply pipe 3 provided in a sealed heat retention furnace 1 for storing molten metal 2, and a heating element 14 disposed in the upper part of the heat retention furnace 1. This device is equipped with an automatic metering device 35 for supplying the molten metal 2, and further has an electrode 32 arranged at the molten metal outlet 33 of the hot water supply pipe 3 to detect the molten metal 2. Then, the molten metal flowing out from the hot water supply pipe 3 is supplied to the plunger sleeve 7 of the die casting machine using the gutter 34.

However, in the water heater using the automatic metering device 35 described above, clean molten metal is supplied from the lower part of the heat retention furnace 1 and has an excellent temperature, but it is once released to the outside at the outlet of the hot water supply pipe 3 and then sent to the gutter 34. In order to flush, the said gutter 3
4 or when flowing into the plunger sleeve 7, there were problems such as generation of oxides and increased entrainment and absorption of gas components. Furthermore, the hot water supply apparatus shown in FIG.
4, a hot water supply pipe 3 for supplying molten metal to the outside from the lower side is provided, and an electromagnetic pump 25 is installed on the outside of the hot water supply pipe 3. The molten metal flowing through the hot water supply pipe 3 by the electromagnetic pump 8 is supplied to the plunger sleeve 7 of the die casting machine from the lower side. This type of water heater is used to supply hot water to chemically unstable molten metals such as Mg, and in the case of plunger sleeve 7, etc., it can supply hot water quietly from the lower side, so the contact surface with the outside air is limited. It is suitable for generating oxides, entraining and absorbing gas components, etc., and does not cause turbulence.

However, the hot water supply device using the electromagnetic pump 8 has a long horizontal part of the hot water supply pipe 3 due to its structure, and the electromagnetic pump 8 part must always be supplied with molten metal. tube 3
There is a high risk of solidification within the furnace, and there is also a risk of problems such as a high risk of breakage at the connection between the heat insulating furnace 1 and the hot water supply pipes 3, and at the connection between the hot water supply pipes 3. Although it is possible to avoid constantly supplying molten metal to the electromagnetic pump 8 section by tilting it when not supplying water, this is not practical when considering the system configuration of the heat retention furnace 1 and the casting machine (die casting machine). . Furthermore, when the above-mentioned problems occur, maintainability may be poor and the cost may be high.

Further, the hot water supply apparatus shown in FIG. 5 is provided with a hot water supply pipe 3 in a sealed heat retention furnace 1 for storing molten metal 2, and an automatic metering device 35 for supplying the molten metal 2 in the heat retention furnace 1. and hot water pipe 3
This device is equipped with an electromagnetic sensor 9 that detects the passage of molten metal. The molten metal that has risen through the hot water supply pipe 3 under pressure control by the automatic metering device 35 is supplied to the plunger sleeve 7 of the die casting machine from the lower side. The hot water supplied by this device is clean and temperature-controlled, with no foreign matter mixed in, and the molten metal is heated while minimizing the generation of oxides, entrainment, and absorption of gas components, and is suitable for maintenance. It is something.

However, it is said that the current state of the art in the method of controlling the pressurization inside the heat retention furnace using the electromagnetic sensor described above is that the detection accuracy of the electromagnetic sensor for passing the molten metal is ±10 mm at the set position. Therefore, this electromagnetic sensor detection accuracy poses a problem in securing a value of ±2%, which is generally required as hot water supply accuracy.

[Object of the invention] The present invention has been made in view of the above circumstances, and
It enables the production of high-quality castings by supplying molten metal that is clean and temperature-controlled without contamination by foreign objects, minimizing the entrainment and absorption of gas components during the process, and supplying the molten metal with accurate quantity. The purpose of the present invention is to provide a molten metal water heater.

[Means for Solving the Problems] Examples of the present invention will be described below with reference to the drawings.

FIG. 1 is a diagram showing the structure of a molten metal hot water supply apparatus according to an embodiment of the present invention. In the figure, a heat retention furnace 1 of a water heater is made of a material having fire resistance and heat insulation properties, and is formed into a substantially box shape as a tank for storing molten metal 2 therein. A molten metal receiving port 16 is formed on one side of the heat-retaining furnace 1.
A lid 15 is provided to cover and seal the molten metal receiving port 16. A resistance-type heating element 14 made of rod-shaped silicon carbide or nichrome wire is provided in the upper part of the heat-retaining furnace 1, and this heating element 14 is connected to a power source via a power regulator 13 such as a thyristor type. ing. Further, the heat retention furnace 1 is provided with a molten metal temperature measuring body 11 whose detection end is disposed in the molten metal 2 of the heat retention furnace 1, diagonally penetrating the horizontal side wall on the side of the molten metal receiving port 16. There is. The molten metal temperature measuring body is connected to the power regulator 13, such as the thyristor type, via a temperature controller 12. That is, the molten metal temperature sensor 11 detects the temperature of the molten metal 2, compares it with the temperature set by the temperature controller 12, and adjusts the heating element using a power regulator 13 such as a thyristor type based on the comparison temperature. Temperature control is performed by controlling the amount of heat to 14 (for example, on/off control). A pressurizing port 24 for introducing gas into the upper part of the heat-retaining furnace 1 to pressurize the inside of the heat-retaining furnace 1;
An exhaust port 25 is provided to exhaust gas and release pressure. The pressurizing port 24 is piped externally and is connected to the pressurizing source 17 with a pressurizing valve 18 interposed therebetween. This pressurization source 18 is, for example, a device capable of supplying pressurized gas such as air compressed by a compressor or an inert gas cylinder.
The pressurizing valve 18 is a solenoid valve or the like that opens and closes based on a predetermined control signal from a pressurizing control device 26, which will be described later. Further, the exhaust port 25 is externally connected to the exhaust valve 19 via piping, and is opened to the atmosphere. The exhaust valve 19 opens and closes based on a predetermined control signal from the pressurization control device 26.
Such as a solenoid valve.

Furnace pressure measuring ports 22 and 23 are provided in the upper part of the heat-retaining furnace 1 to measure its internal pressure.
Of these, the furnace pressure measurement port 23 is connected to a pressure indicator 20 via piping on the outside and always indicates the pressure inside the furnace. Further, the furnace pressure measurement port 22 is connected to a pressure alarm gauge 21 via piping on the outside. This pressure alarm gauge 21 is activated if the pressure inside the heat retention furnace 1 does not reach a set pressure within a certain period of time after the pressure inside the heat retention furnace 1 is pressurized by a pressure control device 26 (described later), or conversely, if the pressure in the heat retention furnace 1 exceeds a separately set pressure. 1, it is determined that an abnormality has occurred and pressurization is stopped, the exhaust valve 19 is opened, and hot water supply is stopped.

Further, the heat-retaining furnace 1 is provided with a hot water supply pipe 3 made of a heat-resistant material. This hot water pipe 3
is opened at one end as the molten metal inlet 4 at the bottom side of the heat retention furnace 1, and the other end is opened as the molten metal inlet 4 at the bottom side of the heat retention furnace 1.
It penetrates from the top and is connected to the transport pipe 5 on the outside. An electromagnetic pump 8 is provided outside the transport pipe 5.
is provided.

This electromagnetic pump 8 follows Fleming's law,
A pump that can obtain driving force by applying an electric current and a magnetic field to molten metal. That is, three-phase alternating current is supplied to the coil to generate a moving magnetic field in the molten metal, and the molten metal is continuously driven by the induced current generated in the molten metal and the moving magnetic field. The flow rate can be changed by changing the voltage with a voltage regulator,
The driving direction can also be reversed by switching the current phase.

The other end of the portion of the transport pipe 5 connected to the hot water supply pipe 3 is connected to a sleeve connecting pipe 6. An electromagnetic sensor 9 is provided outside the sleeve connecting pipe 6 on the transport pipe 5 side to detect the arrival of molten metal. This electromagnetic sensor 9 is composed of an electromagnetic sensor main body 9a provided outside the sleeve connecting pipe 6 and an amplified pulse transmitter 9b, and this amplified pulse transmitter 9b controls the arrival of molten metal to the pressure control device 26. transmit signals. The electromagnetic sensor 9 applies the principle of an electromagnetic flowmeter. In other words, when a conductive liquid flows through a tube placed in a magnetic field, a conductive liquid flows between a pair of electrodes facing the tube wall perpendicular to the direction of the flow and the magnetic field, according to Faraday's law. An electromotive force is generated based on the potential gradient generated. By detecting this electromotive force, arrival of the molten metal can be detected.

The sleeve connecting pipe 6 communicates with the lower side of the plunger sleeve 7 of the die-casting machine, which is the supplied side.

Further, the pressurizing valve 18, the exhaust valve 19, the pressure alarm meter 21, and the electromagnetic sensor 9 are connected to a pressurizing control device 26 so that predetermined control, which will be explained later, is performed. Similarly, the electromagnetic pump 8 is connected to the central control device 27, and is operated and stopped based on signals sent from the pressurization control device 26 to the central control device.

Next, the operation of the water heater having the above configuration will be explained. First, the amount of molten metal 2 required for hot water supply is poured into the molten metal receiving port 16, the lid 15 is closed, and the insulating furnace 1 is heated.
Seal it tightly. Next, after setting the temperature controller 12 to a temperature necessary for keeping warm, power is supplied to the heating element 14 by a power regulator 13 such as a thyristor type, and the temperature of the molten metal is controlled. When a hot water supply request signal from a casting machine such as a die-casting machine, which is the supplied side, reaches the pressurization control device 26 via the central control device 27, the pressurization valve 18 opens and at the same time, the exhaust valve 19 closes. As a result, gas is introduced from the pressure source 17, the pressure inside the heat retention furnace 1 increases, and the pressure at that time is transmitted to the pressure indicator 20 and the pressure alarm indicator 21.
Therefore, the molten metal 2 ascends from the heat retention furnace 1 through the hot water supply pipe 3, passes through the transport pipe 5, and reaches the electromagnetic sensor detection position 10 where the electromagnetic sensor main body 9a is attached to the outside of the sleeve connecting pipe 6. The arrival of the molten metal is amplified as a pulse by the pulse generator 9b.
The pressure is transmitted to the pressurization control device 26 from there. At this moment, the pressurizing valve 18 is closed and an operating signal is sent to the electromagnetic pump 8 via the central control device 27.

Up to this point, the pressure at the time when the built-in timer of the pressurization control device 26 has elapsed is the pressurization alarm meter 2.
If the pressure set to 1 is not reached, it is assumed that an abnormality has occurred, and the pressurizing valve 18 is closed and the exhaust valve 19 is opened. At the same time, if the pressure inside the heat-retaining furnace 1 reaches a level higher than the pressure set on the pressure alarm meter 21, it is assumed that an abnormality has occurred, and the pressure valve 18 is closed and the exhaust valve 19 is opened.

When the electromagnetic pump 8 is operated, the molten metal further rises within the sleeve connecting pipe 6 and reaches the shot sleeve 7 of the die casting machine. The electromagnetic pump 8 is operated until the time period for supplying the required amount of hot water to the shot sleeve 7 at the voltage set by the central controller 27 has elapsed. When the predetermined time is reached, the central controller 27 issues a stop signal to the electromagnetic pump 8, and the electromagnetic pump 8 is stopped.

As a result, an accurately measured amount of molten metal is supplied from the sleeve connection port 6 to the plunger sleeve 7 of the die-casting machine. At this time, since the plunger sleeve 7 is supplied from the lower side, the generation of oxides, the entrainment and absorption of gas components, etc. are reduced.

Then, at the same time that the injection plunger of the die-casting machine passes through the connection port between the plunger sleeve 7 and the sleeve connection pipe 6, the exhaust valve 19 opens to release the pressure inside the heat retention furnace 1 to the outside of the furnace, and the electromagnetic pump 8 The rotation is reversed for about 1 second, and the molten metal in the sleeve connection port 6, the transport pipe 5, and the hot water supply pipe 3 returns to the heat-retaining furnace and ends.

Furthermore, since the detection of the molten metal in the sleeve connecting pipe 6 is performed by the magnetic sensor 9, it is not affected by the metal thin film generated inside the sleeve connecting pipe 6, and the probability of erroneous confirmation of arrival of the molten metal is reduced. .

In the above embodiment, the electromagnetic sensor 9 may be of any type as long as it can detect the arrival of the molten metal 2.
Further, it is sufficient that the molten metal inlet 4 of the hot water supply pipe 3 is arranged in the bottom middle layer of the heat retention furnace 1 which is sufficiently lower than the molten metal level, and that it is connected to the transport pipe 5 outside the heat retention furnace 1 at a position higher than the molten metal level. .

The transport pipe 5 only needs to be arranged substantially horizontally and have a length necessary for attaching and maintaining the electromagnetic pump 8.

Further, it is preferable that the molten metal 2 is supplied from the lower side, and the present invention is applicable to areas other than the plunger sleeve 7.

Note that the heat retention furnace 1 may be a closed furnace in which the temperature of the molten metal 2 is controlled, and its shape, structure, etc. are not limited to those of the embodiment.

[Effects of the Invention] As explained above, according to the present invention, in a sealed holding furnace, a clean molten metal that is free from foreign matter and whose temperature is well controlled is processed by the generation of oxides and the like. It reduces entrainment and absorption of gas components, enables hot water to be supplied with high quantitative accuracy, and enables the production of high-quality castings.

[Brief explanation of drawings]

Fig. 1 is a diagram showing the structure of a molten metal water heater according to an embodiment of the present invention, Fig. 2 is a diagram showing the structure of a conventional water heater using a ladle, and Fig. 3 is a pressurized automatic water heater. Figure 4 is a diagram showing the structure of a conventional water heater that supplies hot water from the top of the shot sleeve of a die-casting machine using a metering device; Figure 4 is a diagram showing the structure of a conventional water heater that uses an electromagnetic pump; The figure shows the structure of a conventional hot water supply device that uses a pressurized automatic metering device using an electromagnetic sensor and supplies hot water from the lower part of the shot sleeve of a die-casting machine. DESCRIPTION OF SYMBOLS 1... Heat retention furnace, 2... Molten metal, 3... Molten metal supply pipe, 4... Molten metal inlet, 5... Transport pipe, 6... Sleeve connection pipe, 7... Die casting machine shot sleeve, 8... Electromagnetic pump, 9... Electromagnetic sensor, 9a... Electromagnetic sensor body, 9b... Amplified pulse transmitter, 10... Electromagnetic sensor detection position, 11...
...Molten metal temperature measuring element, 12...Temperature controller, 13...
...Thyristor type power regulator, etc., 14...Heating element, 15...Lid, 16...Molten metal receiving port, 17...
Pressure source, 18... Pressure valve, 19... Exhaust valve, 20
...Pressure indicator, 21...Pressure alarm meter, 22,2
3... Furnace pressure measuring port, 24... Pressurizing port, 25... Exhaust port, 26... Pressurizing control device, 27... Central control device, 30... Molten metal pumping port, 31... Ladle, 32... ...electrode, 33...molten metal outlet, 34...
...Gutter, 35... Automatic weighing device. Note that the same reference numerals in the figures indicate the same or corresponding parts.

Claims (1)

[Claims] 1. A closed heat-retaining furnace that stores molten metal, a heating element installed in the heat-retaining furnace, a temperature measuring element that detects the temperature of the molten metal, and a temperature controller that detects the temperature of the heating element based on this detection signal. a power regulator for controlling the calorific value; a hot water supply pipe for supplying the molten metal having a molten metal inlet in the molten metal of the heat retention furnace and connected to a transport pipe outside the furnace; It is equipped with an electromagnetic pump and has a transport pipe connected to a sleeve connecting pipe, and has a sleeve connecting pipe connected to the transport pipe and connected to a die casting machine plunger sleeve, and prevents the molten metal from reaching the sleeve connecting pipe from the outside. It has an electromagnetic sensor that detects the temperature inside the furnace, and a pressurization valve that controls the supply of gas from a pressurization source such as compressed air or an inert gas cylinder via piping to the pressurization port that pressurizes the inside of the heating furnace. , has an exhaust valve installed at the exhaust port to discharge the pressure inside the heating furnace to the outside, and has a pressure gauge to indicate the pressure inside the heating furnace. A pressurization control device has a pressure alarm gauge to issue an alarm and stop pressurizing the inside of the heating furnace when and a central control device for operating and stopping the electromagnetic pump and controlling the supply of molten metal to the plunger sleeve of the die casting machine based on signals from the pressurization control device. Molten metal water heater.