JPS646868B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is for an automatic molten metal measuring device that pressurizes the inside of a heat retention furnace in which molten metal is stored, automatically measures the molten metal, and supplies hot water to the outside of the heat retention furnace. This relates to a solid metal inlet.

[Prior art and its problems] Conventionally, as an automatic metering device for quantitatively supplying molten metal, for example, as shown in FIG. In addition to providing a hot water supply pipe 3, the molten metal 1 in the heat retention furnace 2
There is an apparatus that includes a pressurization control section 4 for supplying molten metal and a hot water supply sensor 6 that detects molten metal 1 at a molten metal outlet 5 of a hot water supply pipe 3. Then, the molten metal flowing out from the hot water supply pipe 3 is supplied to the plunger sleeve 8 and the like of the die casting machine using the gutter 7.

However, in the automatic molten metal measuring device mentioned above,
Normal molten metal is supplied from the lower part of the insulating furnace, which is superior in terms of temperature, but if the amount of molten metal held in the insulating furnace that can be supplied is exceeded and new molten metal is received after being supplied outside the furnace, casting work is required. However, the amount required for one shift in the casting process is only slightly insufficient, and if possible, the capacity of the insulating furnace is sufficient to melt the shortage in cases such as when melting solid metal. Despite having extra capacity, there was still a problem in that casting operations had to be suspended in order to accept solid metal.

[Object of the invention] The present invention has been made in view of the above circumstances, and
Automatic measurement of molten metal that allows solid metal to be received and melted without interrupting casting operations or causing sudden changes in molten metal temperature to correct the slight shortage of molten metal during one shift in the casting process. The purpose is to provide a solid metal inlet for equipment.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a heating element provided in a closed heat-retaining furnace for storing molten metal, and a temperature measuring element to measure the temperature of the molten metal. A power regulator is provided to control the calorific value of the heating element using a temperature controller based on this detection signal, and the molten metal has a molten metal inlet inside the molten metal and an outlet outside the furnace. A sensor for detecting the arrival of molten metal is provided at the outlet of the hot water supply pipe for supplying the hot water, and a pressurization control unit is provided for pressurizing the gas introduced into the heat retention furnace in accordance with a signal from this sensor. An automatic measuring device for molten metal, which is equipped with a cleaning port and molten metal receiving port for periodically discharging a small amount of slag generated inside the device, and a lid for sealing the cleaning port and molten metal receiving port. In one shift of casting operations, there is a slight shortage (for example, 10% of the holding furnace storage capacity).
~15%) To replenish the amount of molten metal, there is a solid metal receiving port outside the furnace, and a mechanical pressure welding mechanism (pneumatic cylinder, hydraulic cylinder, motor-driven cam, etc.);
By providing a solid metal input port with a solid metal discharge port in the furnace, we have demonstrated that solid metal can be melted in small amounts at regular intervals without interrupting the casting operation or causing sudden temperature changes. Features.

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

FIG. 1 is a diagram showing the structure of an automatic molten metal measuring device according to an embodiment of the present invention. In the figure, a heat retention furnace 2 having a hot water supply device is made of a furnace material 10 having fire resistance and heat insulation properties, and is formed into a substantially box shape as a tank for storing molten metal 1 inside. A solid metal inlet 27 is provided on the ceiling of the insulating furnace, which is relatively close to the side.
It has a lid 28 with a mechanical pressure welding device (the example shown is a pneumatic cylinder, other examples are omitted) 29 for sealing the furnace when solid metal is not received and not impairing the airtightness of the insulating furnace. There is. Further, on one side of the heat retention furnace, there is a cleaning port and molten metal receiving port for periodically discharging some slag, etc., generated as the solid metal is melted from the solid metal input port 27. 12 and a lid 13 for sealing the cleaning port/molten metal receiving port 12. A resistance type heating element 11 (shown is a rod-shaped silicon carbide heating element) having a rod-shaped silicon carbide or nichrome wire arranged on the upper part of the heat-retaining furnace 2 is provided.
It is connected to a power supply via a thyristor power regulator 19. Further, the heat-retaining furnace 2 is provided with a molten metal temperature measuring body 21 which diagonally penetrates the lateral side on the side of the cleaning port 12 and has a detection end disposed within the molten metal 1 of the heat-retaining furnace 2. It is being The molten metal temperature measuring body 21 is connected to the thyristor type power regulator via the temperature controller 20. That is, the molten metal temperature sensor 21 detects the temperature of the molten metal 1, compares it with the temperature set by the temperature controller 20, and controls the thyristor type power regulator 19 to control the temperature of the heating element 11 based on the comparison temperature. Control the amount of heat (e.g.
Temperature control is performed by PID control). Gas is introduced into the upper part of the heat retention furnace, and this heat retention furnace 2
A pressurizing port 35 for pressurizing the inside and an exhaust port 36 for discharging gas to release the pressure are provided. The pressurizing port 35 is piped externally, and there is a pressurizing valve 1 in the middle.
The pressure source 15 is connected to the pressure source 15 via the pressure source 15 . This pressurization source 15 is, for example, a device capable of supplying pressurized gas such as air compressed by a compressor or inert gas filled in a cylinder. The pressurizing valve 16 opens and closes based on a predetermined control signal from a pressurizing control device 34, which will be described later. Such as a solenoid valve. Further, the exhaust port 36 is connected to the exhaust valve 17 via piping on the outside and is opened to the atmosphere. The exhaust valve 17 is a solenoid valve or the like that opens and closes based on a predetermined control signal from a pressurization control device 34, which will be described later.

An in-furnace pressure measuring port 14 is provided at the upper part of the heat-retaining furnace 2 to measure its internal pressure. This in-furnace pressure measurement port 14 is externally connected to a differential pressure transmitter 31 and a pressure regulator 30 via piping. This differential pressure transmitter 31 has two measurement chambers 31a and 31a.
It has a measurement chamber 31b, one measurement chamber 31b is connected to the measurement port 14 by interposing a solenoid valve 32 in the middle of the piping, and there are two measurement chambers 31a and 31b.
The difference in pressure applied to the two is detected. The differential pressure transmitter 31 is connected to a differential pressure regulator 33,
Both constitute a differential pressure detection section. Further, the furnace pressure measurement port 14 is connected to a pressure regulator 30. The differential pressure regulator 33, the pressure regulator 30, the pressurizing valve 16, the exhaust valve 17, and the solenoid valve 32
and are connected to a pressurization control device 34 so that predetermined control, which will be described later, is carried out. As mentioned above, the pressurization control section 4 includes the solenoid valve 32 and the differential pressure transmitter 3.
1, a differential pressure regulator 33, a pressure regulator 30, and a pressurization control device 34.

Further, the heat-retaining furnace 2 is provided with a hot water supply pipe 3 made of a heat-resistant material. This hot water pipe 3 is
One end thereof is opened as the molten metal inlet 9 at the bottom side of the heat retention furnace 2, and the other end is the molten metal outlet 5.
It is opened to the outside. This molten metal outlet 5
The hot water sensor 6 is configured with one of electrode type, photoelectric type, sonic type, electromagnetic type, etc. (electrode type is shown).
is provided. The hot water sensor 6 detects the passage of molten metal and transmits the detection to the pressurization control device 34 . The molten metal outlet 5 is communicated via a gutter 7 to a side to be supplied such as a plunger of a die-casting machine.

Next, the operation of the automatic weighing device having the above configuration will be explained. First, the molten metal 1 up to the holding limit required for hot water supply is received from the cleaning port/molten metal receiving port 12, and then the cleaning port/molten metal receiving port 12
The lid 13 is closed to seal. Then,
After setting the temperature controller 20 to a temperature necessary for heat retention, power is supplied to the heating element 11 by the thyristor type power regulator 19, and the temperature of the molten metal is controlled.
The pressurization control section 4 can be operated by operating a key switch (not shown). In response to a hot water supply request signal from a casting machine (such as a die casting machine), the exhaust valve 17 is closed and the pressurizing valve 16 is opened under the control of the pressurizing control device 34. As a result, the pressure source 15
From there, compressed air or gas such as inert gas flows into the heat retention furnace 2, and the internal pressure increases. Due to this increase in internal pressure, the molten metal in the heat insulating furnace 2 flows into the hot water supply pipe 3 from the molten metal inlet 9, flows out from the molten metal outlet 5, and is supplied to the die casting machine plunger sleeve or the like via the trough 7. At this time, the solenoid valve 32 is closed at the timing when the hot water supply sensor 6 detects molten metal. As a result, the pressure inside the heat retention furnace 2 at the moment when the molten metal flows out from the outlet 5 is set in the measurement chamber 31b within the differential pressure transmitter 31.

Here, the pressure control device 34 (programmable controller or sequencer) measures the pressure inside the holding furnace at this point from the furnace pressure measurement port 14 through the pressure regulator 30, and automatically controls the pressure of each molten metal in advance. Verify the metering device, and if it corresponds to the specified value, continue pressurizing. Also,
If it is out of range, pressurization is stopped.

If the pressurization continues, the molten metal naturally continues to rise inside the hot water supply pipe 3 and is supplied to the outside.

Thereafter, the pressure inside the heat-retaining furnace 2 is determined by continuously measuring the pressure at the time of detection of the hot water sensor 6 and the amount of pressure increase thereafter via a differential pressure detecting section consisting of a differential pressure transmitter 31, a differential pressure regulator 33, etc. By measuring the absolute pressure increase amount more quantitatively and safely, the individual molten metal automatic measuring devices are individually verified in the same way as the safe limit pressure mentioned above, and the Based on the hot water supply amount per unit time-pressure relationship graph, the pressurization control device 34 controls the differential pressure controller 3.
3, the pressurization is stopped by closing the pressure valve 16.

Here, the detection position of the hot water supply sensor 6 is the holding furnace 2.
Regardless of the shape change (including the accumulation of slag etc. on the hearth or adhesion to the sides),
This becomes a fixed point in hot water supply, and the pressure increase amount set in the differential pressure regulator 33 becomes important as an absolute value control element in quantitatively supplying hot water for a certain period of time.

In this way, if the hot water supply is continued based on the hot water supply request signal from the casting machine, the amount of molten metal in the heat insulating furnace 2 will eventually decrease and it will be necessary to replenish the molten metal. In order to replenish this small amount of molten metal, a small amount of return material (runners, etc.) from which the product has been removed from the casting is melted in the heat retention furnace 2 using the surplus heat supply capacity that does not affect the temperature control of the molten metal. Here, the lid 28 of the solid metal inlet 27 of the present invention is connected using the mechanical pressure welding mechanism 29 during the off cycle of the hot water supply operation and the hot water supply operation (in one embodiment, when the inside of the heat retention furnace 2 is not pressurized). The off-cycle time is 25 seconds for the pressurization time in the heat retention furnace 2, which is 7 seconds.
A solid metal charging device (not shown) or the like is used to charge the solid metal, and a small amount of the solid metal is melted without interrupting the casting operation. When charging of the solid metal is completed, the lid 28 is immediately closed using the mechanical pressure welding mechanism 29, and the inside of the heat-retaining furnace 2 is sealed again, and the furnace is in a standby state for a hot water supply request signal from the casting machine.

In this case, if the casting is quickly separated into the product and the return material and fed into the solid metal receiving port 27, the solid metal can be fed into the solid metal receiving port 27 while being kept at a temperature of 150°C to 250°C. This makes it possible to expect an extremely large thermal energy effect.

In addition, in the above embodiment, the solid metal inlet 2
7, the solid metal reception port 37 is arranged above the upper casing of the heat retention furnace 2, and the solid metal discharge port 38 is arranged above the top surface of the molten metal when the molten metal is held at maximum in the heat retention furnace 2. .

Furthermore, as shown in FIG.
The solid metal receiving port 37 is arranged outside the side casing of the heat insulating furnace 2, penetrates the side wall of the heat insulating furnace 2, and the solid metal discharge port 38 is arranged on the top surface of the molten metal in the heat insulating furnace 2 when the molten metal is held at maximum. It only needs to be placed higher.

The present invention is not limited to an automatic molten metal measuring device, but also a pressurized distribution device, which is a device for distributing molten metal from a closed melting furnace to the outside of the melting furnace by pressurizing the inside of the melting furnace using gas. It can also be carried out in a melting furnace with a hot water device.

[Effects of the Invention] As explained above, according to the present invention, the slight shortage of molten metal during one shift in the casting process can be corrected without interrupting the casting operation, and the temperature of the molten metal can be rapidly increased. without causing major changes,
A solid metal inlet for an automatic molten metal metering device has become available, which allows the reception and melting of some solid metal (such as small ingots or return materials separated from cast products).

[Brief explanation of drawings]

FIG. 1 is a diagram showing the structure of an automatic molten metal measuring device according to an embodiment of the present invention provided with a solid metal inlet, FIG. 2 is a diagram showing the structure of a conventional automatic molten metal measuring device, FIG. 3 is a graph showing the relationship between the amount of hot water supplied per unit time and pressure, which is individually verified. 1... Molten metal (molten metal), 2... Heat retention furnace, 3...
... Hot water supply pipe, 4 ... Pressure control section, 5 ... (Hot water pipe)
Molten metal outlet, 6... Hot water supply sensor, 7... Gutter, 8...
...Die-casting machine plunger sleeve, 9...
(Hot water supply pipe) Molten metal inlet, 10... Heat retention furnace furnace material, 1
1... Heating element, 12... Cleaning port and molten metal receiving port, 13... (Cleaning port and molten metal receiving port) lid, 1
4...Furnace pressure measurement port, 15...Pressure source, 16...
...Pressure valve, 17...Exhaust valve, 18...Electric wire, 19
... Thyristor type power regulator, 20 ... Temperature controller, 21 ... Molten metal temperature sensor, 27 ... Solid metal inlet, 28 ... (solid metal inlet) lid, 29...
...(Solid metal input port cover) Mechanical pressure welding mechanism, 30...
...Pressure regulator, 31...Differential pressure transmitter, 32...Solenoid valve, 33...Differential pressure regulator, 34...Pressure control device (programmable controller or sequencer), 35...Pressure port, 36... ...Exhaust port, 37...
...Solid metal intake port, 38...Solid metal discharge port.

Claims (1)

[Claims] 1 a sealed heat-retaining furnace 2 for storing molten metal 1;
The temperature of the heating element 11 provided in the heat insulating furnace 2 and the temperature of the molten metal 1 is detected by the temperature measuring element 21, and based on this detection signal, the temperature controller 20 detects the temperature of the heating element 11 and the molten metal 1.
1; a power regulator 19 for controlling the calorific value of molten metal 1; , a sensor 6 that detects the molten metal rising inside the hot water supply pipe 3 at a fixed point, and a pressurization control section 4 that pressurizes and controls the gas introduced into the heat retention furnace 2 in accordance with the signal from the sensor 6. and a heating furnace 2 from a hot water supply pipe 3 by the measuring device.
During measurement to supply a fixed amount of molten metal to the outside, solid metal is continuously received from outside the heat insulating furnace 2 without interrupting the measurement operation and without impairing the effectiveness of measurement accuracy. A mechanical pressure welding mechanism 29 (pneumatic cylinder,
A solid metal inlet 27 having a lid 28 with a hydraulic cylinder, a motor-driven cam, etc.) and a solid metal outlet 38 in the furnace, and melting of the solid metal received from the solid metal inlet 27. A cleaning port and molten metal receiving port 12 for periodically discharging some slag, etc. generated due to the process, and a lid 1 for sealing the cleaning port and molten metal receiving port 12.
3. A solid metal inlet for an automatic measuring device for molten metal, characterized by comprising: