JPH0787983B2 - Pressure level control device for pressure pouring furnace - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a level control device for a pressurized pouring furnace having a pouring port with a quantitative shot device, and more particularly, during pouring and / or pouring. The present invention relates to a level control device for a pressurized pouring furnace, which can stably maintain the level of the level of the pouring spout and can control the opening / closing frequency of the on-off valve provided in the air supply control line or the exhaust control line to a minimum. .

[Conventional technology]

Conventionally, a pouring port, a pouring port, and a pressurizing chamber are connected in a siphon shape at the bottom of the furnace body, a pressurizing gas pipe line is provided in the pressurizing chamber, and a pressurizing gas from the pressurizing gas pipe line into the pressurizing chamber is provided. The pressurized pouring furnace in which the molten metal stored in the furnace body is pressurized by the supply of air, and the molten metal is poured from the pouring port into the mold is disclosed in, for example, JP-A-56-19968. It is publicly known as described in JP-A-102369, JP-A-55-97865 and JP-A-49-2719.

In addition to the above configuration, the publication describes a molten metal level control device for a pressurized pouring furnace having the following configuration.

In Japanese Patent Laid-Open No. 56-19968, a fixed quantity shot device (a pouring nozzle with a stopper) is provided at the pouring port and a molten metal level detection sensor is provided, and a signal from this molten metal level detection sensor is sent to the pressurized gas pipeline. There is described a molten metal level control device for a pressurized pouring furnace, which controls the pressurized gas in a pressure chamber by transmitting it to a provided pressurized gas control device.

In Japanese Patent Laid-Open No. 56-102369, a pressure compensating flow path connected to the same high-pressure air body source is provided in parallel with the pressurized air introducing system path, and a pressure reducing valve is provided in this pressure compensating flow path. Further, there is described a level control device of a pressurizing pouring furnace in which a flow rate adjusting valve is provided and the opening degree of the flow rate adjusting valve is adjusted by a pressure signal in a pressurizing chamber.

In Japanese Patent Laid-Open No. 55-97865, two pouring level detection rods are provided at the pouring port, and a first exhaust system and a second exhaust system are provided at the exhaust system. One of the detection rods is the one for detecting the molten metal level during pouring, and the other one is the rod for detecting an abnormal rise in the pouring port
During one shot of pouring, when the surface of the pouring spout comes into contact with the pouring surface detecting rod, the variable throttle mechanism of the booster relay is stopped and the pressure at that time is maintained, and the gas pressure in the pressurizing chamber is maintained. When the water level of the pouring port drops and the pouring port is not in contact with the pouring-during-water level detection rod, the booster relay is activated to increase the pressure, and the gas pressure in the pressurizing chamber is increased until it contacts again, and this is repeated. By controlling the pouring surface during pouring, when one shot is completed, the first and second exhaust systems are released to exhaust the gas pressure in the pressurizing chamber to atmospheric pressure, and the pouring surface of the pouring port is A pouring control device for a pressure pouring furnace that drops to a free state is described.

Japanese Unexamined Patent Publication No. 49-2719 discloses a molten metal level detector having two detectors at a pouring port, and an air supply device and an exhaust device provided in a pressurized gas line. The exhaust device is provided with a sub-air supply line and a sub-exhaust line each having a throttle valve and an opening / closing valve, the gas flow rate is controlled by the throttle valve, and the molten metal level signal from the detector is opened / closed. A molten metal level control device for a pressurized pouring furnace, which transmits to a valve to control the supply / exhaust of pressurized gas in the pressurized chamber and holds the molten metal level at the pouring port between two detectors. Have been described.

[Problems to be Solved by the Invention]

As mentioned above, various types of level control devices for pressurized pouring furnaces have been developed.However, in the conventional level control devices, the on-off valve was opened by the signal from the level detector to control the level of the pouring port.・ When the molten metal is poured into a plurality of molds prepared in advance by intermittently pouring the molten metal into each of the molds, open / close the open / close valve of each mold to melt the molten metal at the pouring port. The surface level must be raised and lowered, and since leakage compensation in the pressurizing chamber is not accurately performed, the on-off valve must be operated to maintain the molten metal surface level other than during pouring. At the same time as the hot water cycle takes a long time, the operating frequency of the on-off valve increases, and there is a problem that reliable surface control is difficult to obtain due to problems such as the on-off valve itself or increased gas leakage from the on-off valve.

In view of the above problems, the present invention stably holds the molten metal surface level of the pouring port at the time of pouring and / or receiving hot water, and is provided in the air supply control pipeline or the exhaust control pipeline. It is an object of the present invention to provide a scene control device for a pressurized pouring furnace, which can control the opening / closing frequency of the open / close valve as low as possible.

[Means for Solving the Problems]

In order to achieve the above object, in the molten metal surface level control device for a pressurized pouring furnace of the present invention, a main pipe into the furnace body is composed of an air supply control pipe and an exhaust control pipe, and a pouring port upper opening portion. A surface level control device for a pressurized pouring furnace, which is equipped with a surface level detector on the pouring side and a fixed quantity shot device at the pouring port, wherein the air supply control line is an on-off valve for air supply and a flow rate setting for air supply. Valves and a gas supply pressure adjusting valve on the upstream side of the gas flow, and a leakage compensating pipe line equipped with an electric flow control valve is attached to the air supply control pipe line, and the air supply opening / closing is provided. The valve is controlled to be closed when the level control detector of the level control of the level detector provided at the upper opening of the pouring port is in contact with the level, and the flow rate setting for supply is set. The air supply flow rate of the valve is set to be almost equal to the pouring flow rate of the constant shot device.

[Action]

Since the leakage compensation pipeline equipped with the electric flow control valve is attached to the air supply control pipeline, the flow rate setting valve installed in the air supply control pipeline regardless of the leakage flow rate of gas from the pressurizing chamber etc. The air supply flow rate can be set to be almost the same as the pouring flow rate, and the air supply flow rate can be made to be almost the same as the pouring flow rate regardless of the pressure in the pressurizing chamber by the pressure adjusting valve provided in the air supply control pipeline. It can be controlled so that it can be maintained.

Further, an air supply on-off valve is provided in the air supply control line, and a water level controller for air supply control is provided in the metal level detector at the pouring port. The open / close frequency of the open / close valve is almost equal to or equal to the number of shots because the open / close valve for air supply can be controlled to be closed when in contact, and leakage compensation is performed. It can be reduced to the following frequencies:

〔Example〕

Hereinafter, embodiments according to the present invention will be described with reference to the drawings.

In the figure, 1 is a pouring port 2, a receiving port 3 and a pressurizing chamber 4.
It is a furnace body consisting of. Reference numeral 5 denotes a molten metal level detector provided at an upper opening of the pouring port 2, and includes a molten metal level detector 6 for air supply control and a molten metal level detector 7 for exhaust control. Further, the pouring port 2 is provided with a quantitative shot device 10 including a stopper 8 and a pouring nozzle 9. Reference numeral 11 is a main pipeline having an air supply control pipeline 12, a leakage compensation pipeline 13 and an exhaust control pipeline 14 and communicating with the pressurizing chamber 4 of the furnace body 1. Then, in the air supply control line 12, the differential pressure regulating valve 1
5, solenoid valve 16 and flow setting needle valve 17 are provided,
In addition, a solenoid valve 18 and an electric flow control valve 19 are provided in the leakage compensation line 13 from the upstream side of the air supply.

On the other hand, in the present embodiment, the exhaust control conduit 14 is also provided with a constant pressure adjusting valve 20, a solenoid valve 21, and a flow rate setting needle valve 22 from the exhaust upstream side.

Reference numeral 23 is a control device, which is based on the input of the molten metal level detector 5 and the like, the air supply solenoid valve 16, the leakage compensation solenoid valve 18, the electric flow control valve 19, the exhaust solenoid valve 21, and the fixed quantity shot device 10. It controls the opening and closing of.

Further, reference numeral 24 is a surge tank provided in the air supply control conduit 12 for covering pressure fluctuations caused by a sudden flow rate change.

Further, 25 is an exhaust gas filter provided in the exhaust control pipeline 14, and is for protecting each valve provided in the exhaust control pipeline 14.

Next, the operation of the molten metal level control device of the pressure pouring furnace having the above-described structure will be described.

Set the flow rate of the flow rate setting needle valve 17 of the air supply control line 12 (flow rate in consideration of expansion due to temperature in the pressurizing chamber) to almost the same amount as the pouring flow rate during shot, and The pressure difference between the inlet side and the outlet side of the flow rate setting needle valve 17 was set by adjusting the differential pressure adjusting valve 15 so as to maintain a constant differential pressure in addition to the pressure applied to the pressurizing chamber 4. After that, the hot water was received to obtain the initial state of pouring as shown in the figure.

Then, first, in order to start pouring, the solenoid valve 21 of the exhaust control line 14 is closed, and the solenoid valve 16 of the air supply control line 12, the solenoid valve 18 of the leakage compensation line 13 and the electrically operated flow control valve are closed. By opening 19, the pressure in the pressurizing chamber 4 is increased, the molten metal in the pouring port 2 and the receiving port 3 rises, and when it contacts the level control sensor 6 for air supply control, the signal is received and the air is supplied. The solenoid valve 16 of the control line 12 closes. Next, from this state, the stopper 8 of the fixed-quantity shot device 10 is opened and closed to perform pouring of each shot.
The solenoid valve 16 is opened by and is kept open during the shot. As a result, during the shot, a supply air flow rate that is substantially equal to the pouring flow rate during the shot is supplied to the pressurizing chamber 4, and the leakage amount that changes as the molten metal level in the pressurizing chamber 4 changes during the shot, Leakage compensation control is performed by intermittently operating the electric motor of the electric flow control valve 19 to control the opening / closing speed of the valve, so that the level of the molten metal at the pouring port 2 is maintained at a substantially constant level. The frequency of opening / closing operation of the solenoid valve 16 can be set to a necessary minimum, that is, a frequency substantially equal to the number of shots.

Next, the operation of the exhaust control pipeline 14 will be described.

As described above, the pouring is repeated, the molten metal in the pressurizing chamber 4 decreases, and it is inferred from the pressure in the pressurizing chamber 4 that the pouring is performed before the pouring controllable limit is exceeded. In this case, the molten metal is supplied to the hot water inlet 3, but this raises the level of the molten metal at the pouring port 2.
The exhaust control metal level detector 7 is brought into contact with the exhaust control solenoid valve 21, and the exhaust solenoid valve 21 of the exhaust control line 14 is opened by the signal of the contact to lower the molten metal level. When the molten metal level is lowered and separated from the exhaust gas level controller 7 for exhaust control, the electromagnetic valve 21 for exhaust is closed again, and the molten metal level of the pouring port 2 rises. This is repeated during hot water supply to the hot water inlet 3, and a predetermined amount of hot water can be supplied to the furnace body 1 regardless of the state during pouring or when pouring is stopped. During this hot water supply, the exhaust control line 14
The exhaust flow rate of the exhaust flow rate setting needle valve 22 (flow rate considering expansion in the pressurizing chamber due to temperature) is set to the hot water supply flow rate almost in advance, and the constant flow rate adjusting valve 20 is used to set the exhaust flow rate setting needle valve 22. By keeping the pressure on the inlet side of the exhaust gas at a constant pressure, the exhaust flow rate of the exhaust flow rate setting needle valve 22 can be maintained substantially constant regardless of the change in the pressure of the pressurizing chamber 4, so that the exhaust solenoid valve 21 during hot water reception. The frequency of opening and closing can be reduced.

In addition, if the pressure in the pressurizing chamber 4 rises and the molten metal comes into contact with the molten metal when the molten metal level detector 7 for exhaust control is pouring other than when the molten metal is being received, Similarly, control can be performed by opening the electromagnetic valve 21 for exhaust and lowering the molten metal surface of the pouring port 2.

Although one embodiment of the device of the present invention has been described above, the configuration and use of the device of the present invention are not limited to this embodiment.

For example, in the leakage compensation line 13 of the device of the present invention, the solenoid valve
Although the example in which the electric flow control valve 18 and the electric flow control valve 19 are provided has been described, a double pressure adjusting valve may be provided upstream of the electric flow control valve 19 to cope with pressure fluctuation.

Also, in the usage of the device of the present invention, in the embodiment, the case where the air supply solenoid valve 16 is opened at the same time as the start of the shot is described, but after the shot, the molten metal leaves the air level control detector 6 for air supply control. Even if the air supply solenoid valve 16 is opened and controlled from the above, the same effect can be obtained.

Further, in the device of the present invention, it is possible to provide a rapid air supply conduit in the air supply control conduit 12 to expedite the rise of the molten metal surface at the initial stage of the molten metal pouring and shorten the time required to prepare the molten metal. In addition, the exhaust control line
14 is provided with a rapid exhaust pipe line, and the molten metal level detector 5 is provided with an abnormal molten metal level detector for the exhaust control molten metal level detector 7.
It is also possible to provide it at a higher position and perform rapid exhaust control when the molten metal surface of the pouring port 2 rises abnormally due to a trouble or the like.

〔The invention's effect〕

According to the above-described present invention, since the leakage compensation pipeline including the electric flow control valve is provided in the air supply control pipeline, the pressurized gas flow rate including the leakage amount can be accurately adjusted, and hand,
Since the air supply on-off valve is controlled to be closed when the surface level detector for air supply control at the pouring port is in contact with the surface of the water, the frequency of opening and closing the air supply on-off valve can be reduced. The life of the air supply on-off valve is also improved.

Further, the present invention, since it is possible to stably control the surface of the molten metal of the pressure pouring passage, while increasing the operating rate of the pressure pouring furnace,
Workability is also greatly improved.

[Brief description of drawings]

The figure is a partial cross-section control function diagram of an embodiment of the device of the present invention. 1 ... Furnace body, 2 ... Pouring port, 3 ... Receiving port, 4 ... Pressurizing chamber, 5 ... Level level detector, 6 ... Level control sensor for air supply control, 7 ... Exhaust control hot water Surface level detector 8 …… Stopper, 9 …… Pouring nozzle 10 …… Quantitative shot device, 11 …… Main pipeline 12 …… Supply control pipeline, 13 …… Leakage compensation pipeline 14 …… Exhaust control pipeline , 15 …… Differential pressure adjusting valve 16,18,21 …… Solenoid valve 17,22 …… Flow rate setting needle valve 19 …… Electric flow control valve 20 …… Constant pressure regulating valve, 23 …… Control device

Claims (1)

[Claims] 1. A main pipe into the furnace body is composed of an air supply control pipe and an exhaust control pipe, and a molten metal level detector is provided at an upper opening of the pouring port, and a fixed quantity shot device is provided at the pouring port. A surface level control device for a pressurized pouring furnace, wherein the air supply control conduit includes an air supply on-off valve, an air supply flow rate setting valve, and a gas supply pressure adjusting valve on the upstream side of the gas flow. In addition, a leakage compensating line equipped with an electric flow control valve is provided along with the air supply control line, and the air supply on-off valve is a level controller for a water level provided at the upper opening of the pouring port. Is controlled to be closed when the hot water level detector for air supply control is in contact with the hot water surface, and the air flow rate of the air flow rate setting valve is set to be substantially equal to the pouring flow rate of the quantitative shot device. A molten metal level control device for a pressure pouring furnace.