JPH01138056A - Hot charging method in pressurizing type molten metal surface holding furnace - Google Patents

Abstract

PURPOSE:To stably execute control operation and to enable control without disturbing molten metal surface level by working controller by opening/closing a supplement control valve and controlling a discharging control valve with reference level sensor and setting level sensor. CONSTITUTION:A molten metal supplement chamber 14 and a molten metal supply chamber 16 are constituted at side parts of a molten metal pressurized chamber 12, and in the pressurized chamber 12, the pressure detecting type reference level sensor 32 for detecting the reference molten metal level Lb in the pressurized chamber 12 is arranged. In the supplement chamber 14, the molten metal supplement hopper 38 for supplementing the molten metal at each fixed quantity through a molten metal supplement control valve 34 is arranged and in the supply chamber 16, a setting level sensor 42 for detecting the molten metal surface level La is arranged. These sensors are connected with the controller 44 building-in a storing device and an operating device. At the time of hot-charging, the controller 44 is worked through opening/closing of the supplement control valve 34 and the discharging control valve 30 is controlled through the reference level sensor 32 and the setting level sensor 42. By this method, quantitative control can be surely executed, and stopping of machine and imperfect work caused by over-charging are prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a pot charging method in a holding furnace for storing molten metal to be supplied to a die-casting machine or the like, particularly in a pressurized molten metal level holding furnace.

[Conventional technology]

Generally, in the casting process of die casting machines, etc.
Accurate control of the amount of hot water supply is required to improve product accuracy and work efficiency.

In general, such quantitative control of hot water supply is performed by controlling the molten metal level in the molten metal supply chamber in the holding furnace to be kept constant (the first method), or by controlling the molten metal level in the furnace according to fluctuations in the molten metal level. Control the internal pressure to a predetermined overall pressure (second
The third method is to control the discharge capacity of the hot water pump so that it is maintained constant even if the hot water level changes (the third method). However, the second method has drawbacks such as the large and heavy furnace body, and the third method
This method has drawbacks such as requiring a complicated control mechanism.

Therefore, in recent years, the first method, which can be constructed relatively lightweight and has a simple control mechanism, has been praised and widely used. The holding furnace of the type box 1 will be briefly described below.

This type of holding furnace has a pressure chamber with a closed top to pressurize the molten metal and a supply chamber with an open top to supply the molten metal (hereinafter referred to as a pressurized molten metal level holding furnace). A supply control valve that supplies pressurized gas into the pressurizing chamber and a discharge control valve that discharges the pressurized gas in the pressurizing chamber to the outside of the furnace are provided, and a set level sensor that detects the set level of the hot water level is installed in the supply chamber. established,
and the supply control valve.

The discharge control valve as well as the set level sensor are connected to the controller. In such a configuration, when molten metal is supplied, the set level in the supply chamber that is lowered by this is detected by the set level sensor, and the supply control valve is opened via the controller to allow pressurized gas to flow into the pressurized chamber. Then, the hot water level in the supply chamber is raised and maintained at a predetermined set level.

On the other hand, when replenishing molten metal, the set level in the supply chamber that is raised by this is detected by a set level sensor, and the discharge control valve is opened via the controller to discharge the pressurized gas in the pressurized chamber to the outside of the furnace. The hot water level in the supply chamber is lowered and maintained at a predetermined set level.

That is, according to this type of pressurized molten metal level holding furnace, the set molten metal level is always kept constant, so that quantitative control of hot water supply can be achieved accurately. Furthermore, since the supply chamber of this type of holding furnace is open, the furnace body is relatively lightweight, and maintenance and inspection of the inside of the furnace can be performed relatively easily. Moreover, the hot water level control mechanism can also be easily constructed.

[Problems that the invention attempts to solve]

However, even in the conventional pressurized molten metal level holding furnace as described above, there are the following difficulties, particularly when replenishing the holding furnace with molten metal, that is, hot charging.

That is, in general, molten metal is supplied from a holding furnace to a die-casting machine or the like in a relatively small amount and on a regular basis, but hot charging to the holding furnace is performed in a relatively large amount [and only temporarily]. For this reason, in the above-mentioned control operation for maintaining the set level of the molten metal in the supply chamber, control during the supply of molten metal is performed stably;
The control during hot charging has the disadvantage of being unstable. That is, during hot charging, the accuracy of holding the set level decreases, and therefore, there is a drawback that quantitative control of hot water supply during this period cannot be accurately achieved.

Furthermore, when hot water is directly charged by a hot water distribution type or the like, overcharging often occurs, making it practically impossible to supply hot water to a die casting machine or the like.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a hot charging method that can replenish molten metal to a pressurized molten metal level holding furnace by overcharging while accurately maintaining the set level of the molten metal. be.

[Means for solving problems]

In order to achieve the above object, the hot chilling method in the pressurized molten metal level holding furnace according to the present invention is such that the molten metal is cooled at the top so as to communicate with the lower part of the molten metal pressurizing chamber along the side wall of the molten metal pressurizing chamber. The replenishment chamber and the molten metal supply chamber are configured, and the pressurization chamber is equipped with a standard level sensor that detects the pressure in the pressurization chamber and detects the standard level of the melt in the pressurization chamber under this pressure. A supply control valve that supplies pressurized gas to the pressurized chamber and a discharge control valve that discharges the pressurized gas in the pressurized chamber to the outside of the furnace are provided, and the molten metal distributed to the replenishment chamber via the molten metal replenishment control valve is supplied to the replenishment chamber. A distribution hopper is provided in which hot water drops in a constant amount, a set level sensor is provided in the supply chamber to detect the set level of hot water, and the standard level sensor, supply control valve, discharge control valve, replenishment control valve, and set level sensor are each controlled by a controller. connect to,
The present invention is characterized in that the controller is actuated during potage by opening and closing a replenishment control valve, and the discharge control valve is controlled by a standard level sensor and a set level sensor.

In this case, the discharge control valve is controlled by a standard level sensor so that the pressure in the pressurized chamber becomes the pressure corresponding to the standard level of molten metal in the pressurized chamber, which should fluctuate as molten metal is replenished, and at the same time detected by the set level sensor. Preferably, the compensation is controlled via the rate of change of the set hot water level in the supply chamber.

[Effect]

The discharge control valve is controlled so that the pressure in the pressurized chamber becomes a preset pressure that should not change over time as the molten metal is replenished, and at the same time is compensated by the rate of change in the set level of the molten metal. Moreover, the molten metal is set to be replenished in fixed amounts at a time. Therefore, the control operation is performed stably and the hot water level setting level is not disturbed during hot charging.

Further, the amount of replenishment of the botchi 17 at one time can be easily and reliably set to a desired amount.

〔Example〕

Next, the hot charging method in a pressurized molten metal level holding furnace according to the present invention will be described with reference to an embodiment of a pressurized molten metal level holding furnace (hereinafter simply referred to as a holding furnace) configured to carry out this method. This will be explained in detail below.

In FIG. 1, a holding furnace 10 for carrying out the hot charging method of the present invention includes a molten metal replenishment material 1 with an open top provided on the side wall of a molten metal pressurizing chamber 12 so as to communicate with the lower part of the pressurizing chamber.
4 and a molten metal supply chamber 16.

In the pressurizing chamber 12, an air supply/exhaust pipe 18 passes through the center of the top thereof, and a communication pipe 20 passes through the side thereof. An air supply pipe 24 connected to a pressure gas source 22 and an exhaust pipe 26 opened to the outside are connected to the air supply/exhaust pipe 18, and each of the ω pipes has a pressurized gas supply control valve 28 such as a solenoid valve. and a pressure gas discharge valve 30 are interposed. Communication pipe 2
0, an If vise detection standard level sensor 32 is installed below the pressure horn P to detect the standard hot water level Lb in the pressurizing chamber 12.

The replenishment chamber 14 is provided above with a distribution hopper 38 for storing molten metal distributed from a distribution pipe 36 with a replenishment control valve 34 interposed therein, and a metering nozzle 40 is provided at the bottom of the distribution hopper 38 Install. The supply chamber 16 has a set hot water level [a
A setting level sensor 42 is provided to detect the.

Then, the aforementioned standard level sensor 32. Supply control valve 28
．． Emission control valve 30. Replenishment control valve 34 and set level sensor 42 are each connected to controller 44 . The controller 44 has a built-in storage device, arithmetic processing device, etc., and, for example, in the illustrated state, a predetermined amount of molten metal is supplied from the distribution hopper 38 to the supply chamber 14 through the metering nozzle 40.
When the molten metal is refilled, the controller 44 adjusts the standard molten metal level 1 in the pressurizing chamber 12 in order to maintain the set molten metal level La in the supply chamber 16 at -. , b to a standard hot water level LC above a predetermined height, the pressure P in the pressurizing chamber 12 can be calculated or stored over time. Alternatively, the rate of change in the set hot water level La can be calculated using the contact and separation time of the set level sensor 42, which detects fluctuations in the set hot water level La, with respect to the hot water level in the supply chamber 16.

In such a configuration, the maintenance control of the set level ``a'' during the supply of molten metal is normally performed in the same way as in the conventional technology described above. That is, when the set level ``la'' falls due to the supply of molten metal, this The setting level sensor 42 detects and the supply control valve 28 is controlled via the controller 44.
is opened and pressurized gas flows into the pressure chamber 12 from the supply/exhaust pipe 18, thereby lowering the standard hot water level Lb in the pressure chamber 12 and raising the set hot water level 1a.

That is, the set hot water level 1-a is maintained constant.

On the other hand, at the time of replenishment of molten metal, that is, hot charging, the controller 44 is activated after a predetermined time by opening the replenishment control valve 34, and the discharge control valve 30 is activated in the pressurized chamber 12, which is detected by the standard level sensor 32 as the replenishment control valve 34 is opened. At the same time, the standard hot water level "b" in the pressurizing chamber 12 is controlled so that the pressure P becomes the pressure that should not change over time, that is, the standard hot water level "b" in the pressurizing chamber 12 becomes the standard hot water level lc that should not change over time. , is further calculated using the contact and separation time of the set level sensor 42 with respect to the hot water level in the supply chamber 16.The set hot water level level la-a
Compensation control is performed by the fluctuation speed of Therefore, the control operation is performed stably, and the set level La of the hot water level is not disturbed during pot charging. Then, when the standard hot water level LC rises to a predetermined position, the replenishment control valve 34
is closed, and the operation of the controller 44 is stopped after a predetermined period of time. Therefore, overchillage of the molten metal does not occur.

Note that the method of controlling the set level of hot water in the hot charging method of the present invention can be applied also when supplying molten metal.

In addition, when molten metal is supplied in parallel during hot charging, calculation processing in the controller is performed based on the amount obtained by subtracting the ml of supplied melt from the replenishment amount in the distribution hopper, rather than the actual replenishment amount. Of course, it can be configured.

Although the present invention has been described above with reference to preferred embodiments, the present invention can be modified in many ways without departing from its spirit.

〔Effect of the invention〕

As explained above, the hot charging method in a pressurized molten metal level holding furnace according to the present invention comprises a molten metal replenishment chamber and a molten metal supply chamber with an open top on the side of the molten metal pressurizing chamber, and pressurizes the molten metal. The chamber is equipped with a pressure-sensing standard level sensor that detects the pressure in the pressurized chamber and detects the standard molten metal level in the pressurized chamber under this pressure, and the molten metal is distributed to the replenishment seedlings via the molten metal/replenishment control valve. By installing a distribution hopper that drops and replenishes the molten metal into the replenishment chamber in a fixed amount at a time, and by installing a setting level sensor in the supply chamber that detects the setting level,
Since the control valve for discharging pressure gas in the pressurizing chamber to reduce the pressure in the pressurizing chamber during discharge can be controlled by both the standard level sensor and the set level sensor, the discharge control valve can be controlled in accordance with the amount of molten metal to be replenished. Therefore, the control operation can be performed stably, the holding furnace can be discharged without disturbing the bloodletting setting level, and overchillation can be reliably prevented.

That is, it is possible to precisely control the amount of Sfl supplied from a holding furnace to a die-casting machine or the like, especially during hot charging, and it is also possible to prevent machine stoppage and unsafe work due to overcharging.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an embodiment of a holding furnace configured to carry out a hot charging method in a pressurized molten metal level holding furnace according to the present invention. 10... Pressurized molten metal level holding furnace 12... Molten metal pressurizing chamber 14... Molten metal supply chamber 1
6... Molten metal supply chamber 18... Supply and exhaust pipe 20.
... Ventilation pipe 22 ... Pressurized gas source 24 ...
- Air supply pipe 26... Exhaust pipe 28... Pressurized gas supply control valve 30... Pressure gas discharge control valve 32... Pressure horn detection type standard level sensor 34... Molten metal replenishment control valve 36 Hot water pipe 38...Hot water distribution hopper 40...Quantitative nozzle 42...Setting level sensor 44...Controller la...Setting hot water level lb, lc...Standard condition level

Claims (2)

[Claims] (1) A molten metal replenishment chamber and a molten metal supply chamber with open tops are constructed so as to communicate with the lower part of the molten metal pressurizing chamber along the side wall of the molten metal pressurizing chamber, and the pressure inside the pressurizing chamber is detected by the pressurizing chamber. A pressure-sensing standard level sensor that detects the standard hot water level in the pressurized chamber under this pressure, a supply control valve that supplies pressurized gas into the pressurized chamber, and an exhaust control that discharges the pressurized gas in the pressurized chamber to the outside of the furnace. A molten metal distribution hopper is provided in which the molten metal distributed through the molten metal replenishment control valve drops into the replenishment chamber in fixed amounts at a time, and a set level sensor is provided in the supply chamber to detect the set molten metal level. The standard level sensor, the supply control valve, the discharge control valve, the replenishment control valve and the set level sensor are respectively connected to a controller, and the controller is actuated through opening and closing of the replenishment control valve during hot charging, and the discharge control valve is connected to the controller. A hot charging method in a pressurized molten metal level holding furnace, characterized in that a control valve is controlled by a standard level sensor and a set level sensor. (2) In the hot charging method according to claim 1, the discharge control valve is configured to adjust the pressure in the pressurizing chamber to a pressure corresponding to a standard level of molten metal in the pressurizing chamber, which should fluctuate as molten metal is replenished. A method of hot charging in a pressurized molten metal level holding furnace, which is controlled by a standard level sensor so that the level of the molten metal is maintained at the same time as the rate of change of the set level in the supply chamber, which is detected by a set level sensor.