JPH04279273A - Method for controlling pouring molten metal - Google Patents

Abstract

PURPOSE:To improve accuracy of pouring control for molten metal into a receiving ladle from a pouring furnace. CONSTITUTION:When the detected wt. WDE after stopping the pouring at each time of the pouring control is out of the range between the upper limit aimed wt. WOH and lower limit aimed wt. WOL, based on the detected wt. WDE after stopping the pouring and the difference between the above upper limit and lower limit aimed wts. WOH, WOL, a correct setting wt. WSC is made to obtain. In the case of the pouring control at a first time, the setting wt. WS in pouring stop is set to the pouring aimed wt. WO. In the case of the pouring control at a second time and after this, when the detected wt. WDE after stopping the pouring in the case of the pouring control at the previous time is in the above range, the setting wt. WS in the pouring stop at the previous time is used to the pouring control at the next time. When the detected wt. WDE in the pouring stop at this time is out from the above range, the average value of the correct setting wt. WSC at this time and the setting wt. WS in the pouring stop obtd. at each pouring control in the setting time till the previous time, is decided as the setting wt. WS in the pouring stop at the next time.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention involves pouring molten metal into a receiving pot from a pouring furnace, detecting the weight of the poured metal into the receiving pot with a weight detector, and detecting the weight detected by the weight detector when the molten metal stops pouring. The present invention relates to a pouring control method in which pouring from a pouring furnace is stopped when a set weight is reached.

0002

[Prior Art] Conventionally, the amount of molten metal poured from a pouring furnace into a receiving pot is detected by a load cell serving as a weight detector, and when the value detected by the load cell reaches a set value, the pouring from the pouring furnace is stopped. For example, Japanese Patent Application Laid-open No. 59-10
This is already known from Publication No. 0826 and the like.

0003

[Problems to be Solved by the Invention] However, there is a time lag between when the detected value of the load cell reaches the set value and when pouring actually stops, and when pouring from the pouring furnace to the pot starts, the pot does not close. It is difficult to accurately control the amount of molten metal poured into the receiving pot due to load cell detection errors caused by the impact force received, and in the past, an error of about 3% was unavoidable.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a pouring control method that enables more accurate pouring control of pouring from a pouring furnace to a receiving pot. .

[0005]

[Means for Solving the Problems] In order to achieve the above object, according to the present invention, a pouring target weight, an upper limit target weight and a lower limit target weight sandwiching the target weight are set in advance, For each pouring control, it is checked whether the weight detected by the weight detector after pouring is within the range between the upper limit target weight and the lower limit target weight, and the weight detected after pouring is within the range. If it is off, the set weight for stopping pouring is corrected based on the difference between the detected weight after stopping pouring and the upper limit target weight and lower limit target weight to obtain a corrected set weight, and in the first pouring control. sets the pouring stop set weight as the pouring target weight, and when performing pouring control from the second time onwards, if the detected weight after pouring stop during the previous pouring control is within the above range, the previous pouring control weight is set as the pouring target weight. The stop set weight is maintained as it is and used for the next pouring control, and if the detected weight after the current pouring is out of the above range, the corrected set weight obtained this time and the obtained value for each pouring control of the set number of times up to the previous time are used. The average value of the molten metal pouring stop setting weight and the molten metal pouring stop setting weight is determined as the molten metal pouring stop setting weight for the next pouring control.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to a ductile cast iron manufacturing apparatus will be described below with reference to the drawings.

FIGS. 1 and 2 show an embodiment of the present invention, with FIG. 1 being a schematic diagram of a casting apparatus, and FIG. 2 being a flowchart showing a pouring control procedure.

First, in FIG. 1, a receiving pan 5 into which a prescribed amount of Mg powder 4 has been charged is installed below the tap 3 of a pouring furnace 1 storing molten metal 2. By opening the molten metal and pressurizing the inside of the pouring furnace 1, molten metal 2 is poured from the tap 3 into the receiving ladle 5. When a predetermined amount of molten metal 2 is poured into the receiving ladle 5, the pouring from the tap 3 starts. The hot water is stopped, and molten ductile cast iron is poured from the receiving ladle 5 into a mold (not shown).

The pouring furnace 1 is equipped with an inlet 7 that can be opened and closed with a lid 6, and with the lid 6 open, molten metal from a ladle (not shown) is injected into the pouring furnace 1 from the inlet 7. be done. Further, a conduit 8 is connected to a position above the surface of the molten metal 2 in the pouring furnace 1, and an electromagnetic switching control valve is used to selectively communicate or shut off the conduit 8 with the pressurized air source 10 and the atmosphere. It can be switched by 9. When the conduit 8 is connected to the pressurized air source 10 by the electromagnetic switching control valve 9 with the inlet 7 closed by the lid 6, the inside of the pouring furnace 1 is pressurized and the molten metal 2 flows through the outlet 3.
When the conduit 8 is opened to the atmosphere, the molten metal 2 in the pouring furnace 1 is stopped from being tapped from the tap 3.

A rod-shaped stopper 11 is inserted through the tap 3 and is movable between a lower position for closing the tap 3 and an upper position for opening the tap. An actuator 12 such as a cylinder is connected. Then, by pressurizing the inside of the pouring furnace 1 with the stopper 11 pulled out from the tap 3 by the actuator 12, pouring from the tap 3 into the receiving ladle 5 is started, and the actuator 12 pulls the stopper 11 out of the tap. 3, the pouring of metal from the tap 3 into the receiving pot 5 is stopped.

Load cells 13 as a plurality of weight detectors are used to measure the amount of molten metal poured into the receiving pot 5 from the outlet 3.
are arranged to support the saucepan 5, and the detected values of these load cells 13 are input to a control unit C consisting of a computer. Thus, the control unit C controls the operation of the electromagnetic switching control valve 9 and the actuator 12 based on the detected values from each load cell 13.

Next, the pouring control procedure preset in the control unit C will be explained with reference to FIG. 2. In the first step S1, it is determined whether the flag F is "0". This flag F indicates whether or not this is the first pouring control, and the flag F is set to "0" during the first pouring control. When it is determined in the first step S1 that the flag F is "0", the process proceeds to the second step S2, and the target weight WO of molten metal to be poured from the pouring furnace 1 into the receiving pot 5 is stopped. It is set as the set weight WS. Further, when the flag F is "1", that is, during the second and subsequent pouring control, the second step S2
The process bypasses the process and proceeds to the third step S3.

In the next third step S3, pouring from the pouring furnace 1 is started, and in the fourth step S4, the detected weight WD of the molten metal in the receiving ladle 5 is determined based on the detected value of each load cell 13.
It is determined whether or not is equal to the pouring stop set weight WS, and only when WD = WS, the process proceeds to the fifth step S5 and pouring from the pouring furnace 1 to the receiving pot 5 is stopped. .

By the way, when starting pouring, molten metal may fall or M
Since the impact force associated with the explosive reaction with g powder 4 acts on the receiver ladle 5, errors are likely to occur in the detection values of each load cell 13, but after the pouring is stopped, the molten metal surface in the receiver ladle 5 also The detected value by each load cell 13 is accurate when the machine is stationary, and after the pouring is stopped, the detected weight WDE after the pouring is stopped is obtained based on the detected value of each load cell 13. On the other hand, the lower limit target weight WOL is lower than the pouring target weight WO by the allowable amount.
is set in advance, and in the sixth step S6, it is determined whether the detected weight WDE after stopping pouring is larger than the lower limit target weight WOL (WOL<WDE), and WOL<WD
If it is E, the process advances to the seventh step S7. Also, the upper limit target weight WOH is higher than the pouring target weight WO by the allowable amount.
is set in advance, and in the seventh step S7, it is determined whether the detected weight WDE after stopping pouring is smaller than the upper limit target weight WOH (WDE<WOH), and if WDE<WO
If it is H, the process advances to the eighth step S8. That is, the detected weight WDE after stopping pouring is within the range defined by the lower limit target weight WOL and the upper limit target weight WOH (WOL
When <WDE<WOH), the process proceeds to the eighth step S8 and the flag F is set to "1".

If it is determined in the sixth step S6 that the detected weight WDE after stopping pouring is less than or equal to the lower limit target weight WOL (WDE≦WOL), the process proceeds to a ninth step S9. Then, in the ninth step S9, the value obtained by subtracting the detected weight WDE after stopping pouring from the lower limit target weight WOL (WOL - WD
A calculation is performed in which 1/2 of E) is set as the correction value εL, and in a tenth step S10, a calculation is performed in which the correction value εL is added to the pouring stop setting weight WS to obtain the corrected set weight WSC.

In the eleventh step S11, the flag F is set to "
0", and when the flag F is "0", that is, it is the first pouring control, the eighth
The process advances to step S8, and when the flag F is "1", the process advances to the twelfth step S12.

In the twelfth step S12, the average value of the sum of the corrected set weight WSC and the pouring stop setting weight WS obtained during the previous pouring control (WSC+WS), that is, 1/2, is the next pouring stop setting. The weight is set as the weight WS, and the process then proceeds to the eighth step S8.

When it is determined in the seventh step S7 that the detected weight WDE after stopping pouring is equal to or higher than the upper limit target weight WOH (WOH≦WDE), the process proceeds to a thirteenth step S13, and in a thirteenth step S9, the pouring Detected weight after stopping WDE
The value obtained by subtracting the upper limit target weight WOH from (WDE-WOH
) is executed as the correction value εH,
In the fourteenth step S14, a calculation is performed to obtain the corrected set weight WSC by subtracting the correction value εH from the set weight WS to stop pouring, and the process further proceeds to the eleventh step S11.

In the eleventh step S11, the flag F is set to "
0", and when the flag F is "0", that is, it is the first pouring control, the eighth
The process advances to step S8, and when the flag F is "1", the process advances to the twelfth step S12.

To summarize such a control procedure, for the first pouring control, the pouring stop set weight WS is set to the pouring target weight WO, and for the second and subsequent pouring controls, the previous pouring control is set. If the detected weight WDE after stopping pouring during hot water control is within WOL<WDE<WOH, the previous set weight WS for stopping pouring is maintained and used for the next pouring control, and the current weight detected after stopping pouring is maintained. Weight WDE is WDE≦W
When OL or WOH≦WDE, the average value of the corrected setting weight WSC obtained this time and the pouring stop setting weight WS obtained for each previous pouring control, that is, 1/2, is used as the pouring point for the next pouring control. This will be determined as the set stop weight WS.

Next, the operation of this embodiment will be explained. When pouring metal from the pouring furnace 1 into the receiving pot 5, each load cell 13
When the weight WD of molten metal in the receiving pan 5 based on the detected value reaches the pouring stop setting weight WS, the operation of the actuator 12 and the electromagnetic switching control valve 12 is controlled by the control unit C, and the flow from the pouring furnace 1 is controlled by the control unit C. Pouring of hot water into the receiving pot 5 is stopped.

Moreover, the set weight WS to stop pouring metal is first set to the target weight WO, and the detected weight WDE after the pouring stop based on the detected value obtained by each load cell 13 after the pouring stop is equal to the target weight WO. It is confirmed for each pouring control whether the weight is within the range between the sandwiched upper limit target weight WOH and lower limit target weight WOL, and the detected weight WDE after stopping pouring during the previous pouring control was within the above range. Sometimes, the previous pouring stop setting weight WS is maintained as it is and used for the next pouring control, and when the detected weight WDE after pouring stop is out of the range, the detected weight WDE after pouring stop and the upper limit target weight are set. The corrected set weight WSC obtained by correcting the pouring stop set weight WS based on the difference between AXH and the lower limit target weight AXL and the pouring stop set weight WS obtained during the previous pouring control.
The average value of the molten metal pouring stop setting weight WS for the next molten pouring control
By defining as, the detected weight WDE after stopping pouring
It is possible to control the pouring so that WOL<WDE<WOH, and the conventional error was 3%, but it is now 1%.
It becomes possible to improve control accuracy until the error is reduced to a certain degree.

In the above embodiment, the detected weight WD after stopping pouring
When E is out of the above range, the current correction setting weight W
SC and pouring stop setting weight WS obtained during the previous pouring control
The average value of the molten metal pouring stop setting weight WS for the next molten pouring control
However, the pouring stop setting weight WS obtained every two or more pouring controls up to the previous time is memorized, and
The average value of the set pouring stop weight WS and the current corrected set weight WSC may be determined as the next set pouring stop weight WS.

Furthermore, the present invention can be implemented not only in ductile cast iron manufacturing equipment but also in a wide variety of casting equipment.

[0025]

As described above, according to the present invention, a pouring target weight, an upper limit target weight and a lower limit target weight sandwiching the target weight are set in advance, and the weight is adjusted for each pouring control. It is checked whether the weight detected by the detector after stopping pouring is within the range between the upper limit target weight and the lower limit target weight, and if the weight detected after stopping pouring is out of the range, the weight after stopping pouring is checked. The pouring stop set weight is corrected based on the difference between the detected weight and the upper limit target weight and lower limit target weight to obtain the corrected set weight, and the pouring stop set weight is used for the first pouring control. When the target weight of hot water is set, and the weight detected after stopping the pouring during the previous pouring control is within the above range, for the second and subsequent pouring control, the previous set weight for stopping pouring is maintained as it is. It will be used for the next pouring control, and if the detected weight after the current pouring is out of the above range, the corrected set weight obtained this time and the pouring stop set weight obtained for each set number of pouring controls up to the previous time will be used. Since the average value is determined as the pouring stop setting weight for the next pouring control,
Control accuracy can be improved by controlling the amount of molten metal poured into the receiving pan so that the weight of the molten metal falls within a certain range.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of a casting apparatus according to an embodiment.

FIG. 2 is a flowchart showing a pouring control procedure.

[Explanation of symbols]

1 Pouring furnace 2 Molten metal 5 Receiving pot 13 Load cell WD as a weight detector
Detected weight WDE Detected weight after stopping pouring WO Target pouring weight WOH Upper target amount WOL Lower target weight WS Pouring stop set weight WSC Correction set weight

Claims (1)

[Claims] Claim 1: Pour the molten metal (2) from the pouring furnace (1) into the receiving pot (5), and detect the weight of the poured metal into the receiving pot (5) with a weight detector (13), The weight detected by the detector (13) (WD) is the pouring stop set weight (WS)
In the pouring control method, the pouring from the pouring furnace (1) is stopped when the target weight of pouring (WO) is reached.
and the upper limit target weight (WO ) sandwiching the target weight (WO ).
H) and the lower limit target weight (WOL) are set in advance, and the weight detected after pouring stop (WDE) by the weight detector (13) for each pouring control is equal to the upper limit target weight (WOL).
) and the lower limit target weight (WOL), and the detected weight after stopping the pouring (WD).
When E) is out of the range, the pouring stop set weight (WS ) is corrected based on the difference between the detected weight after pouring has stopped (WDE) and the upper target weight (WOH) and lower target weight (WOL). to obtain the corrected set weight (WSC), and in the first pouring control, the pouring stop set weight (WS) is set to the target pouring weight (WO), and the second
For subsequent pouring control, if the detected weight after pouring stop (WDE) during the previous pouring control is within the above range, the previous pouring stop setting weight (WS) will be maintained as it is for the next pouring. It is used for hot water control, and when the current detected weight after pouring stop (WDE) is out of the above range, the corrected set weight (WSC) obtained this time and the pouring stop setting obtained for each previous set number of pouring controls are used. A pouring control method characterized in that the average value of the weight (WS ) is determined as the pouring stop setting weight (WS ) for the next pouring control.