JP2004122224A - Method and unit for controlling pouring of molten metal for molten metal pouring facility - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and a unit for easily and accurately controlling pouring quantity of molten metal from a molten metal pouring furnace into a ladle for a molten metal pouring facility. <P>SOLUTION: The molten metal pouring facility is composed of the molten metal pouring furnace 10 having a pouring hole 11 and storing the molten metal, an opening/closing member 14 for opening/closing the pouring hole and the ladle 17 for pouring the molten metal from the furnace into a mold 19. The control unit for controlling the pouring quantity, is composed of detecting means 36, 38 for detecting the increased quantity of the molten metal at each unit time in the ladle, a memory 40 for storing delay time of the opening/closing member and motive pressure acted on the ladle due to the poured molten metal, a calculating means 42 for calculating a preset quantity based on signals from the detecting means and the memory, and output parts 44, 46 for outputting the signal for driving the opening/closing member based on the signal from the calculating means and the set-load of the ladle input from an inputting means 48. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a pouring control method and apparatus for pouring equipment, and more particularly to a method and apparatus for controlling the amount of molten metal poured from a pouring furnace into a ladle.
[0002]
[Prior art]
A pouring device is a device that supplies (pours) a predetermined amount of molten metal to a mold, and includes a pouring furnace (melting furnace) storing the molten metal, a ladle for pouring a predetermined amount of molten metal from the pouring furnace, and the like. including. A predetermined amount of molten metal in the ladle is poured into the mold.
[0003]
It is necessary to pour a predetermined amount of the molten metal in the pouring furnace into the ladle. If the amount of molten metal poured into the ladle, ie, the mold, is too large, the molten metal is wasted. Conversely, if the amount is too small, chippings and cavities occur in a part of the casting. For this purpose, the pouring furnace is tilted to pour the molten metal from the lubrication port on the outer peripheral edge, or the bottom pouring hole is opened by a valve member movable in the depth direction of the pouring furnace to drop the molten metal. In the former, the tilt angle and the shape of the pouring port determine the amount of pouring in the latter, depending on the opening time of the valve member and the shape of the pouring port.
[0004]
Either type has a difficult problem in controlling the amount of pouring from the pouring furnace to the ladle. The return of the pouring furnace or the closing of the valve member is not completed instantaneously and requires a certain time, and the molten metal flows out during the returning or closing. Therefore, when the pouring furnace starts moving backward or closing the valve member when a predetermined amount of pouring has been poured into the ladle, the pouring amount poured into the ladle becomes larger than the predetermined amount. In consideration of this, generally, in anticipation of the amount of molten metal (preset amount) flowing out during the return of the pouring furnace or the closing of the closing member, at a time immediately before the molten metal in the ladle reaches the predetermined amount. The closing of the pouring furnace or the closing of the opening / closing member has begun.
[0005]
For example, in the conventional fixed amount tapping control method shown in FIG. 7 (see Patent Literature 1), a molten metal is transferred from a melting furnace (corresponding to a pouring furnace) 70 tilted by a tilting device 75 to a receiving container (corresponding to a ladle) 71. Lubricate. Here, when the value obtained by subtracting the weight of the molten metal received in the receiving container 71 from the target weight of the molten metal from the melting furnace 70 becomes equal to the expected weight flowing out during the reversion of the melting furnace 71, the reactivation of the melting furnace 71 is started. Has begun.
[0006]
The difference between the current tapping speed Vn and the tapping speed V obtained from the past data, with respect to the actual tapping weight M during the return, obtained from the past data, is defined as a coefficient α. And a value obtained by adding a correction. This can be expressed by the following equation: Mn = M + α × (Vn−V).
[0007]
[Patent Document 1]
JP-A-1-254374
[0008]
[Problems to be solved by the invention]
The actual outflow weight Mn during the return is not always accurate. This constant-rate tapping control method takes into account the fact that the tapping speed of the molten metal changes due to a change in the diameter of the tap hole and a change in the amount of molten metal in the melting furnace 70, and the actual tapping speed M The difference between Vn and tapping speed V obtained from past data is added. However, a method for measuring the current tapping speed Vn and the tapping speed V of the molten metal is not specifically disclosed. It is not easy to accurately measure the tapping speed of the molten metal flowing out of the tilted melting furnace 70.
[0009]
Also, no special consideration is given to the actual outflow weight M during the return movement. The actual outflow weight M during the return movement is obtained by measuring the weight of the receiving container 71 with the sensor 72. However, in addition to the weight of the molten metal poured into the receiving container 71, the kinetic energy (dynamic pressure) of the molten metal falling from the melting furnace 70 affects the measurement, thereby changing the actual weight M flowing out during the return movement. Moreover, the dynamic pressure changes depending on the amount of molten metal in the melting furnace 70.
[0010]
The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a control method and a control device capable of easily and accurately controlling the amount of molten metal poured from a pouring furnace to a ladle.
[0011]
[Means for Solving the Problems]
The inventor of the present application has completed the present invention in view of a method of more easily calculating the amount of molten metal poured from a pouring furnace to a ladle and correcting the calculated value by dynamic pressure or the like.
[0012]
A control method according to a first aspect of the present invention includes a pouring furnace having a pouring port for storing molten metal, an opening / closing member for opening and closing the pouring port, and a ladle for pouring the molten metal poured from the pouring furnace into a mold. , A control method for controlling a pouring amount from a pouring furnace to a ladle in a pouring facility comprising: a detecting step of detecting an increase amount of molten metal in a ladle per unit time; Calculating a preset amount corresponding to the amount of overfilling of the ladle within the operation delay time from the increment amount per unit time and the operation delay time of the opening / closing member stored in the memory; Outputting a signal to close the opening / closing member when the actual measured value of the molten metal in the inside becomes a calculated value obtained by subtracting the preset amount from the set load of the ladle.
[0013]
In this control method, the preset amount is calculated from the calculated weight based on the increment per unit time detected in the detection step and the operation delay time stored in the memory in the calculation step. Then, when the calculated value obtained by subtracting the preset amount from the set weight of the ladle has a predetermined relationship with the measured value, the opening / closing member is closed in the output step.
[0014]
According to a second aspect of the present invention, in the first aspect, the detecting step detects an increase amount per unit time when the amount of molten metal in the ladle is within a predetermined range. According to a third aspect of the present invention, in the first aspect, in the output step, the calculated value is corrected by a dynamic pressure exerted on the ladle by the molten metal to be poured.
[0015]
The control device according to the second invention includes a pouring furnace having a pouring port for storing the molten metal, an opening / closing member for opening and closing the pouring port, and a ladle for pouring the molten metal poured from the pouring furnace into a mold. A control device for controlling a pouring amount from a pouring furnace to a ladle in the pouring equipment comprising: a detecting means for detecting an increase amount of molten metal per unit time in the ladle pan; A memory in which time is stored; calculating means for calculating, based on signals from the detecting means and the memory, a preset amount corresponding to the amount of overfilling the ladle within the operation delay time; An output unit for outputting a signal to close the opening / closing member when the actual weighed value becomes equal to a calculated value obtained by subtracting a preset amount from the set load of the ladle input from the input means.
[0016]
In this control device, the calculating means calculates the preset amount from the increment per unit time detected by the detecting means and the operation delay time stored in the memory. Then, when the calculated value obtained by subtracting the preset amount from the set weight of the ladle has a predetermined relationship with the measured value, the output unit closes the opening / closing member.
[0017]
According to a fifth aspect of the present invention, in the fourth aspect, the opening / closing member moves up and down in the pouring furnace to open and close the pouring port at the bottom of the pouring furnace. According to a sixth aspect of the present invention, in the control device according to the fourth aspect, the detecting means detects whether or not the amount of the molten metal in the ladle is within a predetermined range, and the amount of increase per unit time when the amount is within the predetermined range. And a second detection unit that detects In the control device according to claim 8, in claim 4, the memory further stores a dynamic pressure acting on the ladle by the molten metal to be poured.
[0018]
BEST MODE FOR CARRYING OUT THE INVENTION
<Control method>
(1) Pouring furnace, opening / closing member, ladle
There is a tilting type in which the molten metal is tilted when pouring the molten metal into the ladle, but in the present invention, a type in which the opening and closing member is opened and closed when pouring the molten metal is desirably a non-tilting type. This is because it is difficult to measure the amount of molten metal poured per unit time in the tilting type.
[0019]
The opening / closing member is disposed in the pouring furnace so as to be vertically movable, opens and closes a pouring port opened at the bottom or side, and is driven by a predetermined opening / closing mechanism. The ladle is arranged near the pouring furnace, and pours the poured molten metal into the mold by tilting or the like.
(2) Detection process
The amount of molten metal in the ladle is measured by a weight measuring member such as a load cell. The measured value is an apparent weight including the dynamic pressure described below in addition to the weight of the molten metal in the ladle.
[0020]
The increase amount of the molten metal in the ladle per unit time is poured into the ladle within the time from when the closing command is issued to when the opening / closing member closes the pouring port (hereinafter, referred to as “operation delay time”). Detected to find the over amount. This over amount is stored in the memory as a preset amount, and when the molten metal amount (measured value) in the ladle becomes an amount (calculated value) obtained by subtracting the preset amount from the set load, a stopper closing command is issued. . Then, the molten metal having the set load is poured into the ladle.
[0021]
The amount of increase per unit time may be, for example, the amount of molten metal in a ladle measured by a load cell at predetermined time intervals. However, when the amount of the molten metal is within the predetermined range, the amount of increase can be obtained for each unit time by a simple method by weighing (described later).
(3) Calculation process
In the calculation step, the preset amount is calculated by multiplying the increment per unit time detected in the detection step by the operation delay time of the opening / closing member stored in the memory. The kinetic energy (hereinafter referred to as "dynamic pressure") acting on the ladle by the molten metal to be poured can be stored in a memory.
(4) Output process
In the output step, when the measured value of the molten metal in the ladle becomes a calculated value obtained by subtracting the preset amount from the set load of the ladle, a signal for closing the opening and closing member is issued. That is, the set load is corrected by the preset amount which is the weight data obtained by converting the operation delay time into the weight. Further, the calculated value obtained by subtracting the preset amount from the set load can be corrected by the dynamic pressure.
<Control device>
(1) Detecting means
The detection means may include a first detection unit that detects whether the amount of the molten metal in the ladle is within a predetermined range, and a second detection unit that detects an increase amount per unit time when the amount of the molten metal is within the predetermined range. . The amount of increase per unit time is determined by scanning the molten metal in the ladle every predetermined short time while the molten metal is poured into a predetermined range (for example, the molten metal is poured from 20% to 80% of the set weight of the ladle). A signal is emitted, and the increase between 20% and 80% can be easily divided by the number of scans. If the measurement is performed at 20% or less, the weight of the molten metal measured by a weight measuring member such as a load cell becomes inaccurate due to the impact when the molten metal collides with the ladle.
[0022]
On the other hand, since the preset amount depending on the operation delay time is about 20% of the set load, if the measurement is performed at 80% or more, the weighing is continued even after the measured load exceeds a value obtained by subtracting the preset amount from the set load. That makes no sense.
(2) Memory
The memory stores the operation delay time, dynamic pressure, and the like. The magnitude of the buoyancy acting on the opening / closing member changes depending on the amount of molten metal in the pouring furnace. Therefore, the preset amount can be controlled more accurately by storing the operation delay time according to the molten metal amount. However, since the fluctuation of the buoyancy due to the fluctuation of the molten metal amount is not so large, it is possible to use a delay of the operation time of a fixed length regardless of the amount of the molten metal.
[0023]
Since the magnitude of the dynamic pressure changes depending on the amount of molten metal in the pouring furnace, the dynamic pressure is determined according to the amount of molten metal and stored in a memory. Then, a value corresponding to the molten metal amount at that time is used. In this case, the dynamic pressure at each pouring from the pouring furnace to the ladle may be determined, or the dynamic pressure may be determined at each of a plurality of pouring times, and the same dynamic pressure may be used a plurality of times. good. Further, the amount of drop of the molten metal can be stored in the memory. Here, the "fall amount" is the amount of molten metal that is between the pouring port of the pouring furnace and the ladle when the stopper is closed, that is, is falling.
(3) Calculation means, output unit
The calculating means performs a plus correction when correcting the calculated value obtained by subtracting the preset amount from the set load with the dynamic pressure. This is because the value measured by the load cell or the like is the sum of the actual amount of molten metal in the ladle and the dynamic pressure. If the command is issued at the output unit based on the calculated value corrected by the dynamic pressure, the closing timing of the opening / closing member becomes more accurate.
[0024]
【Example】
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(Constitution)
As shown in FIG. 1, the pouring device includes a pouring furnace (stopper ladle) 10, an opening / closing mechanism 13, a ladle (poiling ladle) 17, a lifting mechanism 22, a tilting mechanism 26, and the like. The pouring furnace 10 is capable of storing several tons of molten metal therein, and has a pouring opening 11 at the bottom. The opening and closing mechanism 13 includes a stopper 14 for opening and closing the pouring port 11 and a stopper cylinder 15 for driving the stopper 14. The opening / closing mechanism 13 is controlled and driven by a PLC (programmable logic controller) 35 described later.
[0025]
The ladle 17 is disposed below the pouring port 11 of the pouring furnace 10 and can store about 100 kg of molten metal. A casting mold 19 is arranged beside and below the ladle 17. The elevating mechanism 21 includes an L-shaped member 22 and a lift cylinder 24. The tip of the horizontal portion 23a of the L-shaped member 22 is connected to the ladle 17, and the upper end of the vertical portion 23b is connected to the lift cylinder 24 arranged in the vertical direction. Therefore, the ladle 17 is moved up and down via the L-shaped member 22 by the expansion and contraction of the lift cylinder 24.
[0026]
The tilt mechanism 26 includes a three-way member 27 and a tilt cylinder 29. Each end of the long part 28a, the intermediate length part 28b, and the short part 28c of the trifurcated member 27 is hinged at one point, and the angle between them is variable. The other end of the long portion 28a is at the lower end of the ladle 17, the other end of the intermediate length portion 28b is at the tilt cylinder 29 connected to the vertical portion 23b, and the other end of the short portion 28c is at the corner of the L-shaped member 22. Each is hinged. Therefore, the ladle 17 is tilted via the three-pronged member 27 by the expansion and contraction of the tilt cylinder 29.
[0027]
The pressing member 31 coupled to the upper end of the lift cylinder 24 presses the load cell 32 attached to the fixing member 33, and the weight of the molten metal in the ladle 17 is measured by the load cell 32 via the L-shaped member 22. You. The output of the load cell 32 is input to the sampling range detector 32 of the PLC 35.
[0028]
FIG. 3 shows the PLC 35. The PLC 35 includes a sampling range detecting section (first detecting section) 36, an increment calculating section (second detecting section) 38 per unit time, a memory 40, a preset amount calculating section 42, a main sequence (CPU) 44, , An output unit 46. The sampling range detection unit 36 detects whether the weight (apparent weight) measured by the load cell 32 gradually increased by pouring into the ladle 17 is in the range of 20 to 40 kg. The increment detecting unit 38 for each unit time calculates the increment of the molten metal in the ladle 17 per unit time (for example, 0.02 seconds). Specifically, the increase amount is obtained by dividing the increase amount of the molten metal of 20 kg (40 kg-20 kg) by the number of scans at 0.02 second intervals while the molten metal amount increases from 20 kg to 40 kg. Detecting means is constituted by the sampling range detecting section 36 and the increment calculating section 38 per unit time.
[0029]
The memory 40 stores a time (operation delay time) until the stopper 14 actually closes the pouring port 11 after the closing signal is given from the output unit 46 to the stopper cylinder 15 and a time when the molten metal in the pouring furnace 10 falls. The kinetic energy (dynamic pressure) applied to the ladle 17 is stored. These are all determined through experiments.
[0030]
The magnitude of the buoyancy acting on the stopper 14 changes as the amount of molten metal in the pouring furnace 10 decreases. In addition, when the molten metal in the pouring furnace 10 falls below a certain limit (for example, several hundred kg) and the molten metal is supplied, the magnitude of the buoyancy changes suddenly. As a result, strictly speaking, the time from when the closing command is issued to when the stopper 14 closes the pouring port 11 changes, and the outflow amount of the molten metal changes. However, in the present embodiment, the operation delay time (for example, 0.46 seconds) measured by experiment under the condition that the molten metal and the like in the pouring furnace 10 are the minimum and the buoyancy acting on the stopper 14 is the minimum is determined by the pouring furnace 10. Used regardless of the amount of molten metal inside.
[0031]
The magnitude of the dynamic pressure acting on the ladle 17 varies depending on the amount of molten metal in the pouring furnace 10. FIG. 4A shows the actual and apparent weights and the elapsed time after the start of pouring when the amount of molten metal in pouring furnace 10 is the smallest (several hundred kg) and the largest (several tons). Shows the relationship.
[0032]
When the amount of molten metal is minimum, the amount of outflow from the pouring port 11 to the ladle 17 is small (see the bending line k in FIG. 4B), and the opening time of the stopper 14 is long (the bending line m in FIG. 4C). It takes time until the ladle 17 is filled, so that the slope of the straight line x indicating the actual weight and the straight line X indicating the apparent weight are gentle. Since there is almost no effect, the straight lines x and X almost overlap with each other, and on the straight line X, the time required for the molten metal in the ladle 17 to increase from 20 kg to 40 kg is represented by C, and the weight increased. By dividing 20 kg by the time C, an increase amount per unit time is obtained.
[0033]
The operation delay time E is obtained from an experiment. The preset amount A is obtained by multiplying the operation delay time E by the increase amount of the molten metal per unit time between the molten metal amounts of 20 to 40 kg. Thus, the operation delay time is converted into weight data. Since the apparent weight and the actual weight are almost the same, the output unit 46 is opened and closed by the operation delay time E earlier than the filling time (time) of the ladle 17 calculated from the increase amount per unit time. By issuing a close command to the ladle 13, the preset amount A is poured into the ladle 17 within the operation delay time E, and the ladle 17 is just filled.
[0034]
On the other hand, in FIG. 4A, the straight lines y and Y represent the actual weight and the apparent weight when the amount of molten metal is the largest. The amount of the molten metal flowing out of the pouring port 11 is large (see the bent line 1 in FIG. 4B), the opening time of the stopper 14 is short (see the bent line n in FIG. 4C), and the ladle 17 is short. , The slopes of the straight lines y and Y are steeper than the straight lines x and X. The kinetic energy of the molten metal is large, and the straight line Y indicating the apparent weight is larger than the straight line y indicating the actual weight in consideration of the influence of the dynamic pressure F.
[0035]
D on the straight line Y indicates the time required for the amount of molten metal in the ladle 17 to increase from 20 kg to 40 kg, and is shorter than the time C. By dividing the increased weight of 20 kg by the time D, the increased amount per unit time is obtained. Here, the operation delay time E is selected to be equal to the operation delay time E when the molten metal amount is the minimum. On the straight line Y, the preset amount B is obtained by multiplying the operation delay time E by the increase amount of the molten metal per unit time between 20 and 40 kg, and is larger than the preset amount A.
[0036]
By the way, looking at the operation delay time E in relation to the straight line y, when the operation delay time E has elapsed, the ladle 17 is not actually completely filled with the molten metal, and an error G has occurred (insufficient). . However, this error G can be obtained by experiment. When the amount of molten metal in the ladle 17 is in the range of 20 to 40 kg, the weight (calculated value) obtained from the increase amount of the molten metal per unit time (0.02 seconds) and the actual amount of the molten metal in the ladle 17 When the error between the weight and the measured value was measured, it was found that there was a certain correlation between the two.
[0037]
As shown in FIG. 5, if the increment per unit time is in the range of 3 to 5 kg, the error falls within the target value of -1 kg to +1 kg, so that no correction is required (the accuracy of the load cell is approximately ± 1 kg). On the other hand, when the increase amount is 5 kg or more, the error becomes -1 kg or less. The relationship between the two may be approximated by a curve using the maximum outflow amount or the like as a change index, and the error G due to the dynamic pressure F may be corrected by adding or subtracting the preset amount B. At this time, if the error when the increase amount is 3 kg is set to +1 kg, the correction due to the error is a minus correction, so that the range of unnecessary correction is expanded.
[0038]
The molten metal of several tons stored in the pouring furnace 10 flows out to the ladle 17 by about 100 kg at each pouring. Repeated ten times. Then, at the end of each pouring, the magnitude of the dynamic pressure is different.
Here, the error due to the dynamic pressure is obtained from the increase amount for each unit time using the above-mentioned approximate expression. When calculation is difficult, dozens of straight lines y and Y created corresponding to the amount of molten metal at each time may be used. Thus, the other cases are calculated based on the case where the amount of molten metal in the pouring furnace 10 is the minimum.
[0039]
Returning to FIG. 3, the operation delay time E, the dynamic pressure F, and the like are input to the memory 40 from an input unit 48 such as a keyboard. Further, a set load (for example, 100 kg) is input from the input unit 48 to the main sequence 44. The preset amount calculation unit 42 determines the over amount of the molten metal, that is, the preset amount by multiplying the increase amount per unit time by the operation delay time, and further increases or decreases the change amount according to the dynamic pressure change index. The main sequence 44 subtracts the preset amount from the preset amount calculation unit 42 from the set load from the input unit 48, compares the measured value with the measurement value input from the sampling range detection unit 36, and outputs the result to the output unit 46 when both are equal. Output a signal. The output unit 46 controls the operation of the opening / closing mechanism 13. The main sequence 44 and the output unit 46 constitute an output unit.
(Action)
As shown in FIG. 1A, the cycle shown in FIG. 6 is started in a state where several tons of molten metal are filled in the pouring furnace 10. At the start, the stopper cylinder 15 is extended and the stopper 14 is lowered to close the pouring port 11. The lift cylinder 24 contracts, the tilt cylinder 29 extends, and the ladle 17 is in a non-tilt state at the raised position. The memory 40 stores the amount of change when the amount of molten metal is the minimum and the amount of change due to fluctuation factors (such as dynamic pressure).
[0040]
The preset calculating unit 38 reads out the amount of change, time, and the amount of change due to fluctuation factors from the memory (S1). Next, the main sequence 44 determines the presence or absence of a weighing start signal (S2). When the weighing start signal is present, the stopper cylinder 15 is contracted by the signal from the output unit 46 and the stopper 14 is raised. Then, as shown in FIG. 1B, the pouring port 11 is opened (S3), and the molten metal in the pouring furnace 10 flows out (falls) into the ladle 17.
[0041]
The amount of molten metal in the ladle 17 is measured by the load cell 32 via the elevating mechanism 22 and the tilting mechanism 26. The sampling range detection unit 36 detects whether the weighed value exceeds 20 kg (S4), and the number of scans from the time when the weighed value exceeds 40 kg is counted by the increase calculation unit 38 per unit time (S5).
[0042]
The sampling range detector 36 determines whether the weighed value exceeds 40 kg (S6), and immediately after the weighing value exceeds 40 kg, the increase calculator 38 calculates an increase in the amount of molten metal for one scan, and thereafter calculates using the increase. (S7). The preset amount detection unit 42 obtains the preset amounts A and B by multiplying the operation delay time from the memory 40 by the increase amount per unit time from the increase calculation unit 38 (S8). The amount of change due to a variation factor (such as dynamic pressure) from the memory 40 is calculated (S9), and the main sequence unit 44 subtracts the preset amount B from the set load to obtain a constant calculated value P (S10).
[0043]
The calculated value P is measured by the load cell 32, and the main sequence 42 determines whether or not the calculated value P is smaller than the gradually increasing measured value (S11). 11 is closed (S12). At the same timing as the stopper 14 closes the extraction port 11, the lift cylinder 24 extends, and the ladle 17 moves downward via the L-shaped member 22 to approach the mold 19. The tilting cylinder 29 contracts, the ladle 17 tilts via the three-way member 27, and the molten metal is poured into the mold 19.
[0044]
After all the molten metal in the ladle 17 has been poured into the mold 19, each cylinder and each member operate in the opposite direction to that described above, and one cycle is completed. Thereafter, this cycle is repeated at each pouring from the pouring furnace 10 to the ladle 17.
(effect)
According to the embodiment described in detail above, the following effects can be obtained.
(1) The amount of pouring from the pouring furnace 10 to the ladle 17 can be easily obtained by the control method and the control device. This is because, instead of calculating the speed of pouring from the pouring furnace to the ladle as in the conventional example, the amount of increase in the amount of pouring per unit time in the ladle 17 is detected. Moreover, when detecting the increase amount per unit time, instead of directly calculating the increase amount, the number of scans when the pouring amount in the ladle 17 is 20 to 40 kg is counted, and the increased 20 kg is counted. And ask for it. Therefore, the calculation is simplified.
[0045]
Further, since the operation delay time E is set to be constant in consideration of the small influence of the difference in the amount of molten metal in the pouring furnace 10 on the buoyancy, the curves y and Y except when the amount of molten metal is the minimum are set. Etc. can be easily obtained.
(2) The amount of pouring from the pouring furnace 10 to the ladle 17 can be accurately obtained. This is because, when calculating the calculated value P, the dynamic pressure caused by the drop of the molten metal is taken into consideration. Since the value measured by the load cell 32 is positively corrected by the dynamic pressure obtained for each amount of molten metal in the pouring furnace 10 through the experiment, the amount of molten metal in the ladle 17 can be accurately calculated.
(3) The amount of pouring from the pouring furnace 10 to the ladle 17 can be controlled in real time. In FIG. 6, a constant calculation value P is obtained in S10 from the preset amount obtained in S4 to S8 and the dynamic pressure called from the memory 40 in S9. At this point, the ladle 17 is being poured.
[0046]
Then, when the calculated value P becomes smaller than the measured value gradually increased by pouring, in other words, when the measured value becomes larger than the calculated value, a signal to close the stopper 14 is issued. In this way, the amount of molten metal in the ladle 17 is measured as needed, and when the calculated value is in a predetermined relationship, a close command is issued, so that the ladle 17 can be filled with the molten metal.
(4) The time required for one cycle can be shortened. Since the preset amount of this embodiment is smaller than the preset amount of the conventional example, the operation delay time of the stopper 14 can be shorter than the return time of the receiving container 70. Further, the ladle 17 is moved and tilted toward the mold 19 at the same timing as when the stopper 14 closes the pouring port 11. As a result, each cycle can be completed in a short time. A short cycle time is also desirable to prevent the temperature of the molten metal from lowering.
{Circle around (5)} It is possible to suppress fluctuations in the outflow amount of the molten metal due to impurities (sticks) attached to the stopper 14 and the pouring port 11. If the impurities adhere to the stopper 14 or the like, the vertical position of the stopper 14 at the time of closing is changed, thereby changing the outflow speed. In addition, there is generally no close relationship between the adhesion of impurities and the amount of molten metal, and it is difficult to predict the timing of adhesion of impurities.
[0047]
However, in the present invention, the increasing amount of the molten metal per unit time in the ladle 17 is measured instead of measuring the outflow velocity of the molten metal as in the conventional example. Therefore, when an impurity adheres, a smaller increase is measured, and the preset amount is calculated based on the increase, so that it is not affected by the impurity adhesion.
[0048]
【The invention's effect】
As described above, according to the control method of the first invention, the outflow amount is calculated based on the increase amount of the molten metal per unit time in the detection step. Control of the amount of hot water is simple. In addition, since the calculation process corrects the calculated operation delay time obtained by the experiment with the preset amount converted into weight data, the pouring amount control is accurate.
[0049]
According to the second aspect, the calculated value can be obtained accurately. According to the third aspect, the control of the pouring amount becomes more accurate.
[0050]
According to the control device of the second aspect of the present invention, since the detecting means calculates the outflow amount based on the increase amount of the molten metal per unit time, control of the pouring amount is simpler than in the case of calculating the outflow speed. It is. In addition, since the calculation means corrects the operation delay time obtained by the experiment by the preset amount converted into weight data, the control of the pouring amount is accurate.
[0051]
According to the fifth aspect, it is easy to measure the outflow amount of the molten metal from the pouring furnace to the ladle.
[0052]
According to claim 6, it is easy to calculate the increase amount of the molten metal per unit time. According to claim 7, the calculation of the increase amount of the molten metal becomes more accurate. According to the eighth aspect, the calculated value of the dynamic pressure is accurately calculated regardless of whether the amount of molten metal in the pouring furnace is large or small.
[Brief description of the drawings]
FIG. 1 (a) is an explanatory view showing a main part of a control device of a pouring facility according to the present invention, showing a start state, and FIG. 1 (b) is an explanatory view showing a pouring state to a ladle 17, similarly.
2 (a) is an explanatory view showing a state where the pouring into the ladle 17 of the control device is completed, and FIG. 2 (b) is an explanatory view showing a state where pouring into the mold 19 is also performed.
FIG. 3 is an explanatory diagram showing a PLC of the control device.
4A is a graph showing a relationship between an actual measured value and an apparent measured value and an elapsed time, FIG. 4B is a graph showing a relationship between an outflow amount from a pouring port 11 and an elapsed time, and FIG. () Is a graph showing the relationship between the opening and closing of the stopper 14 and the elapsed time.
FIG. 5 is a graph showing a relationship between an increase amount per unit time and a measurement error in the embodiment.
FIG. 6 is a flowchart showing the operation of the embodiment.
FIG. 7 is an explanatory view showing a main part of a conventional example.
[Explanation of symbols]
10: Pouring furnace 13: Opening / closing mechanism
14: Stopper 17: Ladle
19: Mold 21: Lifting mechanism
24: Lift cylinder 26: Tilt mechanism
29: tilt cylinder 32: load cell
35: PLC 36, 38: detecting means
40: Memory 42: Preset amount calculation unit
44, 46: output means 48: input means

Claims (8)

In a pouring facility comprising a pouring furnace having a pouring port and storing a molten metal, an opening / closing member for opening and closing the pouring port, and a ladle for pouring the molten metal poured from the pouring furnace into a mold. A control method for controlling a pouring amount from a furnace to a ladle,
A detection step of detecting an increase amount of the molten metal in the ladle per unit time,
A preset amount corresponding to an over-amount poured into the ladle within the operation delay time is obtained from the increase amount per unit time detected in the detection step and the operation delay time of the opening / closing member stored in the memory. Calculation process to be determined;
An output step of outputting a closing signal of the opening and closing member when an actual measured value of the molten metal in the ladle becomes a calculated value obtained by subtracting the preset amount from a set load of the ladle,
A control method characterized by comprising: The control method according to claim 1, wherein the detecting step detects an increase amount per unit time when the amount of molten metal in the ladle is within a predetermined range. The control method according to claim 1, wherein in the output step, the calculated value is corrected by a dynamic pressure exerted on the ladle by the molten metal to be poured. In a pouring facility comprising a pouring furnace having a pouring port and storing a molten metal, an opening / closing member for opening and closing the pouring port, and a ladle for pouring the molten metal poured from the pouring furnace into a mold. A control device for controlling a pouring amount from a furnace to a ladle,
Detecting means for detecting an increase amount of the molten metal per unit time in the ladle,
A memory in which the operation delay time of the opening / closing member is stored;
Calculating means for calculating a preset amount corresponding to an over-amount to be poured into the ladle within the operation delay time, based on a signal from the detecting means and the memory;
When the actual measured value of the molten metal in the ladle becomes equal to a calculated value obtained by subtracting the preset amount from the set load of the ladle input from the input means, a signal for driving the opening and closing member is provided. An output unit for outputting,
A control device comprising: The control device according to claim 4, wherein the opening / closing member moves vertically in the pouring furnace to open and close a pouring port at a bottom of the pouring furnace. The said detection means includes a 1st detection part which detects whether the amount of the molten metal in the ladle is in a predetermined range, and a 2nd detection part which detects the increase amount per unit time when it is in a predetermined range. Item 5. The control device according to Item 4. The control device according to claim 6, wherein the predetermined range is 20% to 80% of a set weight of the ladle. The control device according to claim 4, wherein the memory further stores a dynamic pressure acting on the ladle by the molten metal to be poured.

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