JP2001138032A - Control method for pouring molten metal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a control method of pouring molten metal which is suitable to high speed pouring of the molten metal and can contribute to the improvement of the productivity. SOLUTION: This control method of pouring the molten metal, is the one, in which a vessel having a pouring hole and holding the molten metal and a tilting device for tilting the vessel, are used and the molten metal is poured into a mold from the pouring hole in the vessel by tilting the vessel with the tilting device and a command for stopping of pouring the molten metal, is outputted accompanied with the completion of pouring the molten metal into the mold to return back the tilting. A molten metal weight detecting means for detecting the present weight of the molten metal in the vessel, is used and when the molten metal is poured in each mold, the present weight of the molten metal in the vessel at least in the latter half period on the way of pouring the molten metal into one mold from the pouring hole in the vessel, is obtained. The difference between this present weight and the weight of the molten metal in the vessel at the stopping of pouring the molten metal in the other one of the mold poured just before the one of the mold is obtained, and when this difference reaches the setting value, the commands for stopping of pouring the molten metal P1, P2, P3... are outputted to the tilting device for pouring the molten metal to return back the tilting of the vessel.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of pouring a molten metal into a mold from a spout of the container by tilting a container holding the molten metal, and also, when the pouring of the molten metal into the mold is completed, drains the molten metal into a tilting pouring device. The present invention relates to a pouring control method for outputting a command to return tilt.

[0002]

2. Description of the Related Art In a pouring process of a casting line, a tilting pouring device for tilting a container is used, and the molten metal is poured into a mold from a spout of the container by tilting the container with the tilting pouring device. During pouring, it is necessary to pour a certain amount of molten metal into the mold. Therefore, whether or not the pouring into the mold has been completed is generally determined by measuring the level of the molten metal such as the gate of the mold or the riser with a level sensor or relying on the naked eye of a person. Since the level sensor uses a laser beam,
The cost is high, and the sensing control is not easy. Even when relying on the naked eye of a human, accuracy is insufficient.

Conventionally, a weight sensor for detecting the weight of molten metal in a container is provided, the weight of molten metal before and after pouring in the container is measured, and the actual weight of molten metal poured into a mold is detected. Is also known.

[0004]

As described above, when the weight of the molten metal before and after pouring in the container is measured by the weight sensor, if the surface of the molten metal in the container is oscillating, the oscillation may occur. The weight of the molten metal in the container detected by the weight sensor fluctuates considerably due to, for example, the influence of the inertial force of the melt. For this reason,
It is necessary to wait for a considerable period of time until the surface of the molten metal in the container is calmed down and the fluctuation of the molten metal surface becomes small. For this reason, pouring time for pouring into one mold becomes long,
There was a limit to improving productivity.

[0005] In particular, in the case of a type in which the container tilts around a rotation center provided near the spout of the container, the level of the molten metal in the container fluctuates greatly due to the pouring operation.
The time required for calming the molten metal surface is long, and if the molten metal surface waits for calming, the pouring time for pouring into one mold becomes considerably long, and the productivity decreases.

[0006] In recent years, the molding speed of a molding apparatus such as a frameless molding apparatus has been increasingly increased. In order to incorporate a pouring device into a molding line of a molding device that has been accelerated in this way and perform pouring, high-speed pouring is required so as not to delay the molding speed.
Therefore, in a high-speed molding line, a pouring control method in which the pouring time required for one mold is long is not preferable.

[0007] The present invention has been made in view of the above circumstances, and has as its object to provide a pouring control method suitable for high-speed pouring and capable of contributing to an improvement in productivity.

[0008]

Under the above-mentioned problems, the present inventors have been keenly developing a pouring control method suitable for high-speed pouring, and as one of the methods, a method for controlling pouring in a container such as a ladle is required. A technology using molten metal weight detection means for detecting the weight of molten metal has been developed. In the first half of the pouring, in which the molten metal is poured into the mold from the spout of the container, the surface of the molten metal in the container fluctuates greatly in the first half, but in the second half of the pouring, the molten metal in the container is in the second half. It was found that the swing of the molten metal surface in the container was quite calm, despite the fact that the weight of the melt was decreasing every moment. Then, in the latter half of the pouring process, the current weight of the molten metal in the container during the pouring is obtained, and the current weight and the weight of the molten metal in the container at the time of pouring in the mold pouring immediately before the mold are calculated. When the difference is obtained, and when the difference reaches the set value, a running-out command, which is a command to stop pouring, is output to the tilting pouring device so as to return the tilting of the container. The present inventors have found that the accuracy of the determination of the out-of-water instruction can be ensured while shortening the required time, and that the accuracy of the pouring weight per mold can be ensured.

That is, the pouring control method according to the present invention comprises:
Using a container having a spout and holding the molten metal, and a tilting pouring device for tilting the container, the molten metal is poured from the spout of the container into the mold by tilting the container with the tilting pouring device. And, in the pouring control method of returning the tilt by outputting a run-out command to the tilting pouring device with the end of pouring into the mold, using molten metal weight detecting means for detecting the weight of the molten metal in the container, In pouring the molten metal into each of the molds, the current weight of the molten metal in the container in at least the latter half of the pouring in which the molten metal is being poured into one mold from the spout of the container is determined, and the current weight and the current The difference between the weight of the molten metal in the container and the weight of the molten metal in the container at the time of draining of the other mold poured immediately before one mold is determined. To return the tilt of the container to It is an.

In the latter half of the pouring of the molten metal into the mold, unlike in the first half of the pouring, the swing of the molten metal in the container is reduced, and the molten metal surface is considerably stabilized. Therefore, the accuracy of the current weight of the molten metal by the molten metal weight detecting means is more stable than in the first half of the middle of pouring. For this reason, the determination accuracy of the pouring out command which is the pouring end command is ensured.

[0011] Further, in order to output a running-out command based on the current weight of the molten metal in the container measured during the pouring, the pouring operation and the weight measurement of the molten metal are performed in parallel. Therefore, the time for actually pouring the mold and the time for measuring the weight of the molten metal in the container overlap, and the time required for the entire operation of pouring the mold into the mold is reduced.

Further, since the surface of the molten metal in the container is stable in the latter half of the middle of pouring, the accuracy of the current weight of the molten metal in the container is secured in the latter half, and the difference described above is reduced.
It can be regarded as the pouring weight per one mold.

[0013]

According to a preferred embodiment of the method of the present invention, after the tilting of the container is returned, the sedation standby step of waiting until the oscillation of the molten metal in the container is sufficiently quenched is performed without performing the following sedation standby step. Start pouring hot water.

As described above, in the latter half of pouring the molten metal into the mold, the swing of the molten metal in the container is considerably reduced, and the surface of the molten metal in the container is considerably stabilized. Therefore, the accuracy of the current weight of the molten metal in the container by the molten metal weight detection means is ensured even during the pouring.

As the current weight of the molten metal in the container, if the instantaneous weight value of the molten metal changes frequently, the average value of the instantaneous weight values can be used, or the instantaneous weight value does not change much. In that case, the instantaneous weight value itself can be adopted.

According to a preferred embodiment of the method of the present invention, one pouring operation is performed by a large tilting speed operation performed until the molten metal is discharged from the spout of the container, and the molten metal is discharged from the spout of the container. It is possible to adopt a configuration including a tilting speed low operation executed later and a tilt return operation for returning the tilt of the container in response to the out-of-water instruction.

The operation of increasing the tilting speed is performed at the beginning of the pouring operation, and the tilting speed of the container is high, so that the time required for the pouring operation can be shortened. The tilting speed low operation is performed after the initial stage of the pouring operation, and the tilting speed of the container is low. As described above, the large tilting speed operation is performed in the early stage of the pouring operation, and the small tilting speed operation is performed after the initial stage of the pouring operation (that is, in the middle period or the end period). In the latter half of the bath, the swing of the molten metal in the container can be reduced to stabilize the surface of the molten metal in the container. Therefore,
The time required for one pouring operation can be reduced while ensuring the measurement accuracy for measuring the current weight of the molten metal in the container in the latter half of the pouring.

Generally, in a graph in which the horizontal axis represents time and the vertical axis represents the weight of molten metal in a container, the instantaneous weight value of the molten metal in the container in the latter half of the pouring operation is calculated by Compared to the first half, although the amplitude that fluctuates up and down is small, it shows a vibration waveform that vibrates up and down to some extent. The main reason that the instantaneous weight value oscillates is that the fluctuation of the molten metal surface in the container affects the measurement of the instantaneous weight value of the molten metal.

For this reason, the instantaneous weight value of the molten metal in the container is measured over an integral multiple of the period of the vibration waveform.
A configuration in which the average value of the measured instantaneous weight values is regarded as the current weight can be adopted. In this case, since the instantaneous weight value of the molten metal in the container is measured over an integral multiple of the period of the vibration waveform, even when the instantaneous weight value of the molten metal in the container vibrates up and down, Now can improve the accuracy of weight.

The term "period" means the time required for one wavelength of the vibration waveform. Therefore, if the frequency of the vibration waveform is f [Hz], the cycle is 1 / f [second]. Although the frequency and cycle vary depending on the type of container and the type of molten metal, generally, the frequency of the above-mentioned vibration waveform is 1 to 20.
[Hz], especially 3-5 [Hz], and the period is 0.05.
１1 [sec], particularly 0.2 to 0.33 [sec].

The molten metal weight detecting means used in the present invention detects the weight of the molten metal in the container, and measures the weight of the molten metal in the container together with the weight of the container itself as a total weight.
Means for subtracting the weight of the container itself from the total weight can be employed. Although the weight of the molten metal in the container gradually decreases as the number of times of pouring increases, the weight of the container itself can be basically regarded as constant. Can be weighed. A load cell can be adopted as a typical molten metal weight detecting means.

The material of the mold is not particularly limited, and a sand mold can be generally used, but a mold may be used in some cases. In the case of a frameless molding line, high-speed pouring is particularly required because a frameless mold is molded at a high speed.

A typical container in the present invention is a ladle. The capacity of the container is not particularly limited. For example, a ladle for 100 kg to 20 t in weight can be adopted,
It is not limited to this. Examples of the molten metal held in the container include an iron-based molten metal such as cast iron, cast steel, and stainless steel, and a non-ferrous molten metal such as an aluminum alloy and a copper alloy.

[0024]

Embodiments of the present invention will be described below with reference to the drawings. This embodiment is an example applied to a pouring control method in a frameless molding line. In this embodiment, as shown in FIG. 1, a large number of sandless frameless molds 10 are continuously molded at high speed by a molding apparatus 1, and are conveyed in series in the direction of arrow A1. Although it differs depending on the type of the molding apparatus 1, the time for molding one mold 10 is generally 8 hours.
It is a short time of up to 12 seconds, and high-speed molding is performed. Therefore, in order to pouring with one container 2 held by one pouring tilting device, the pouring time to the mold 10 is shortened so as not to be delayed by the molding speed of the molding device 1 which performs high-speed molding. It is preferable to carry out in time. The mold 10 has a gate 10c, which is a pouring port into which the molten metal in the container 2 described later is poured.

The container 2 contains a high-temperature molten metal (a molten metal for cast iron, 1).
It is a ladle that holds (about 300 to 1500 ° C.). The container 2 includes a steel shell 20 having an upper surface opening, a refractory layer 21 lined on the inner surface of the steel shell 20, and a guideway 22 projecting laterally outward.
And a spout 23 provided at the tip of the guide path 22. In the vicinity of the spout 23 of the container 2, a tapping sensor 38 for detecting discharge of the molten metal from the spout 23 is provided by a holder (not shown).

The center of rotation when the container 2 is tilted is indicated by the axis OP. As described above, in the present embodiment, since the container 2 tilts around the axis OP provided near the spout 23 of the container 2, the position of the center of gravity of the entire container 2 changes considerably with the pouring operation, and The swing of the molten metal in the container 2 due to the hot water operation is large.

As shown in FIG. 2, the tilting pouring device 3 holds the container 2 and tilts the container 2. The tilting pouring device 3 includes a tilting gear 33 that is a rack having a receiving plate 31 held on a base 8 via a load cell 30 and a plurality of teeth 33 c held by the receiving plate 31. Body 34 and a drive motor 35 disposed on the receiving board 31
And a tilt sensor 36 arranged on the receiving board 31 for detecting the tilt angle of the container 2, and a tooth portion 37 c meshing with the tilt gear 33
Having a pinion 3 which is driven to rotate by a drive motor 35
7 is provided. The container 2 is detachably held by the tilting body 34. When the drive motor 35 rotates forward and the pinion 37 rotates forward, the tilting body 33 swings in the direction of the arrow H1 while the tilting gear 33 meshes with the pinion 37, whereby the container 2 tilts about the axis OP. The molten metal is discharged from the spout 23. When the drive motor 35 rotates in the reverse direction, the tilting body 34 swings around the axis OP in the direction of arrow H2, the tilting of the container 2 is returned, and the discharge of the molten metal from the spout 23 stops.

The load cell 30 functions as molten metal weight detecting means, and includes a container 2 holding the molten metal, a receiving plate 3
Measure the total weight of peripheral equipment such as 1st. When the molten metal is poured, the weight of the molten metal in the container 2 gradually decreases, but the weight of the container 2 itself and the weight of peripheral devices such as the receiving plate 31 do not basically change and are fixed values. Even if the total weight including the weight of the molten metal is measured, the instantaneous weight value of the molten metal itself held in the container 2 is measured.

A control device 5 for controlling the tilting pouring device 3 is provided. The control device 5 includes a drive circuit 50 for driving the drive motor 35, a control circuit 52 for controlling the drive circuit 50, and a memory 53. The control circuit 52
It has an input processing circuit to which various signals are input, a CPU having an arithmetic function and a counting function, and an output processing circuit which outputs a control signal to the drive circuit 50. Various signals such as a weight signal measured by the load cell 30, a tilt angle signal of the container 2 measured by the tilt sensor 36, and a hot water signal from the hot water sensor 38 are input to an input processing circuit of the control circuit 52 of the control device 5. Is done.

FIG. 3 schematically shows a change in the tilting speed of the container 2 in the pouring operation according to the present embodiment. The horizontal axis of FIG. 3 indicates time, and the vertical axis of FIG. 3 indicates a tilting speed (tilting angular speed). In FIG. 3, the region above the horizontal axis indicates the tilting speed of the container 2 in the direction of pouring (arrow H1 direction), and the region below the horizontal axis indicates the direction in which the container 2 tilts back (arrow H2). (Direction) of the container 2 is shown. As shown in FIG. 3, one pouring operation is performed from a start time t0 to a time t2 at which the molten metal is discharged from the spout 23 of the container 2 and the tilting speed of the container 2 is large, and
A tilting speed small operation performed after time t2 when the molten metal is discharged from the spout 23 of the container 2 and the tilting speed of the container 2 is small,
Includes a tilt return operation that is executed in response to the running out command Pt and returns the tilt of the container 2.

The drainage command Pt is a command for stopping the pouring of the molten metal from the spout 23 of the container 2, and is output from the control device 5 to the tilting pouring device 3. In this way, if the tilting angle of the container 2 is increased by performing the tilting large operation in the initial stage of the pouring operation of one pouring operation, the pouring speed can be increased. Further, if the tilt angle of the container 2 is reduced by performing the tilting small operation after the initial pouring, the swing of the molten metal in the container 2 can be suppressed in the latter half of the pouring operation.

The change in the tilting speed of the container 2 in one pouring operation will be further described. In the present embodiment, specifically, as shown in FIG. 3, at the beginning of the pouring operation, first, from time t0, which is the start time of the pouring operation, to time t1.
Over a performs the accelerating operation A1 that the tilting speed of the vessel 2 to the speed increasing approximately linearly to velocity V _H 0. From the time t1 when inclining speed reaches the speed V _H, the time at which that molten metal from the spout 23 container 2 has been discharged is detected at time t2
Until then, a high-speed holding operation A2 for holding the tilting speed of the container 2 constant or almost constant at the speed _VH , which is a high-speed stage, is performed. If the tilting speed is increased in this manner, the pouring operation can be shortened. The discharge of the molten metal from the spout 23 of the container 2 is detected by the tapping sensor 38 described above.

Thereafter, from time t2 to time t3, the container
The tilting speed of 2 is the speed V_HTo speed V_LDeceleration maneuvering down to
Work A3 is performed. With the deceleration, the swing of the molten metal in the container 2
Can be suppressed. Thereafter, from time t3, the tilting speed is reduced to a low speed.
Speed V, which is the stage_L(V_L<V _H) Constant at low speed
A conversion operation A4 is performed. At the stage of the low-speed stabilizing operation A4,
The molten metal is continuously discharged from the spout 23 of the vessel 2,
Is poured into the gate 10c. Low speed stabilization operation A4 has elapsed
As it is gradually shifting to the latter half of the middle of pouring
As the level of the molten metal in the container 2 gradually decreases,
The swing of the molten metal surface in the vessel 2 gradually becomes smaller,
The level of the molten metal in the container 2 is stabilized.

As described above, after the low-speed stabilizing operation A4 elapses, and the process proceeds to the latter half of pouring, pouring into the mold 10 proceeds, so that the pouring weight into the mold 10 gradually increases. The pouring operation gradually approaches the end.

In order to end the pouring, a tilt return operation A5 for returning the tilt of the container 2 is performed from time t4 when the running out command Pt is output to the tilt pouring device 3. At the time t5, tilting back speed is the speed V _r. Further, from time t5 to time t6, a tilt return operation A6 for decreasing the tilt speed from the speed _Vr to 0 is performed so that the tilt return is gradual.
At time t6, the tilting return operation A6 of the container 2 has been completed. As described above, one pouring operation is performed at time t0 to time t6.
It is done in. The above-described pouring operation is repeatedly performed many times until the molten metal in the container 2 is almost empty.

By the way, in this embodiment, the moment of the molten metal in the container 2 is changed from before the first pouring operation is started until the end of the last pouring operation, that is, until the molten metal in the container 2 is almost empty. The weight value is continuously measured every measurement unit time (for example, can be set to 10 msec, but is not limited to this). Therefore, in this embodiment, the instantaneous weight value of the molten metal in the container 2 is continuously measured both in the first half of the middle of the pouring of each pouring operation and in the second half.

FIG. 4 is a graph showing the relationship between the change in the instantaneous weight of the molten metal in the container 2 and the tilting speed of the container 2 when the pouring operation is repeated. In FIG. 4, a change in the instantaneous weight value of the molten metal in the container 2 is shown as a characteristic line W.

In this embodiment, the melt weight Wn0 before the start of the pouring operation is obtained in advance. The melt weight Wn0 is an average value of a plurality of instantaneous weight values before the pouring operation is started. Then, 1
The current weight Wn1 of the molten metal in the container 2 in the latter half of the middle of the second pouring operation is determined. As the pouring process progresses,
As shown by the characteristic line W in FIG. 4, the molten metal in the container 2 decreases and the surface of the molten metal in the container 2 fluctuates.
The instantaneous weight value of the molten metal inside changes every moment. As will be described later, the current weight Wn1 (Wn1 <Wn0) is based on the average value of a plurality of instantaneous weight values measured for each measurement unit time.

In the first pouring operation, the difference (Wn0-Wn1) between the melt weight Wn0 before the start of the pouring operation and the current weight Wn1 of the molten metal in the latter half of the pouring operation is determined.
Then, the difference (Wn0-Wn1) is compared with a preset value Wb. In this example,
In the first pouring operation, set value Wb is set, and in the second and subsequent pouring operations, set value Wc is set.

If it is determined that the measured difference (Wn0-Wn1) from the current weight Wn1 in the second half has reached the set value Wb, it is considered that pouring has been completed, and the control device 5 issues a run-out command Pt.
₁ is output to the tilting pouring device 3. Therefore, tilting pouring device 3
Is used for returning the tilting operation of the container 2,
5. Execute A6. Furthermore, when the hot water is drained (the hot water drain command Pt
The weight of the molten metal in the container 2 at the time of (output ₁ ) is input to the memory 53 as Wf1.

In the present embodiment, the description “Before starting the pouring operation”
The difference between the melt weight Wn0 and the current weight Wn1 (Wn0-Wn
1) has reached the set value Wb ”.
To go. That is, as described above,
The instantaneous weight of the molten metal is measured in a unit time (for example, 10 msec).
c) The measurement is continuously performed every time. And multiple instantaneous weights
Quantity value W₁, W_Two, W_Three, W_Four, W_Five... W_SAverage value Wn1₁
(Wn1₁<Wn0). Melt before starting pouring operation
Weight Wn0 and average value Wn1₁(Wn0-Wn1) ₁)
And the set value Wb. Difference (Wn0
-Wn1₁) Has reached the set value Wb, the control device 5
Is a software or hardware counter count
Increase the number of events by one. Difference (Wn0-Wn1₁) Is the set value W
If it does not reach b, increase the count of the counter
Do not let.

[0042] Furthermore the instantaneous weight value shifting one, predetermined number of instantaneous weight value _{W 2, W 3, W 4} , W 5 ...... W S, W S + 1 average value Wn1 ₂ a (Wn1 ₂ <Wn0) Ask. The difference between the melt weight Wn0 before the start of the pouring operation and the average value Wn1 ₂ (W
If n0−Wn1 ₂ ) has reached the set value Wb, the count number of the counter is further increased by one. Difference (Wn0-
If Wn1 ₂ ) has not reached the set value Wb, the count of the counter is not increased. Furthermore, the instantaneous weight value is 1
The individual instantaneous weight values W ₃ , W ₄ , W ₅ ... W _S ,
The average value Wn1 ₃ (Wn1 ₃ <Wn0) of _{WS + 1} and WS _{+ 2} is obtained, and the melt weight Wn0 and the average value Wn1 ₃ before the pouring operation is started.
If the difference (Wn0−Wn1 ₃ ) has reached the set value Wb, the count number of the counter is further increased by one. If the difference (Wn0-Wn1 ₃₎ has not reached the set value Wb, it does not increase the count of the counter.

The instantaneous weight values thus measured are sequentially shifted to obtain an average value, that is, a moving average value Wn1 _n is sequentially obtained, and the difference between the molten metal weight Wn0 before starting the pouring operation and each moving average value Wn1 _n is obtained. When (Wn0−Wn1 _n ) reaches the set value Wb, the counter counts a predetermined number (for example, 20 times,
50 times or 100 times), “the weight Wn0 of the molten metal before the start of the pouring operation and the current weight W at the time of the first pouring operation”
n1 (Wn0-Wn1) has reached the set value Wb. "

As a result, the control circuit 52 of the control device 5 outputs the out-of-water instruction Pt ₁ . If the count number of the counter is less than the predetermined number, “the molten metal weight Wn before the start of the pouring operation”
0 and the current weight Wn1 at the time of the first pouring (Wn0
−Wn1) has reached the set value Wb ”. Therefore, the control circuit 52 of the control device 5 outputs the hot-water command Pt.
Do not output ₁ .

As described above, in the present embodiment, since the method using the moving average value is employed, it is possible to suppress occurrence of error detection due to the specific instantaneous weight value. That is, in the present embodiment, the weight of the molten metal in the container 2 is measured while discharging the molten metal from the spout 23 of the container 2. Although much more stable than in the period, it is often not completely sedated. Thus, even when the molten metal is not completely calmed down, the fact that the difference between the weight of the molten metal in the container 2 before the start of the pouring operation and the current weight of the molten metal in the container 2 has reached the set value Wb, Accurate detection is possible.

When the first pouring operation is completed as described above, the second casting mold 10 is conveyed to the pouring point, so that the second casting mold 10 is poured into the second casting mold 10. Perform hot water operation promptly. In this case, unlike the prior art,
The second pouring operation is immediately started without performing the sedation standby step of waiting until the oscillation of the molten metal in the container 2 has calmed down after returning the tilt of the container 2 on which the first pouring operation has been performed. .

In the second pouring operation, the current weight Wn 2 (Wn 2 <
Wf1) is obtained. As described above, the current weight Wn2 is based on the average value of a plurality of instantaneous weight values measured for each measurement unit time. In the second pouring, the current weight Wn2
And the weight Wf1 of the molten metal in the container 2 at the time of the previous hot draining of the mold 10 poured immediately before the mold 10 (W
f1−Wn2). Then, the preset value Wc is compared with the difference (Wf1−Wn2). Difference (Wf
If it is determined that 1−Wn2) has reached the set value Wc, 2
Control device 5 outputs tilting pouring device 3 to run-out command Pt ₂ , which is a stop command for the _second pouring. As a result, the tilt pouring device 3 returns the tilt of the container 2. That is, the tilt return operations A5 and A6 are executed. Further, the difference (Wf1
−Wn 2) is determined as the weight of the molten metal poured into the second mold 10.

The determination that "the difference (Wf1-Wn2) has reached the set value Wc" is made in the same manner as described above. That is, even in the second pouring, the instantaneous weight value of the molten metal in the container 2 is continuously measured every measurement unit time (for example, 10 msec). And a plurality of instantaneous weight values W ₁ , W ₂ , W ₃ , W ₄ , W
₅ average value of _{...... W S Wn2 1 (Wn2 1} <Wf1) seek. The weight Wf1 and average value W of the molten metal in the container 2 at the time of the last hot water draining
n2 ₁ and the difference between the (Wf1-Wn2 _1), is compared with the setting value Wc. If the difference (Wf1−Wn2 ₁ ) has reached the set value Wc, the count of the counter is increased by one. If not, the count of the counter is not increased.

The instantaneous weight value is further shifted, and
Weight value W_Two, W_Three, W_Four, W_Five... W_S, W_{S + 1}Average value Wn of
Two_Two(Wn2_Two<Wf1) is determined. And the difference (Wf1-W
n2 _Two) Has reached the set value Wc, the counter
The number of events is further increased by one. If not,
Do not increase the count of the counter.

The instantaneous weight value is further shifted so that a predetermined number of instantaneous
Weight value W_Three, W_Four, W_Five... W_S, W_{S + 1}, W_{S + 2}Average value of W
n2_Three(Wn2_Three<Wf1) is determined. And the difference (Wf1−
Wn2_Three) Has reached the set value Wc, the counter
Increase the number of unds by one.

The average obtained by sequentially shifting the instantaneous weight values in this manner.
Value, that is, the moving average value Wn2_nSequentially,
Weight Wf1 and moving average value of molten metal in container 2 when draining water
Wn2 _n(Wf1-Wn2)_n) Reaches the set value Wc
The count of the counter is a predetermined number of times (for example,
If it is 0 times or 100 times or more, the difference (Wf1−W
n2) has reached the set value Wc ".

Thus, control device 5 outputs the second run-out command Pt ₂ to tilting pouring device 3. As a result, the tilt pouring device 3 returns the tilt of the container 2. During the second hot cutting the weight of the container 2 the molten metal (when outputting the hot water out command Pt ₂₎ is input to the memory 53 as Wf2. If the number of times of the counter is less than the predetermined number, no out-of-water instruction Pt ₂ is output.

After the second pouring is completed as described above, the third mold 10 is conveyed to the pouring point, and the third pouring is performed to pour the third mold 10. Perform the operation. In this case, the container 2 in which the second pouring operation was performed
, The third pouring operation is started without performing a sedation waiting step of waiting until the swing of the molten metal in the container 2 is calmed down. Then, the current weight Wn3 of the molten metal in the container 2 in the latter half of the third pouring operation.
(Wn3 <Wf2) is determined. As described above, the current weight Wn3 is obtained based on the average value of a plurality of instantaneous weight values measured for each measurement unit time. In the third pouring, the difference (Wf2−Wn3) between the current weight Wn3 and the weight Wf2 of the molten metal in the vessel 2 at the time of the previous pouring of the mold 10 poured immediately before the mold 10 is calculated. Ask. Then, upon reaching the difference (Wf2-Wn3) a set value Wc which is set in advance, the control device 5 the third hot water out command Pt ₃ of outputs to tilt pouring device 3. As a result, the tilt pouring device 3 returns the tilt of the container 2. The weight of the molten metal in the container 2 at the time of the third draining is input to the memory 53 as Wf3. Furthermore,
The difference (Wf2-Wn3) is determined as the weight of the molten metal poured into the third mold 10.

In the third pouring operation, the difference (Wf
2−Wn3) has reached the set value Wc ”.
In the same manner as described above, the calculation is performed with the count number where the moving average value Wn3 _n exceeds the set value Wc.

Then, in order to pour the molten metal into the fourth mold 10,
Perform the fourth pouring operation. In this case, after returning the tilt of the container 2 on which the third pouring operation has been performed, the fourth pouring can be performed without performing the sedative waiting step of waiting until the swing of the molten metal in the container 2 is calmed down. Start hot water operation. The current weight Wn4 (Wn4 <Wf3) of the molten metal in the container 2 in the latter half of the fourth pouring operation is determined. This current weight W
The difference (Wf3−Wn4) between n4 and the weight Wf3 of the molten metal in the vessel 2 at the time of the previous draining of the mold 10 poured immediately before the mold 10 is determined. Then, upon reaching the difference (Wf3-Wn4) in the setting value Wc which is set in advance, the control unit 5 a fourth water shortage command Pt ₄ of outputting the tilting pouring device 3. As a result, the tilt pouring device 3 returns the tilt of the container 2. Further, the difference (Wf3−Wn4) is calculated using the fourth mold 10
Is determined to be the weight of the pouring water.

Thereafter, the above-described pouring operation is repeated many times until the molten metal in the container 2 is almost empty, and the pouring operation is performed on a large number of molds 10.

FIG. 5 is an enlarged graph of the weight of the molten metal in the container 2 in the first half and the second half of the pouring operation. As shown in FIG. 5, in the first half of the pouring operation, the fluctuation range of the instantaneous weight value of the molten metal in the container 2 is large.
The reason is that the molten metal in the container 2 is affected by the swing of the molten metal surface. However, in the second half of the pouring operation, the level of the instantaneous weight of the molten metal in the container 2 is considerably small because the level of the molten metal in the container 2 is stabilized. Therefore, as described above, the current weight Wn (Wn1, Wn2, Wn3) is determined based on the instantaneous weight measured in the latter half of the pouring process.
...), The current weight Wn (Wn1, Wn2, Wn) is obtained.
3 ……) accuracy is ensured.

Further, the present inventors have determined that the instantaneous weight values W ₁ , W ₂ , W ₃ , W ₄ , W ₅ ... W _S , W _{S + 1.}
In determining the value, the instantaneous weight value is measured as follows. That is, one wavelength λ and a frequency f [Hz] of the vibration waveform of the weight of the molten metal in the latter half of the pouring operation are obtained, and a cycle Tλ [sec] (Tλ = 1 / f) corresponding to one wavelength λ is obtained. These can be determined to be almost fixed values if the type of the container 2, the material of the molten metal, the number of times of pouring, and the like are the same. In this embodiment, the instantaneous weight value of the molten metal in the container 2 is measured over an integral multiple of the period Tλ [seconds].

The reason is as follows. That is, as for one wavelength of the fluctuation of the instantaneous weight value, as shown in FIG. 5, when the intermediate value of the amplitude at one wavelength is M, the first half Ks and the second half Kf of one cycle have almost opposite phases. It is.
For this reason, if sampling of the instantaneous weight value of the molten metal is performed in the 、 ２ cycle and the 周期 cycle, the phase of the instantaneous weight value is excessively biased, and the accuracy of the current weight of the molten metal cannot be secured. However, if the instantaneous weight value of the molten metal is sampled over one cycle, the data bias in the first half Ks and the data bias in the second half Kf are offset. Therefore, if the average value of the instantaneous weight values measured during the period including both the first half period Ks and the second half period Kf corresponds to the current weight, the accuracy of the current weight of the molten metal in the container 2 is further ensured.

Even if the instantaneous weight value is sampled over an integral multiple of the period, the measurement accuracy is similarly secured. The time of an integral multiple is a period Tλ which is a time required for one wavelength λ.
Means the time obtained by multiplying [sec] by a positive integer, and the period Tλ
It means the time when [sec] is multiplied by 1 time, 2 times, 3 times, 4 times, 5 times ... 10 times, etc. In order to improve the real-time property of the current weight measurement, it is better that the integral multiple is small, and the integral multiple can be increased by one or two.

Therefore, in the present embodiment, in the latter half of the pouring operation,
One wavelength λ of the vibration waveform of the weight of the molten metal and the frequency f [H
z] and a cycle Tλ [second] are obtained, and the cycle Tλ [second] is one time.
In time, the instantaneous weight value W of the molten metal in the container 2₁, W_Two,
W_Three, W_Four, W_Five... W_S, W_{S + 1}I measured a lot of ……
The average value of the instantaneous weight values is used as the current weight Wn (Wn1, Wn).
2, Wn3 ...). This allows the container 2
While ensuring the accuracy of the current weight of the molten metal, the current weight Wn (W
n1, Wn2, Wn3 ...)
Is preserved. In the present embodiment, in the latter half of the pouring operation
The frequency f [Hz] according to is in the range of 1 to 10 [Hz].
You.

As described above, in this embodiment,
The current weight Wn (Wn1, Wn2, Wn) of the molten metal in the vessel 2 during the latter half of the period when the molten metal is being poured into the mold 10.
3...) And obtain the current weight Wn (Wn1, Wn2, W
n3...), and the weight Wf (Wf1, Wf) of the molten metal in the container 2 at the time of the previous draining of the mold 10 poured immediately before.
2, Wf3...). Then, the difference Once (Wf-Wn) is determined reaches the set value, the hot water out command _{Pt (Pt 1, Pt 2,} Pt 3, Pt 4 ...)
Is output to the tilting pouring device 3, and the tilting of the container 2 is returned.

As described above, in the second half of the period when the molten metal is being poured into the mold 10, the swing of the molten metal in the container 2 is reduced, and the molten metal surface is stabilized. The measurement accuracy by the weight detecting means is considerably better than in the first half of the middle of pouring. Therefore, the run-out command Pt (Pt ₁ , Pt ₂ ,
(Pt ₃ , Pt ₄ ...)).

Further, as described above, in the latter half of the pouring, the swing of the molten metal in the container 2 is reduced and stabilized, and the accuracy of the current weight of the molten metal is secured, and the difference (W
f-Wn) can be determined as the pouring weight per one mold 10, and the accuracy of the pouring weight can be secured.
Automatic pouring can be possible.

As described above, the out-of-water instruction Pt (Pt ₁ ,
In this embodiment, which can ensure the accuracy of determination of Pt ₂ , Pt ₃ , Pt ₄ ...), Unlike the prior art, after the tilting of the container 2 having been subjected to the pouring operation is returned, It is not necessary to perform the operation of waiting until the oscillation of the molten metal subsides. That is, it is not necessary to determine the current weight of the molten metal in a state where the surface of the molten metal in the container 2 is calmed down. Therefore, one mold 10
The time required for pouring can be shortened. For this reason, this embodiment is suitable as a pouring control method in a high-speed molding line with a high molding speed.

(Appendix) From the above description, the following technical idea
Can be grasped. A frameless molding line that executes the pouring control method according to each claim.
Pouring method for hot water. High-speed pouring allows high-speed molding of molds
Suitable for frameless molding lines. In each claim, one frameless molding is performed on a frameless molding line.
The mold is formed by a mold device, and one container is formed with respect to the mold.
A pouring control method characterized in that pouring is performed by a container. High speed pouring
Suitable for frameless molding line for high speed molding of molds
You. In each claim, the instantaneous weight value of the molten metal in the container
W₁, W_Two, W_Three, W_Four, W _Five... W_SFind the moving average of ...
Count if each moving average value has reached the set value
Is increased and the count number becomes a predetermined number of times (for example, 20 times, 5 times).
(0 times or 100 times)
Has reached '' and outputs a hot water run command,
If the difference is less than the specified number, it is determined that the difference has reached the set value.
Pouring that is not specified and does not output a run-out command
Control method.

The accuracy of the current weight of the molten metal in the container can be ensured without waiting for the oscillation of the molten metal in the container to completely calm down.

[0068]

As described above, according to the pouring control method according to the present invention, in the latter half of pouring, the swing of the molten metal in the container is reduced and the molten metal surface is stabilized. Therefore, the accuracy of the current weight in the container measured in the latter half of the pouring can be ensured, and the determination accuracy when determining the run-out command can be ensured.

Further, since the current weight of the molten metal in the container, which is the main element for determining the drain command, is measured in the latter half of the pouring, the pouring operation and the weight measurement of the molten metal in the container are performed in parallel. The time required for the entire operation of pouring into one mold can be shortened, which is suitable for high-speed pouring. Therefore, it is suitable for pouring in a high-speed molding line.

[Brief description of the drawings]

FIG. 1 shows a number of molds arranged in series,
It is a top view which shows the pouring tilting apparatus which hold | maintained the container.

FIG. 2 is a side view of the pouring and tilting device shown together with the control device.

FIG. 3 is a graph showing a change state of a tilt angle of a container in one pouring operation.

FIG. 4 is a graph showing changes in instantaneous weight value of molten metal in a container and change in tilt angle of the container when pouring is repeated.

FIG. 5 is a graph showing a change situation of an instantaneous weight value in a first half period and a change situation of an instantaneous weight value in a second half period in a pouring operation.

[Explanation of symbols]

In the figure, 1 is a molding device, 10 is a mold, 2 is a container, 23 is a spout, 3 is a tilting pouring device, 30 is a load cell (melt weight detecting means), 35 is a drive motor, and 5 is a control device.

 ──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Keisuke Yabuhana 1 Aichi Takaoka Corporation, Takaoka Shinmachi, Toyota City, Aichi Prefecture (72) Inventor Yuji Suzuki 1 Takaoka Shinmachi Tenno, Toyota City, Aichi Prefecture Aisin Takaoka Stock In-house (72) Inventor Atsushi Sakano 4-15-10 Daiko, Higashi-ku, Nagoya-shi, Aichi F-term (reference) 4E014 LA04 LA16 LA17

Claims (4)

[Claims] 1. A container having a spout and holding a molten metal, and a tilting pouring device for tilting the container, wherein the tilting pouring device tilts the container so that the molten metal flows from the spout of the container. In the pouring control method of pouring the molten metal into the mold and outputting a run-out command to the tilt pouring device to return the tilt with the completion of pouring into the mold, the weight of the molten metal detecting the weight of the molten metal in the container Using the detection means, upon pouring the molten metal into each of the molds, determine the current weight of the molten metal in the container in at least the latter half of the period of pouring the molten metal from the spout of the container to one of the molds, Find the difference between the current weight and the weight of the molten metal in the container at the time of draining for the other one of the molds poured immediately before the one mold, and when the difference reaches a set value, Issue a run-out command to the tilting pouring device A pouring control method, wherein the tilt of the container is returned by force. 2. The method according to claim 1, wherein after the tilting of the container is returned, the next pouring is started without performing a sedative waiting step of waiting until the swing of the molten metal in the container is calmed down. A pouring control method characterized by the following. 3. A pouring operation according to claim 1, wherein the pouring operation is performed until the molten metal is discharged from a spout of the container.
The tilting speed of the container is large, the tilting speed is large, and the tilting speed of the container is reduced after the molten metal is discharged from the spout of the container, and the tilting speed of the container is small. A pouring control method, comprising: a returning tilting operation. 4. A graph according to claim 1, wherein the horizontal axis represents time and the vertical axis represents the weight of the molten metal in the container, wherein the current weight of the molten metal in the container is Shows a vibration waveform that oscillates with time, measures the instantaneous weight value of the molten metal in the container over an integral multiple of the period of the vibration waveform, and averages the measured instantaneous weight value in the container. A pouring control method, wherein the current weight of the molten metal is regarded as the current weight.