Patent Grant
10537937
The present invention relates to a pouring machine and method to pour molten metal into molds. Specifically, it relates to an automatic pouring machine and method to pour the molten metal into molds of various shapes at suitable pouring rates.
Goods that have been cast have various shapes. To improve productivity, the number of cavities in a mold, namely, multicavity molding, has been increased. Further, various combinations of goods are used. As a result, various patterns for pouring molten metal into molds are required. Thus controlling pouring rates is important.
For example, when the ladle capacity is 500 kg, the pouring weight, the pouring time, and the pouring rate are generally set to be 10 to 50 kg, 4 to 12 seconds, and 1 to 5 kg/second, respectively. When the ladle capacity is 1,000 kg, they are generally set to be 30 to 150 kg, 6 to 15 seconds, and 5 to 10 kg/second. The pouring operations are complicated, but must be accurate. Incidentally, the term “pouring weight” means the weight of the molten metal that has been poured into a mold, and the term “pouring rate” means the flow rate of the molten metal that is being poured from a ladle into a mold.
Conventionally, an automatic pouring method has been known by which molten metal is poured by adjusting the angular velocity so as to tilt a ladle at a predetermined angle by means of feedback control. The predetermined angle is determined so as to follow a pouring pattern that is based on the pouring that is actually carried out by a skilled operator (see Japanese Patent No. 3361369, Japanese Patent Laid-open Publication No. H09-239524, and Published PCT Japanese Translation No. 2013-544188). By the method disclosed by Japanese Patent No. 3361369, the angular velocity to tilt a ladle is corrected by a correction factor that is preliminarily stored so as to maintain the constant pouring rate. By the method disclosed by Japanese Patent Laid-open Publication No. H09-239524, during the final part of the pouring the pouring weight is detected or the level of the surface of melt at a sprue is detected by means of a camera for image processing, so as to stop the pouring. By the method disclosed by Published PCT Japanese Translation No. 2013-544188, pouring patterns for various molds are easily determined by using a pouring weight, a pouring time, and a predetermined pouring pattern. These methods that are disclosed by the prior-art publications are only effective for the particular problems. However, they are not sufficient to automatically control the pouring rate.
By a typical and conventional pouring, molten metal is poured into a sprue for about two seconds by increasing the pouring rate so as not to spill it, so that the gating system is filled with the molten metal. After the molten metal starts to fill the cavity, the pouring rate is adjusted to follow the flow of the molten metal to the cavity while the sprue is watched so that no molten metal spills out. A skilled operator stops the pouring by judging the completion of the pouring based on his or her experience.
However, understanding the progress of the pouring is difficult. If the flow is too little, the temperature of the molten metal decreases or the shapes of molds change, to cause a misrun. On the other hand, if the flow is too great, the molten metal scatters or overflows. Further, estimating the amount of the molten metal that flows into a cavity is difficult. The pouring rate is generally reduced to prevent overflow, so that the pouring time become longer. This operation directly and negatively affects the productivity.
If the operation of the pouring from the beginning to the end of the pouring is controlled only by a deviation between the predetermined pouring pattern and the actual measurements, the delay in the change of the pouring rate causes the molten metal to leak, to overflow, or to have a short run.
If the pouring rate is controlled only by means of the flow of the molten metal into the cavity by using a model based on the relationship between an elapsed time and a flow rate that is based on the flow of the molten metal into the cavity, the operation tends to be carried out so as to ensure safety, so that the pouring time may be lengthened or so that the temperature of the molten metal decreases. Further, no deterioration of the nozzle of the ladle can be dealt with.
To enhance productivity there are strong requirements to shorten the pouring time and to increase the pouring rate. Thus a leak of the molten metal in which the molten metal leaks from the sprue or the molten metal overflows is highly possible. Further, the decrease in the temperature of the molten metal, the adhesion of slag to the nozzle of the ladle, or changes of the shapes of the molds, cause the direction of the flow of the molten metal to change. Thus controlling the flow rate becomes difficult.
The present invention aims to provide a pouring machine and method by which the level of the surface of melt can be constantly maintained from the beginning to the end of the pouring and by which the pouring can be carried out for a proper pouring time without a leak of the molten metal, an overflow, a shrinkage, or a short run, to maintain a necessary and sufficient pouring rate.
In a pouring machine of the first aspect of the present invention, as in
By that configuration, the angle of the tilt of the container can be controlled by using the level of the surface of melt that is detected by means of the surface-of-melt detector and the weight of the molten metal that is detected by means of the weight detector, namely, the weight of the molten metal that has been poured into the mold, to pour the molten metal into the mold. Thus the pouring machine can pour molten metal into a mold for a proper pouring time to maintain constant the level of the surface of melt from the beginning to the end of the pouring and to maintain a necessary and sufficient pouring rate without a leak of the molten metal, an overflow, a shrinkage, or a short run at the end of the pouring.
By a pouring machine of the second aspect of the present invention, as in
By a pouring machine of the third aspect of the present invention, as in
By a pouring machine of the fourth aspect of the present invention, as in
By a pouring machine of the fifth aspect of the present invention, as in
By a pouring machine of the sixth aspect of the present invention, as in
By a pouring machine of the seventh aspect of the present invention, as in
By a pouring machine of the eighth aspect of the present invention, in the pouring machine 1 of the seventh aspect the controller 70 carries out feedforward control by using the value that is obtained by multiplying the angular velocity to tilt the container by the correction function and carries out feedback control by using the level of the surface of melt that is detected by means of the surface-of-melt detector 60 and a weight of the molten metal that is detected by the weight detector 50. By this configuration, the pouring machine can pour molten metal into a mold for a proper pouring time to constantly maintain the level of the surface of melt from the beginning to the end of the pouring and to keep a necessary and sufficient pouring rate without a leak of the molten metal, an overflow, a shrinkage, or a short run at the end of the pouring.
By a pouring machine of the ninth aspect of the present invention, as in
By a pouring machine of the tenth aspect of the present invention, as in
By a pouring machine of the eleventh aspect of the present invention, as in
By a pouring machine of the twelfth aspect of the present invention, as in
A pouring method of the thirteenth aspect of the present invention, as in
By this configuration, since molten metal can be poured into the mold while the angle of the tilt of the container is controlled based on the detected weight and the detected level of the surface of melt, the level of the surface of melt can be maintained at a constant level from the beginning to the end of the pouring, while keeping a necessary and sufficient pouring rate without a leak of the molten metal, an overflow, a shrinkage, or a short run, at the end of the pouring.
By the pouring method of the fourteenth aspect of the present invention, as in
By the pouring method of the fifteenth aspect of the present invention, as in
By the pouring method of the sixteenth aspect of the present invention, as in
By the pouring machine and the pouring method of the present invention, molten metal can be poured into a mold for a proper pouring time to maintain the constant level of the surface of melt from the beginning to the end of the pouring and to maintain a necessary and sufficient pouring rate without a leak of the molten metal, an overflow, a shrinkage, or a short run at the end of the pouring.
The present invention will become more fully understood from the detailed description given below. However, the detailed description and the specific embodiments are only illustrations of the desired embodiments of the present invention, and so are given only for an explanation. Various possible changes and modifications will be apparent to those of ordinary skill in the art on the basis of the detailed description.
The applicant has no intention to dedicate to the public any disclosed embodiment. Among the disclosed changes and modifications, those which may not literally fall within the scope of the present claims constitute, therefore, a part of the present invention in the sense of the doctrine of equivalents.
The use of the articles “a,” “an,” and “the” and similar referents in the specification and claims are to be construed to cover both the singular and the plural form of a noun, unless otherwise indicated herein or clearly contradicted by the context. The use of any and all examples, or exemplary language (e.g., “such as”) provided herein is intended merely to better illuminate the invention, and so does not limit the scope of the invention, unless otherwise stated.
Below, an embodiment of the present invention is discussed with reference to the appended drawings. In the drawings, the same numeral or symbol is used for the elements that correspond to, or are similar to, each other. Thus duplicate descriptions are omitted.
As is obvious from
The mechanism 20 for moving the container back and forth moves on the traveling bogie 10 in the direction perpendicular to a direction that the traveling bogie 10 travels, namely, a direction whereby it comes close to, or moves away from, the mold 100 or the line of molds L. It may be a bogie that travels on a rail that is laid on the traveling bogie 10. It may be a roller conveyor or some other structure.
The vertically moving machine 30 is placed on the mechanism 20 for moving the container back and forth and moves the ladle 2 up and down. In this embodiment it has a pillar 32 that stands on the mechanism 20 for moving the container back and forth. It also has a vertically moving body 34 that surrounds the pillar 32 and moves up and down along the pillar 32. The vertically moving body 34 is suspended by a chain (not shown) and the chain is wound by a driver 36 for moving the body up and down, such as a motor, which is located at the top of the pillar 32. Thus the vertically moving body 34 can be moved up and down. In
The mechanism 40 for tilting the container is supported by the vertically moving machine 30 to be moved up and down. It tilts the ladle 2 so that molten metal is poured from the ladle 2 into a mold 100. A tilting shaft 44 of the mechanism 40 for tilting the container is supported by the vertically moving body 34 so as to be tilted about a horizontal axis. A table 46 for the ladle is supported at one end of the tilting shaft 44 so as to have the ladle 2 be mounted on it. The table 46 for the ladle has a side plate 47 that downwardly extends from the tilting shaft 44 and a bottom plate 48 that horizontally extends from the bottom of the side plate 47, to have the ladle 2 be mounted on it, so that the tilting shaft 44 comes close to the center of gravity of the ladle 2. A driver 42 for the tilting is connected to the other end of the tilting shaft 44 to tilt the tilting shaft. The driver 42 for the tilting may be, for example, a motor with a speed reducer. Incidentally, the tilting shaft 44, i.e., the table 46 for the ladle, may be tilted by means of hydraulic pressure. The type of power for the tilting is not limited.
The load cell 50 detects the weight of the molten metal in the ladle 2. The load cell 50 may be located, for example, at a position to weigh the mechanism 20 for moving the container back and forth. In this case the weight of the molten metal in the ladle 2 is detected by subtracting the weight of the mechanism 20 for moving the container back and forth, of the vertically moving machine 30, of the mechanism 40 for tilting the container, and of the ladle 2, from the weight that is measured by means of the load cell 50. The load cell 50 may be located at a position to weigh the traveling bogie 10, the vertically moving machine 30, the mechanism 40 for tilting the container, or the ladle 2.
The camera 60 takes a picture of the surface of melt at the pouring cup 110 so as to detect the level of the surface of melt at the pouring cup 110 of the mold 100 that is receiving molten metal from the pouring machine 1. It is supported by the arm 62 for the camera that horizontally extends from the upper part of the frame 64, which stands on the traveling bogie 10. The camera 60 is located at a position that is suitable for taking a picture of the surface of melt at the pouring cup 110. The position or angle of the camera 60 is preferably adjusted depending on the relationship between the position of the traveling bogie 10 and that of the pouring cup 110 of the mold 100. The arm 62 for the camera may be extended directly from the controller 70 without the frame 64. The camera 60 may be supported by some other type of structure.
As in
The camera 60, which takes a picture of the surface of melt at the pouring cup 110, is preferably an image sensor, e.g., a CCD or a CMOS. However, the surface-of-melt detector 60 may be an infrared sensor or a laser sensor that detects the level of the surface of melt based on the distance between the surface-of-melt and the surface-of-melt detector 60, not on the area of the surface of melt.
The controller 70 controls the operation of the pouring machine 1. That is, it controls the traveling of the traveling bogie 10, the movement of the mechanism 20 for moving the container back and forth, the vertical movement of the vertically moving machine 30, the tilting of the mechanism 40 for tilting the container, the detection of the weight of the molten metal in the ladle 2 that is measured by means of the load cell 50, the detection of the level of the surface of melt based on the surface of melt, of which a picture is taken by means of the camera 60, and so on. The details of the control by means of the controller is discussed below. The controller 70 is generally placed on the traveling bogie 10, but may be placed at another position or placed directly on the site along the rail R.
Next, the functions of the pouring machine 1 are discussed. The pouring machine 1 receives the ladle 2, which stores molten metal, from a system for transporting molten metal (not shown) within the foundry. The molten metal includes an alloyed metal or an inoculant, depending on the intended use. Generally, after the vertically moving machine 30 has been lowered, the table 46 for the ladle is moved toward the system for transporting molten metal by means of the mechanism 20 for moving the container back and forth so that the ladle 2, which is transported by means of a conveyor for a ladle (not shown), is placed on the table 46 for the ladle. The ladle 2 may be placed on the table 46 for the ladle by means of a crane or the like.
The pouring machine 1 that has the ladle 2 be mounted on it is moved by means of the traveling bogie 10 to the predetermined position to pour molten metal into a mold 100. Then the ladle 2 is moved by means of the mechanism 20 for moving the container back and forth and by means of the vertically moving machine 30, to a position that is suitable for pouring molten metal into a mold. Then the mechanism 40 for tilting the container tilts the ladle 2 to start pouring molten metal into the mold 100.
The ladle 2 tilts about the tilting shaft 44, namely, it rotates to tilt. If the position of the tilting shaft 44 is fixed, the position from which the molten metal flows from the ladle 2 changes, depending on the angle of the tilt. If the position from which the molten metal flows changes, then the position to which the molten metal is poured into the mold 100 changes. Thus the ladle 2 is preferably moved back and forth and up and down by means of the mechanism 20 for moving the container back and forth and by means of the vertically moving machine 30, to constantly maintain the position where the molten metal is poured into the mold 100.
An example of the ladle 2 is shown in
About the pouring from the ladle 2 into the mold 100, the angle T of the tilt of the ladle is controlled from the beginning to the end of the pouring so as to properly maintain the pouring rate. Molten metal is basically poured into a mold based on the pouring pattern that has been preliminarily determined based on the pouring by a skilled operator. By using the flow pattern in this way, an almost perfect pouring rate can be easily ensured. By detecting the weight of the molten metal in the mold 100, the molten metal can be poured at a pouring rate that is nearer the predetermined flow pattern than the pouring that is controlled by only the angle T of the tilt of the mold 100. Since the actual weight of the molten metal that has been poured into the mold 100 is known, any possible overflow at the end of the pouring can be prevented and the pouring can be properly stopped. Further, since it is difficult to predict the flow of the molten metal into the cavity, the level of the surface of melt at the pouring cup 110 must be constantly maintained. Thus an overflow and a shortage of molten metal can be prevented.
With reference to
The central control unit 72 may be divided into an arithmetical section 80 and a storing section 90. The arithmetical section 80 has a means for operating. The storing section 90 has a means for storing data. Here, the means may be hardware, such as a circuit or an element, or a combination of hardware and software. The arithmetical section 80 includes a means 81 for calculating a present position and a velocity of the shaft, a means 82 for calculating a correction to the pouring weight, a means 83 for calculating the area of the sprue, a means 84 for calculating a correction to the level of the surface of melt, a means 85 for calculating an angular velocity to tilt the ladle, an arithmetical element 86 for instructions on the speed and the position of the shaft, and a means 87 for calculating the weight of the molten metal in the ladle.
The storing section 90 includes a means 91 for storing arithmetical data, a means 92 for storing parameters on the elapsed time, a means 93 for storing parameters, a means 94 for storing standard values on the level of the surface of melt, a means 95 for storing correction functions on the angle that the ladle tilts, a means 96 for storing data on the flow patterns, and a means 97 for storing the data on the tare of the ladle.
The means 91 for storing arithmetical data is used for temporarily storing the data to be calculated by the arithmetical section 80. The means 92 for storing parameters on the elapsed time, which is a timer, calculates the elapsed time. That is, it calculates the elapsed time tp from when the molten metal is poured from the ladle 2 into the mold 100. Further, it calculates the time after the molten metal is received by the ladle 2 and the elapsed time after the alloyed metal or the inoculants is added to the molten metal. Especially, the time after the alloyed metal or the inoculants is added is important for judging if any fading (the deterioration of the effect by the alloyed metal or the inoculants when a long time has passed after it is added) has occurred.
The means 93 for storing parameters stores the parameters on the shapes of the molds 100 and the parameters on the shapes of the ladles 2. It outputs the data to the means 82 for calculating any correction to the pouring weight, to the means 84 for calculating a correction to the level of the surface of melt, and to the means 85 for calculating an angular velocity to tilt the ladle.
The means 94 for storing standard values on the level of the surface of melt stores the standard values on the level of the surface of melt at the pouring cup 110. The standard values on the level of the surface of melt vary depending on the mold 100 and the properties of the molten metal. The data on the standard values are output to the means 84 for calculating a correction to the level of the surface of melt.
The means 95 for storing correction functions on the angle that the ladle tilts stores the correction function f(T) on the angle of the tilt. The correction function f(T) on the angle of the tilt represents the relationship between the angle T of the tilt for each kind of ladle and the pouring weight. The means 95 outputs the data to the means 85 for calculating an angular velocity to tilt the ladle.
The means 96 for storing data on the flow patterns stores the data on the flow pattern for each kind of mold and each kind of molten metal. The data on the flow pattern, such as the pouring weight, i.e., the weight of the molten metal in the ladle 2, at every moment of time, and the angular velocity to tilt the ladle, is stored. It outputs the data to the means 82 for calculating a correction to the pouring weight and the means 85 for calculating an angular velocity to tilt the ladle.
The means 97 for storing the data on the tare of the ladle stores the data on the weights of devices and equipment other than the molten metal, which weights are included in the weights that are detected by the load cell 50. The devices and equipment other than the molten metal include the ladle 2, the mechanism 20 for moving the container back and forth, the vertically moving machine 30, the mechanism 40 for tilting the container, and so on. It outputs the data to the means 87 for calculating the weight of the molten metal in the ladle.
The means 81 for calculating a present position and a velocity of the shaft calculates the position and velocity of the shaft of each device. It may calculate it based on the data on the movement of the ladle 2 that is measured by the mechanism 20 for moving the container back and forth, by the vertically moving machine 30, and by the mechanism 40 for tilting the container. Alternatively, it may calculate it based on the instructions on operations that are sent from the arithmetical element 86 for instructions on the speed and the position of the shaft, which element is discussed below, to the mechanism 20 for moving the container back and forth, to the vertically moving machine 30, or to the mechanism 40 for tilting the container. The calculated value, namely, the position and the angle of the tilt of the ladle 2 at the time, is output to the means 85 for calculating an angular velocity to tilt the ladle.
The means 82 for calculating a correction to the pouring weight calculates the difference between the weight of the molten metal in the ladle 2 that is detected by the means 87 for calculating the weight of the molten metal in the ladle, which means is discussed below, and the weight of the molten metal by the flow pattern that is sent by the means 96 for storing data on the flow patterns. Then it calculates the correction to the weight of the molten metal that is to be poured from the ladle 2 into the mold 100 based on the parameters of the shape of the ladle 2 and so on that are sent by the means 93 for storing parameters. It outputs the correction to the means 85 for calculating an angular velocity to tilt the ladle.
The means 83 for calculating the area of the sprue calculates the area of the sprue based on the image data that are sent by the arithmetic unit 76 for image processing to output the area to the means 84 for calculating a correction to the level of the surface of melt. The means 84 for calculating a correction to the level of the surface of melt calculates the level of the surface of melt based on the area of the sprue and the parameters on the shape of the pouring cup 110 that are sent by the means 93 for storing parameters. Then it calculates the correction to the level of the surface of melt based on the standard value that is sent by the means 94 for storing standard values on the level of the surface of melt to output the result to the means 85 for calculating an angular velocity to tilt the ladle.
The means 85 for calculating an angular velocity to tilt the ladle calculates an angular velocity to tilt the ladle 2 based on the position and the angle of the tilt of the ladle 2 at the time that they are sent by the means 81 for calculating a present position and a velocity of the shaft, the correction to the pouring weight that is sent by the means 82 for calculating a correction to the pouring weight, and the correction to the level of the surface of melt that is sent by the means 84 for calculating a correction to the level of the surface of melt. It outputs the calculated angular velocity to the arithmetical element 86 for instructions on the speed and the position of the shaft. To calculate the angular velocity to tilt the ladle 2, the parameters on the shape of the ladle 2, etc., that are sent by the means 93 for storing parameters, the correction function f(T) on the angle of the tilt that is sent by the means 95 for storing correction functions on the angle that the ladle tilts, and the angular velocity to tilt the container of the flow pattern that matches the mold 100, which flow pattern is sent by the means 96 for storing data on the flow patterns, are used. Incidentally, the calculations of the correction function f(T) on the angle of the tilt and the angular velocity to tilt the ladle 2 are discussed below.
The arithmetical element 86 for instructions on the speed and the position of the shaft calculates the instructions on operations to be sent to the mechanism 20 for moving the container back and forth, the vertically moving machine 30, and the mechanism 40 for tilting the container, based on the angular velocity to tilt the ladle 2 that is sent by the means 85 for calculating an angular velocity to tilt the ladle. It outputs the instructions to each device and to the means 81 for calculating a present position and a velocity of the shaft, via the amplifier 74 for a driver for the shaft.
The means 87 for calculating the weight of the molten metal in the ladle calculates the weight of the molten metal in the ladle based on the weights that are detected by the load cells 50, the data on which weights are sent by the amplifier 78 for the load cell, the data on the weight of the ladle 2 that is sent by the means 97 for storing the data the tare of the ladle, and the data on the weights that are sent by the mechanism 20 for moving the container back and forth, by the vertically moving machine 30, and by the mechanism 40 for tilting the container. It outputs the calculated weight to the means 82 for calculating a correction to the pouring weight.
With reference to
In the initial pouring the molten metal is poured into the mold for a short period, i.e., about two seconds, by increasing the flow rate, but not enough to spill the molten metal from the pouring cup, to fill the pouring cup 110, the sprue, and a runner (collectively called the gating system) with the molten metal. In doing so the angle T of the tilt of the ladle 2 is determined based on the flow pattern. That is, the means 85 for calculating an angular velocity to tilt the ladle calculates by Equation (1) an angular velocity VTp to tilt the container by the instructions at a time tp, which angular velocity is suitable for the ladle 2. That calculation is based on the data VTobj (tp) on the angular velocity necessary to tilt the container at the elapsed time tp that is stored by the means 96 for storing data on the flow patterns.
VTp=f(T)·VTobj(tp) (1)
Where f(T): the correction factor for the angular velocity to tilt the container,
The arithmetical element 86 for instructions on the speed and the position of the shaft calculates the displacement of the mechanism 20 for moving the container back and forth, of the vertically moving machine 30, and of the mechanism 40 for tilting the container, based on the angular velocity VTp necessary to tilt the container as specified by the instructions. It outputs the displacement to each device via the amplifier 74 for a driver for the shaft. Since each device 20, 30, 40 moves under the instructions that are sent by the arithmetical element 86 for instructions on the speed and the position of the shaft, the mechanism 40 for tilting the container tilts the ladle 2 by the angular velocity to tilt the container. Further, the tilting shaft 44 moves along an arc about the center O for the movement. That is, the controller 70 carries out feedforward control by using the angular velocity VTp to tilt the container as specified by the instructions. Namely, the velocity VTp is a value obtained by multiplying the angular velocity VTobj(tp) to tilt the container of the flow pattern by the correction factor f(T) for the angular velocity to tilt the container.
When the gating system is filled with the molten metal, the molten metal starts to fill the cavity. During the step of filling the cavity with the molten metal, first the ladle 2 is tilted based on the flow pattern. Up to this operation, the control is the same as that for the above-mentioned control in the initial pouring.
While the molten metal is being poured from the ladle 2 into the mold 100, the weight of the devices that include the ladle 2 is detected by means of the load cell 50. The means 87 for calculating the weight of the molten metal in the ladle continuously measures the weight of the molten metal in the ladle. Incidentally, the meaning of the wording “the load cell 50 detects the weight of the molten metal in the ladle 2” may include the operation where the means 87 for calculating the weight of the molten metal in the ladle calculates the weight of the molten metal in the ladle 2. The means 82 for calculating a correction to the pouring weight calculates the difference between the detected weight of the molten metal in the ladle 2 and the weight of the molten metal of the flow pattern, so as to output the correction to the pouring weight to the means 85 for calculating an angular velocity to tilt the ladle. The means 85 for calculating an angular velocity to tilt the ladle calculates the correction VTw to the angular velocity to tilt the ladle by using Equation (2), based on the correction to the pouring weight and by using the correction factor cg for the pouring weight that is sent by the means 93 for storing parameters. Incidentally, the calculation within the mark “{ }” in Equation (2) is carried out by the means 82 for calculating a correction to the pouring weight.
VTm=cg·{gobj(tp)·g(tp)} (2)
Where cg: the correction factor for the pouring weight that introduces the angular velocity to tilt the ladle based on the correction to the pouring weight
The correction VTw to the angular velocity to tilt the ladle is output to the arithmetical element 86 for instructions on the speed and the position of the shaft. The arithmetical element 86 for instructions on the speed and the position of the shaft outputs the respective corrections to the displacement to the mechanism 20 for moving the container back and forth, to the vertically moving machine 30, and to the mechanism 40 for tilting the container, to correct the angle T of the tilt of the ladle 2. That is, the controller 70 carries out feedback control by using the weight of the molten metal in the ladle 2 that is detected by means of the load cell 50.
While the molten metal is being poured from the ladle 2 into the mold 100, the camera 60 continuously takes the picture of the surface of melt at the pouring cup 110 of the mold 100. The data that is taken by the camera 60 is converted to the image data by means of the arithmetic unit 76 for image processing. The means 83 for calculating the area of the sprue calculates the area of the sprue. Then the means 84 for calculating a correction to the level of the surface of melt calculates the level of the surface of melt based on that area of the sprue and the parameters that are sent by the means 93 for storing parameters. Incidentally, the data on the surface of melt that are taken by the camera 60 are processed by the arithmetic unit 76 for image processing and the means 84 for calculating a correction to the level of the surface of melt to obtain the level of the surface of melt. The meaning of the wording “the camera 60 detects the level of the surface of melt at the pouring cup 110” may include the level of the surface of melt being calculated in the above-mentioned way. The means 84 for calculating a correction to the level of the surface of melt calculates the correction to the level of the surface of melt based on the difference between the calculated level of the surface of melt and the standard value that is sent by the means 94 for storing standard values on the level of the surface of melt. The means 85 for calculating an angular velocity to tilt the ladle calculates the correction VTs to the angular velocity to tilt the container by using Equation (3) based on the correction to the level of the surface of melt and the correction factor cl for the level of the surface of melt that is sent by the means 93 for storing parameters. The calculation within the mark “{ }” in Equation (3) is carried out by the means 84 for calculating a correction to the level of the surface of melt.
VTs=Cl·{sobj−s} (3)
where cl: the correction factor for the level of the surface of melt that introduces the angular velocity to tilt the ladle based on the correction to the level of the surface of melt
The correction VTs to the angular velocity to tilt the ladle is output to the arithmetical element 86 for instructions on the speed and the position of the shaft. The arithmetical element 86 for instructions on the speed and the position of the shaft sends the respective correction values for the displacement to the mechanism 20 for moving the container back and forth, the vertically moving machine 30, and the mechanism 40 for tilting the container, to correct the angle T of the tilt of the ladle 2. That is, the controller 70 carries out feedback control by using the level of the surface of melt at the pouring cup 110 of the mold 100, which level is detected by the camera 60.
When the end of the pouring is approaching, the time to stop the pouring is determined based on the weight of the molten metal in the ladle 2 that is detected by means of the load cell 50. The angle of the tilt of the ladle is returned to 0 (zero) based on the data on the angular velocity to tilt the container when the pouring, in line with the flow pattern, stops. Generally it is returned at the maximum velocity. In this case only the mechanism 40 for tilting the container may operate, and so the ladle 2 is not necessarily moved up and down and back and forth, so that the tilting shaft 44 moves along an arc about the center O for the movement.
The pouring rate from the ladle 2 into the mold 100 is adjusted by controlling the angle T of the tilt of the ladle 2 based on the flow pattern. At the same time the pouring rate from the ladle 2 into the mold 100 is adjusted by correcting the angle T of the tilt based on the weight of the molten metal in the ladle 2 that is detected by means of the load cell 50 and the level of the surface of melt at the pouring cup 110 of the mold 100 that is detected by means of the camera 60. Thus the correction shown as crossed-out areas in
In the above discussion the controller 70 carries out the calculations by the respective specific means. However, it does so by some other means. The configuration of the controller 70 is not limited.
The controller 70 may carry out other controls, such as the measurement of the time after the molten metal is received by the ladle 2, the measurement of the time after an alloyed metal or an inoculants is added, the control of the movement of the pouring machine 1, the detection of any abnormality of the voltage received, or the detection and generation of the alarm that ensures safe operations.
In the first mechanism 130 for tilting the container a pillar 131 and a first driver 132 for the tilting are fixed to the mechanism 20 for moving the container back and forth. A first tilting shaft 136 is rotatably supported at the top of the pillar 131. A first frame 134 for tilting is fixed to the first tilting shaft 136. A first sector gear 138 is fixed to the first frame 134 for tilting and is engaged with a first pinion 139 of the first driver 132 for the tilting. That is, when the first pinion 139 is rotated by means of the first driver 132 for the tilting, the first sector gear 138 and the first frame 134 for tilting are tilted about the first tilting shaft 136.
In the second mechanism 140 for tilting the container, a supporting plate 141 is supported so as not to move by means of the first tilting shaft 136 of the first mechanism 130 for tilting the container. Namely, the supporting plate 141 tilts together with the first tilting shaft 136. A second tilting shaft 146 is supported so as to be tilted at a position in the supporting plate 141 that is near the lip for pouring 6 of the ladle 2. A second frame 144 for tilting is fixed to the second tilting shaft 146. A second sector gear 148 is fixed to the second frame 144 for tilting at the side that is opposite the second tilting shaft 146 and is engaged with the second pinion 149 of the second driver 142 for the tilting. Namely, when the second pinion 149 is rotated by means of the second driver 142 for the tilting, the second sector gear 148 and the second frame 144 for tilting are tilted about the second tilting shaft 146. Incidentally, the second driver 142 for the tilting is supported by means of the first frame 134 for tilting.
The ladle 2 is supported by the second mechanism 140 for tilting the container. If the first mechanism 130 for tilting the container tilts, then the supporting plate 141 also tilts, so that the second tilting shaft 146 moves upside down. The second mechanism 140 for tilting the container tilts about the second tilting shaft 146. Thus the first mechanism 130 for tilting the container can move the ladle 2 up and down.
In the pouring machine 101 a frame 164 is provided to the mechanism 20 for moving the container back and forth. An arm 162 for the camera horizontally extends from the frame 164 to hold the camera 60. The frame 164 may be provided to the pillar 131.
In the pouring machine 101 the load cell 50 is placed between the traveling bogie 10 and the mechanism 20 for moving the container back and forth. The load cell 50 may be placed at another place if it detects the weight of the ladle 2. The controller 70 is provided like the pouring machine 1, although it is shown in
By the pouring machine 101 the ladle 2 can be moved by means of the traveling bogie 10 to any position along the line of molds L. It can come close to, and move away from, the molds 100 by means of the mechanism 20 for moving the container back and forth. It can tilt about the first tilting shaft 136 by means of the first mechanism 130 for tilting the container and about the second tilting shaft 146 by means of the second mechanism 140 for tilting the container. Thus, since it is moved by means of the mechanism 20 for moving the container back and forth and tilted about the first tilting shaft 136 and about the second tilting shaft 146, the molten metal can be poured from the ladle 2 into the mold 100 to constantly maintain the position to be poured. The second tilting shaft 140 can be used as the center O for the movement of the pouring machine 1. The molten metal can be poured into the mold while the level of the surface of melt at the pouring cup 110 is detected by means of the camera 60 and while the weight of the molten metal in the ladle 2 is detected by means of the load cell 50.
The position of the camera 60 is preferably adjusted by means of the arm 162 for the camera depending on the positional relationship between the pouring machine 101 and the pouring cup 110. For example, the frame 164 may be configured to move depending on the tilting of the first mechanism 130 for tilting the container.
In the above discussion the molten metal is poured from the ladle 2 into the mold 100. However, the container 2 of the present invention may be a melting furnace or the like. For example, when cast steel is used for casting, the molten metal is preferably poured from the melting furnace into the mold without transferring the molten metal to the ladle, so that the metal is maintained at a high temperature. In this case, since the melting furnace is very heavy, the container 2, namely, the melting furnace, is not moved up and down, but the mold 100 is moved up and down to constantly maintain the position to pour the molten metal. That is, the pouring machine 1 may not be equipped with the vertically moving machine 30, but instead it may be equipped with a vertically moving machine (not shown) to move the mold 100 up and down.
Below, the main reference numerals and symbols that are used in the detailed description and drawings are listed.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/JP2015/056615 | 3/6/2015 | WO | 00 |
| Publishing Document | Publishing Date | Country | Kind |
|---|---|---|---|
| WO2016/142983 | 9/15/2016 | WO | A |
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| Extended European Search Report for corresponding EP Application No. 15884481.1 dated Jul. 9, 2018. |
| International Search Report issued by the Japan Patent Office in International Application No. PCT/JP2015/056615, dated May 26, 2015 (2 pages). |
| Number | Date | Country | |
|---|---|---|---|
| 20180029116 A1 | Feb 2018 | US |
