System for determining the set temperature of molten metal

Abstract

To provide a technique which can determine a molten metal set temperature in consideration of energy efficiency.SOLUTION: A system for determining a molten metal set temperature in a molten metal pouring facility comprises: a temperature sensor for detecting a molten metal temperature at a nozzle tip of a ladle during molten metal pouring treatment; and a control unit for acquiring temperature transitions obtained by plotting the molten metal temperature detected with the temperature sensor per frame. The control unit denotes the temperature transitions which fall within a temperature range determined by an upper limit temperature and a pre-determined lower limit temperature as the optimum temperature transitions, determines the upper limit temperature so that a ratio between the number of the acquired plural temperature transitions and the number of the optimum temperature transitions included in the plural temperature transitions reaches a prescribed ratio, and determines a temperature obtained by adding a reduced temperature being a temperature which reduces upon conveying treatment and the determined upper limit temperature as a set temperature.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present disclosure relates to a system for determining a set temperature of molten metal. [Background Art]

[0002] Patent Document 1 discloses a pouring facility. The pouring facility comprises a melting furnace that produces molten metal at a set temperature. A ladle receives the molten metal produced by the melting furnace. The ladle containing the molten metal is conveyed to a pouring machine. The pouring machine sequentially pours the molten metal in the ladle into a plurality of molds. The pouring facility repeatedly performs a series of processes from receiving the molten metal to pouring the molten metal. [Prior Art Documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent No. 6472899 [Summary of the Invention] [Problem to be Solved by the Invention]

[0004] By the way, when the temperature of the molten metal during pouring is low, defects such as misruns may occur. In order to avoid defects, in the pouring facility described in Patent Document 1, there is a risk that the set temperature of the molten metal in the melting furnace is set higher than necessary. The present disclosure provides a system capable of determining the set temperature of molten metal in consideration of energy efficiency. [Means for Solving the Problem]

[0005] A system relating to one aspect of this disclosure determines the set temperature of molten metal in a pouring facility. The pouring facility repeats a series of processes including a receiving process in which molten metal produced in a melting furnace that produces molten metal at the set temperature is received into a ladle, a transport process in which the ladle is transported to a pouring machine, and a pouring process in which the molten metal in the ladle is sequentially poured into multiple molds by the pouring machine. The system has a temperature sensor and a control unit. The temperature sensor detects the temperature of the molten metal at the tip of the ladle nozzle during the pouring process. For each pouring process, the control unit acquires the temperature transitions plotted by the temperature sensor for each frame. The control unit defines the temperature transitions that fall within a temperature range determined by an upper limit temperature and a predetermined lower limit temperature as the optimal temperature transitions, determines the upper limit temperature so that the ratio of the number of acquired temperature transitions to the number of optimal temperature transitions included in the multiple temperature transitions is a predetermined ratio, and determines the set temperature as the sum of the decreased temperature, which is the temperature that decreases during the transport process, and the determined upper limit temperature. [Effects of the Invention]

[0006] According to this disclosure, a technology is provided that allows for determining the set temperature of the molten metal while taking energy efficiency into consideration. [Brief explanation of the drawing]

[0007] [Figure 1] This is a plan view showing a part of the casting equipment targeted by the temperature setting determination system according to an exemplary embodiment. [Figure 2] This is a side view showing an example of a hot water receiving cart. [Figure 3] This is a front view showing an example of a pouring machine. [Figure 4] This is a top view showing an example of a pouring machine. [Figure 5] This is a block diagram showing an example of a set temperature determination system according to an exemplary embodiment. [Figure 6] This graph shows an example of the changes in casting temperature for each ladle. [Figure 7] This graph shows the relationship between the cumulative number of castings and the casting temperature. [Figure 8]This flowchart shows an example of the operation of a set temperature determination system according to an exemplary embodiment. [Figure 9] This flowchart shows an example of the operation of a set temperature determination system according to an exemplary embodiment. [Figure 10] This flowchart shows an example of the operation of a set temperature determination system according to an exemplary embodiment. [Modes for carrying out the invention]

[0008] [Summary of the embodiments of this disclosure] First, an overview of the embodiments of this disclosure will be provided.

[0009] (Clause 1) A system relating to one aspect of the present disclosure determines the set temperature of molten metal in a pouring equipment. The pouring equipment repeats a series of processes including a receiving process in which molten metal produced in a melting furnace that produces molten metal at the set temperature is received into a ladle, a transport process in which the ladle is transported to a pouring machine, and a pouring process in which the molten metal in the ladle is sequentially poured into multiple molds by the pouring machine. The system has a temperature sensor and a control unit. The temperature sensor detects the temperature of the molten metal at the tip of the ladle nozzle during the pouring process. For each pouring process, the control unit acquires the temperature transitions plotted by the temperature sensor for each frame. The control unit defines the temperature transitions that fall within a temperature range determined by an upper limit temperature and a predetermined lower limit temperature as the optimal temperature transitions, determines the upper limit temperature such that the ratio of the number of acquired temperature transitions to the number of optimal temperature transitions included in the multiple temperature transitions is a predetermined ratio, and determines the set temperature as the sum of the decreased temperature, which is the temperature that decreases during the transport process, and the determined upper limit temperature.

[0010] In this system, a pouring process is performed in which molten metal is poured sequentially from a ladle into multiple molds. When the ladle is empty, the next pouring process is performed in which molten metal is poured sequentially from the next ladle into multiple molds. After each pouring process, the temperature progression is obtained by plotting the molten metal temperature detected by a temperature sensor for each frame. The upper limit temperature is determined such that the ratio of the number of temperature progressions obtained to the number of optimal temperature progressions included in those progressions is a predetermined ratio. The optimal temperature progression is a temperature progression that falls within the temperature range determined by the upper limit temperature and a predetermined lower limit temperature. The set temperature is determined by adding the temperature decrease temperature (the temperature that decreases during the transport process) and the determined upper limit temperature.

[0011] In this way, the set temperature is determined, and this determined set temperature can be adopted as the set temperature for the next molten metal melt. The upper limit temperature used to determine the set temperature is determined such that the ratio of the number of temperature transitions to the number of optimal temperature transitions included in those transitions is a predetermined ratio (for example, 60-80%). Therefore, this system can avoid setting the set temperature of the molten metal in the melting furnace higher than necessary. Thus, this system can determine the set temperature of the molten metal while considering energy efficiency.

[0012] (Clause 2) In the system described in Clause 1, the control unit may select from the temperature transitions of the pouring process a pouring process using the same model as the model used in the pouring process corresponding to the acquired temperature transition, determine an upper limit temperature so that a predetermined proportion of the temperature transitions of the selected pouring processes become the optimal temperature transition, and determine the temperature obtained by adding the decrease in temperature and the determined upper limit temperature as the set temperature corresponding to the model. In this case, the system can determine the optimal set temperature of the molten metal for each model.

[0013] (Clause 3) In the system described in Clause 1 or 2, the control unit may re-determine the upper limit temperature if the temperature progression includes a molten metal temperature lower than the lower limit temperature. In this case, the system can re-determine the set temperature by reviewing the upper limit temperature when a situation arises that is likely to cause a malfunction, while avoiding setting the set temperature of the molten metal in the melting furnace higher than necessary.

[0014] (Clause 4) The system according to any one of Clauses 1 to 3 may further comprise a display device that displays information related to a melting furnace, and the control unit may cause the display device to display information related to a difference when the difference between a molten metal temperature of a first batch included in the obtained temperature transition and an upper limit temperature is not within a preset range. In this case, the system can notify, for example, an operator of the melting furnace via the display device that there has been a change in the temperature drop.

[0015] (Clause 5) In the system according to any one of Clauses 1 to 4, the system may further comprise a display device that displays information related to a melting furnace, and the control unit may cause the display device to display the molten metal temperature of the last batch included in the obtained temperature transition. The temperature of the molten metal poured into the last batch in a pouring process is the lowest in said pouring process. By causing the display device to display the lowest temperature in the pouring process, an operator can monitor the lowest temperature and determine whether a situation where a malfunction is likely to occur has arisen.

[0016] (Clause 6) A system according to another aspect of the present disclosure determines a set temperature of molten metal in a pouring facility. The pouring facility repeats a series of processes including: a molten metal receiving process of receiving, into a ladle, molten metal produced by a melting furnace that produces molten metal at a set temperature; a conveying process of conveying the ladle to a pouring machine; and a pouring process of pouring the molten metal in the ladle sequentially into a plurality of molds by the pouring machine. The system comprises a temperature sensor and a control unit. The temperature sensor detects the temperature of molten metal at a nozzle tip of the ladle during the pouring process. The control unit obtains, for each pouring process, a temperature transition obtained by plotting the molten metal temperature detected by the temperature sensor for each batch, and determines the set temperature. The set temperature determined by the control unit satisfies a relationship where the set temperature is a temperature obtained by adding an upper limit temperature and a temperature drop, wherein the upper limit temperature is determined such that when a temperature transition falling within a temperature range defined by the upper limit temperature and a predetermined lower limit temperature is defined as an optimal temperature transition, a ratio of the number of optimal temperature transitions included in a plurality of obtained temperature transitions to the total number of the plurality of obtained temperature transitions reaches a predetermined ratio, and the temperature drop is a temperature that decreases during the conveying process. This system achieves the same effect as the system described in Clause 1.

[0017] [Example of Embodiment of the Present Disclosure] Hereinafter, exemplary embodiments of the present disclosure will be described with reference to the drawings. In the following description, identical or corresponding elements are denoted by identical reference signs, and repeated descriptions are not repeated.

[0018] [Outline of Casting Equipment] It is a plan view showing a part of casting equipment targeted by a set temperature determination system according to an exemplary embodiment. The casting equipment 100 shown in FIG. 1 discharges a portion of the base molten metal obtained in a melting furnace into a ladle, conveys the ladle storing the molten metal to a pouring machine, and pours the molten metal in the conveyed ladle into a mold using the pouring machine. As shown in FIG. 1, the casting equipment 100 includes a melting furnace 2 as an example. The melting furnace 2 melts a melting material by heat to obtain base molten metal. The number of the melting furnace 2 may be one or may be plural. In the example shown in FIG. 1, two melting furnaces 2 are arranged in parallel. A corresponding melting material feeding device is arranged in parallel with each melting furnace 2, and the melting material is fed into the furnace by the melting material feeding device. The melting furnace 2 can obtain an amount of base molten metal at one time that is sufficient to discharge molten metal to a receiving ladle described below for multiple times.

[0019] The melting furnace 2 produces base molten metal at a set temperature. The set temperature is the target temperature of the base molten metal. The set temperature may be set for each model, for example. A worker refers to information related to the set temperature displayed on a display device 50 provided near the melting furnace 2, and controls the output of the melting furnace 2 to adjust the temperature of the base molten metal to reach the set temperature. The set temperature determination system according to an exemplary embodiment is a system that determines the set temperature.

[0020] The molten metal obtained from the melting furnace 2 is poured into the processing ladle LD1. The processing ladle LD1 cures the molten metal and transmits it to the next process. The processing ladle LD1 is placed on the receiving trolley 4 and moves along the receiving trolley rail R1. Before receiving the molten metal, the receiving trolley 4 moves to the position of the primary inoculation device 3 to adjust the composition of the base molten metal, and the material to adjust the composition of the base molten metal is added to the processing ladle LD1 by the primary inoculation device 3. After that, the receiving trolley 4 moves to the receiving position, and the molten metal is poured from the melting furnace 2 into the processing ladle LD1. The receiving trolley 4 moves to the emptying position, and the molten metal in the processing ladle LD1 is transferred to the pouring ladle LD2 (an example of the receiving process). Emptying means transferring the molten metal from one ladle to another ladle. When transferring the molten metal from the processing ladle LD1 to the pouring ladle LD2, additive materials are added to the pouring ladle LD2 by the secondary inoculation device 5, and the composition of the molten metal is adjusted.

[0021] The pouring ladle LD2 is placed on the transport trolley 6 and transported along the transport trolley rail R2. In addition to the empty replacement position described above, the transport trolley 6 can also stop at the ladle replacement position where the pouring ladle LD2 is transported to the pouring machine 10.

[0022] The pouring ladle LD2 is transported along the transport trolley rail R2 and arrives at the pouring equipment (an example of transport process). At the pouring equipment, molten metal is poured into the mold MD. The pouring ladle LD2 (actual ladle) containing molten metal is transferred from the transport trolley 6 to the ladle exchange device 9 in front of the pouring machine 10 (ladle exchange position). At the ladle exchange device 9, the actual ladle is exchanged for the empty pouring ladle LD2 (empty ladle) that has been used for pouring. For example, the exchange between the actual ladle and the empty ladle is achieved by the pouring machine 10 sliding. For example, the empty ladle is transferred from the pouring machine 10 to the roller conveyor 8 by the pouring machine 10 sliding in front of the roller conveyor 8. The actual ladle is transferred from the roller conveyor 7 to the pouring machine 10 by the pouring machine 10 sliding in front of the roller conveyor 7.

[0023] The pouring machine 10 pours the molten metal stored in the pouring ladle LD2 into the mold MD (an example of the pouring process). The pouring machine 10 is located to the side of the pouring zone 14. In the pouring zone 14, a mold transport device transports multiple molds MD, which have been formed by a molding machine (not shown), in a row, one mold at a time. In the pouring zone 14, the pouring machine 10 sequentially pours the molten metal from the pouring ladle LD2 into the transported molds MD.

[0024] In the pouring zone 14, rails for the molds are laid, and at both ends of the rails are a set of mold feeding devices 11 (pusher and cushion), which are mold transport devices. The pusher that makes up the mold feeding device 11 has the function of pushing out the mold MD, and the cushion that makes up the mold feeding device 11 has the function of receiving the pushed-out mold MD. The pusher and cushion allow the mold MD to be fed out without any gaps. The mold feeding device 11 feeds out the mold MD one mold at a time. In Figure 1, only the mold feeding device (cushion) at the front end of the rail is shown, and the mold feeding device (pusher) located at the rear end of the rail is not shown.

[0025] A pouring rail R3 for the pouring machine is laid in the pouring zone 14. The pouring rail R3 is laid along the rail for the mold. The pouring machine 10 has a pouring ladle LD2 on it and is movable along the pouring rail R3. The pouring machine 10 moves to any position on the pouring rail R3, tilts the pouring ladle LD2, and pours molten metal into the mold MD.

[0026] When the mold MD reaches the front end of the rail in the pouring zone 14, it is transported to the adjacent cooling zone 15 by a traverser 13. In the cooling zone, the mold MD is transported to a mold dismantling device (not shown) while the product after pouring is cooled inside the mold MD. In the cooling zone 15, rails for the mold MD are laid, and a set of mold feeding devices 12 (pusher and cushion) are placed at both ends of the rail, similar to the pouring zone 14. In Figure 1, only the mold feeding device (pusher) at the rear end of the rail is shown, and the mold feeding device (cushion) located at the front end of the rail is not shown. The operation of the mold feeding device 12 is the same as the operation of the mold feeding device 11. The mold feeding device 12 transports the mold MD in the cooling zone 15 in the opposite direction to the transport direction of the mold MD in the pouring zone 14. After the molten metal is poured, the mold MD is cooled slowly on rails, and the molten metal solidifies into a casting before reaching the mold removal device.

[0027] In the casting equipment 100, a series of processes are repeatedly performed, including a receiving process in which the molten metal produced in the melting furnace 2, which produces molten metal at a set temperature, is received into the pouring ladle LD2; a transport process in which the pouring ladle LD2 is transported to the pouring machine 10; and a pouring process in which the pouring machine 10 sequentially pours the molten metal in the pouring ladle LD2 into multiple molds MD.

[0028] [Details of the hot water receiving cart] Figure 2 is a side view showing an example of a receiving trolley. As shown in Figure 2, the receiving trolley 4 carries the processing ladle LD1 and travels along the receiving trolley rail R1. This allows the receiving trolley 4 to move between the material input position by the primary inoculation device 3, the receiving position by the melting furnace 2, and the emptying position from the processing ladle LD1 to the pouring ladle LD2. The receiving trolley 4 is equipped with an emptying mechanism 41 that supports the processing ladle LD1 in a tiltable manner. The emptying mechanism 41 tilts the processing ladle LD1 around a tilting axis H that extends in the X direction in the figure. Furthermore, the receiving trolley 4 is equipped with a lifting mechanism 42 that supports the processing ladle LD1 in a vertically movable manner. This allows the processing ladle LD1 to be emptyed from a predetermined height.

[0029] The molten metal receiving cart 4 has a non-contact first temperature sensor 43 that measures the temperature of the received molten metal (receiving temperature). The first temperature sensor 43 calculates the temperature of the molten metal using, for example, the amount of bicolor infrared radiation detected by the sensor head of a bicolor thermometer.

[0030] The hot water receiving trolley 4 has a first load cell 44 that detects the weight of the processing ladle LD1. The first load cell 44 is provided, for example, on a member that supports the processing ladle LD1.

[0031] [Details of the pouring machine] Figure 3 is a front view showing an example of a pouring machine. Figure 4 is a top view showing an example of a pouring machine. As shown in Figures 3 and 4, the pouring machine 10 places the pouring ladle LD2 on it and travels along the pouring rail R3. This allows the pouring ladle LD2 to move along the mold row. Furthermore, the pouring machine 10 supports the pouring ladle LD2 so that it can tilt. The pouring machine 10 tilts the pouring ladle LD2 about a tilting axis K that extends in the Y direction in the figure. Furthermore, the pouring machine 10 supports the pouring ladle LD2 so that it can be raised and lowered and moved in the front-rear direction. This allows the pouring ladle LD2 to pour from a predetermined position and height.

[0032] The pouring machine 10 has a non-contact second temperature sensor 20 (an example of a temperature sensor) that measures the temperature of the molten metal to be poured. The second temperature sensor 20 calculates the temperature of the molten metal using the amount of bicolor infrared radiation detected by, for example, the sensor head of a bicolor thermometer. The measurement position of the second temperature sensor 20 is set to be the nozzle tip 21, which is the outlet of the pouring ladle LD2. This allows the second temperature sensor 20 to measure the temperature of the pouring flow.

[0033] The pouring machine 10 has a second load cell 22 for detecting the weight of the pouring ladle LD2. The second load cell 22 is provided, for example, on a member that supports the pouring ladle LD2.

[0034] [Overview of the temperature setting determination system] Figure 5 is a block diagram showing an example of a set temperature determination system according to an exemplary embodiment. The set temperature determination system 1 shown in Figure 5 comprises a second temperature sensor 20 and a control unit 30. As described above, the second temperature sensor 20 is a device that detects the molten metal temperature at the nozzle tip 21 of the pouring ladle LD2 during the pouring process. The second temperature sensor 20 outputs the detection result to the control unit 30.

[0035] The control unit 30 is a controller that provides overall control over the set temperature determination system 1. The control unit 30 is configured, for example, as a PLC (Programmable Logic Controller). The control unit 30 may also be configured as a computer system including a processor such as a CPU (Central Processing Unit), memory such as RAM (Random Access Memory) and ROM (Read Only Memory), input / output devices such as a touch panel, mouse, keyboard, and display, and communication devices such as a network card. The control unit 30 realizes its functions by operating each piece of hardware under the control of the processor based on a computer program stored in memory.

[0036] (Acquisition of temperature changes by the control unit) The control unit 30 acquires the temperature trend, plotting the molten metal temperature detected by the second temperature sensor 20 for each pouring process. The pouring process involves pouring molten metal from one pouring ladle LD2 into multiple molds MD. The pouring process begins when the pouring ladle LD2, transported to the pouring machine 10, pours into the first mold MD, and ends when the amount of molten metal in the pouring ladle LD2 falls below a predetermined amount by sequentially pouring into subsequent molds MD, or when pouring into the assigned number of molds MD is completed. In other words, one pouring process is associated with one pouring ladle LD2. For each pouring process, or in other words, for each pouring ladle LD2, the control unit 30 acquires the temperature trend, plotting the molten metal temperature detected by the second temperature sensor 20 for each frame. The temperature trend shows the relationship between the molten metal temperature and the casting number. The casting number is an identifier assigned to the mold into which the molten metal is poured. The temperature trend may also show the relationship between the molten metal temperature and time.

[0037] The control unit 30 is connected to the database 60, and the temperature changes for each pouring ladle LD2 may be stored in the database 60. For example, if there are two ladles as the pouring ladle LD2, a first ladle L1 and a second ladle L2, the temperature changes 601 of the molten metal in the first ladle L1 are stored, as well as the temperature changes 602 of the molten metal in the second ladle L2. Note that the number of pouring ladles LD2 is not limited to two; there may be one or three or more pouring ladles LD2. Since the series of processes of the casting equipment 100 are executed repeatedly, the pouring ladles LD2 are used repeatedly. In other words, multiple temperature changes for the same ladle may be stored. In this case, the database 60 may store the temperature changes of the same ladle separately in relation to time, or it may change the numbering system of the casting number and incorporate them into the same matrix.

[0038] The control unit 30 may further store the temperature transition for each ladle LD2 for each model. This is because the set temperature is determined according to the model. For example, if the ladle LD2 has two ladles, a first ladle L1 and a second ladle L2, and there are two models, a first model M1 and a second model M2, then not only the temperature transition 601 of the molten metal in the first ladle L1 and the temperature transition 602 of the molten metal in the second ladle L2 corresponding to the first model M1 will be stored, but also the temperature transition 701 of the molten metal in the first ladle L1 and the temperature transition 702 of the molten metal in the second ladle L2 corresponding to the second model M2. Note that the number of models is not limited to two; there may be one model or three or more models.

[0039] Figures 6(A) and (B) are graphs showing an example of the change in pouring temperature for each ladle. Pouring temperature refers to the temperature of the molten metal during the pouring process. In the graph shown in Figure 6(A), the vertical axis represents the pouring temperature of the first ladle L1 in the first model M1, and the horizontal axis represents the pouring number. In the graph shown in Figure 6(B), the vertical axis represents the pouring temperature of the second ladle L2 in the first model M1, and the horizontal axis represents the pouring number. As shown in Figures 6(A) and (B), it can be seen that the initial pouring temperature (the pouring temperature of pouring number "1") varies greatly. This variation is due to differences in the temperature of the molten metal in the melting furnace 2 and differences in the ladle transport conditions. Differences in ladle transport conditions can be largely standardized by using the casting equipment 100 shown in Figure 1, which automatically travels on rails and manages the time. Therefore, the main cause of the variation is the difference in the temperature of the molten metal in the melting furnace 2. To prevent molten metal flow problems even if variations occur, the molten metal temperature in melting furnace 2 is expected to be set to a higher temperature. However, such measures lead to a decrease in energy efficiency.

[0040] (Determination of the set temperature by the control unit) The control unit 30 determines the set temperature of the melting furnace 2. In order to resolve the conflicting issues of ensuring product quality and improving energy efficiency, the control unit 30 determines the optimal set temperature of the melting furnace 2 to be as low as possible without causing problems such as poor molten metal flow. The control unit 30 determines the set temperature of the melting furnace 2 when the operating mode is set to the mode for determining the set temperature (hereinafter referred to as the check mode). The check mode is set, for example, when a set temperature corresponding to the model is not stored in advance, or when a problem such as poor molten metal flow occurs. The check mode is a mode for analyzing the temperature transitions of multiple pouring ladles LD2 acquired in this mode. When the operating mode is set to the check mode, the control unit 30 generates molten metal at a pre-determined provisional set temperature, performs the pouring process multiple times using a model for which the set temperature is unknown, and acquires multiple temperature transitions. If a set temperature exists for a model that has a similar casting weight and casting plan to the target model, the provisional set temperature may be the set temperature of the similar model.

[0041] The control unit 30 obtains the lower limit temperature Td corresponding to the model used in the pouring process from the molding machine (not shown) as model information for the mold MD. The lower limit temperature Td is the limit temperature at which defects such as poor molten metal flow do not occur, and it differs for each model. The control unit 30 confirms that the lowest temperature in the temperature progression is equal to or greater than the lower limit temperature Td for each temperature progression.

[0042] The control unit 30 determines the set temperature of the melting furnace 2 based on multiple temperature transitions in which the lowest temperature is confirmed to be above the lower limit temperature Td. In order to determine the optimal set temperature of the melting furnace 2, the control unit 30 determines the upper limit temperature Tu during the pouring process. The upper limit temperature Tu is the highest temperature of the molten metal that can be reached during the pouring process. Since the temperature of the molten metal decreases over time, the upper limit temperature Tu is approximately the target value of the molten metal temperature poured into the first mold (casting mold MD).

[0043] The control unit 30 identifies the optimal temperature transition from among multiple temperature transitions that falls within the temperature range determined by the upper limit temperature Tu and a predetermined lower limit temperature Td. The control unit 30 determines the upper limit temperature Tu such that the ratio of the number of optimal temperature transitions included in the multiple temperature transitions to the number of multiple temperature transitions obtained is a predetermined ratio. As an example, the predetermined ratio is set in the range of 60% to 80%. The control unit 30 associates the determined upper limit temperature Tu with the model and stores it in memory or elsewhere.

[0044] Figure 7 is a graph showing the relationship between the cumulative number of pours and the pouring temperature. Figure 7 is a graph when the operating mode is set to check mode, and the same model was used for pouring. In Figure 7, the vertical axis is the pouring temperature (pouring temperature), and the horizontal axis is the cumulative number of pours. Figure 7 shows the temperature changes for each ladle number (ladle NO). Here, three pouring ladles with ladle numbers "1796", "1506", and "1290" are used. The order in which the pouring ladles LD2 arrive at the pouring machine 10 is ladle NO "1796" first, followed by ladle NO "1506", and finally ladle NO "1290", and this order is repeated. To improve visibility, the pouring temperature of pouring ladles arriving in odd-numbered order is shown as white data points, and the pouring temperature of pouring ladles arriving in even-numbered order is shown as black data points.

[0045] The control unit 30 determines the initial casting temperature for each temperature transition from among the temperature transitions that are above the lower limit temperature Td. This is because the initial casting temperature is generally the highest temperature in the temperature transition. To obtain more accurate data, the control unit 30 may also obtain the highest temperature for each temperature transition from among the temperature transitions that are above the lower limit temperature Td. In the example in Figure 7, these are 1414°C, 1428°C, 1418°C, 1410°C, 1403°C, 1408°C, 1407°C, 1407°C, 1410°C, and 1420°C, respectively. The control unit 30 sets the upper limit temperature Tu so that a predetermined proportion of these does not exceed the upper limit temperature Tu. If the predetermined proportion is 60%, the control unit 30 selects 6 of the above 10 casting temperatures (or highest temperatures) in descending order, and sets the 6th temperature as the upper limit temperature Tu. In the example in Figure 7, the upper limit temperature is 1410°C. As a result, the optimal temperature progression consists of six temperature progressions, from the 4th to the 9th (cumulative number of casts: 40 to 90).

[0046] The method for determining the upper limit temperature Tu of the control unit 30 described above is just one example. If the predetermined ratio is set to 60%, the control unit 30 may select five temperatures from the ten casting temperatures (or highest temperatures) described above in descending order of temperature, and set the fifth temperature as the upper limit temperature Tu. Alternatively, the control unit 30 may create a frequency distribution and calculate the upper limit temperature Tu that satisfies the predetermined ratio. Furthermore, if the number of temperature transitions does not match the predetermined ratio, for example, if the predetermined ratio is 60% but not divisible, the upper limit temperature Tu is determined to be the value closest to the predetermined ratio. Alternatively, the upper limit temperature Tu may be determined to be greater than or equal to the predetermined ratio and as close to the predetermined ratio as possible. Such cases are also included in the mode of determining the upper limit temperature "so that it becomes a predetermined ratio".

[0047] The control unit 30 determines the set temperature of the melting furnace 2, taking into account the temperature drop of the molten metal during the transport process, so that the temperature of the molten metal reaches the upper limit temperature Tu when the pouring ladle LD2 arrives at the pouring machine 10. The temperature drop of the molten metal during the transport process is the temperature drop due to the time taken for the transport process, and is acquired in advance for each model by the temperature drop check mode described later and stored in memory or the like. The control unit 30 refers to the memory and acquires the temperature drop corresponding to the model.

[0048] The control unit 30 determines the set temperature by adding the upper limit temperature Tu and the lower limit temperature corresponding to the model. The control unit 30 then stores the model and the set temperature in memory or elsewhere. As a result, when pouring molten metal into the same model, the control unit 30 can determine the set temperature of the melting furnace 2 by referring to the memory without executing a check mode. The control unit 30 displays information about the melting furnace, such as the set temperature, on the display device 50. The operator confirms the set temperature and adjusts the temperature of the molten metal in the melting furnace 2. This prevents the set temperature of the molten metal in the melting furnace 2 from being set unnecessarily high, thus determining a set temperature for the molten metal that takes energy efficiency into consideration.

[0049] The method for determining the set temperature of the control unit 30 described above is just one example. The control unit 30 may prepare a table that predefines the relationship between the upper limit temperature Tu, the decreasing temperature, and the set temperature, and determine the set temperature by inputting the upper limit temperature Tu and the decreasing temperature and referring to the table, without actually adding the upper limit temperature Tu and the decreasing temperature. In other words, the control unit 30 is a device that takes multiple temperature transitions as input data and outputs the set temperature as output data, and as long as the input data and output data have a predetermined relationship, the internal processing can be determined in any way. Specifically, the set temperature determined by the control unit 30 should satisfy the relationship that the set temperature is the sum of the upper limit temperature, which is determined so that the ratio of the number of optimal temperature transitions included in the multiple temperature transitions to the number of acquired temperature transitions is a predetermined ratio, and the decreasing temperature, which is the temperature that decreases during the transport process, when the optimal temperature transition is a temperature transition that falls within the temperature range determined by the upper limit temperature and a predetermined lower limit temperature.

[0050] The control unit 30 determines the temperature drop when the operating mode is set to the temperature drop check mode. The temperature drop check mode is set, for example, when the temperature drop corresponding to the model is not stored in advance, or when the difference between the ladle temperature at the start of pouring in the pouring ladle LD2 (the molten metal temperature of the first frame included in the acquired temperature transition) and the upper limit temperature Tu is not within a set range. The temperature drop check mode is a mode for analyzing the temperature data acquired in this mode. When the operating mode is set to the temperature drop check mode, the control unit 30 generates molten metal at a pre-determined provisional set temperature, performs the pouring process multiple times using a model for which the temperature drop is unknown, and acquires multiple temperature transitions. The control unit 30 calculates the difference between the receiving temperatures for multiple pouring ladles LD2 and the ladle temperature at the start of pouring in the pouring ladle LD2, and takes the moving average of the differences excluding abnormal values ​​(for example, ±30℃) as the temperature drop. The control unit 30 then stores the model and the temperature drop in memory or elsewhere, associating them. As a result, when pouring molten metal into the same model, the control unit 30 can determine the temperature drop by referring to memory without executing the temperature drop check mode. For example, the temperature drop in a standard ladle transport system is approximately 30°C to 50°C.

[0051] The temperature drop and upper temperature limit Tu may vary depending on the climate or the state of the molten metal. During normal operation after the check mode has ended, if the difference between the molten metal temperature of the first frame included in the acquired temperature transition and the upper temperature limit Tu is not within a preset range, the control unit 30 may display information related to the difference on the display device 50. The preset range is within the tolerance range, for example, about ±2°C. By displaying information related to the difference on the display device 50, the operator of the melting furnace 2 can operate the control unit 30 in check mode or temperature drop check mode.

[0052] During normal operation after the check mode has ended, if the pouring temperature falls below the lower limit temperature Td, the control unit 30 stops pouring from the pouring ladle LD2, drains the molten metal stored in the pouring ladle LD2, or returns it to the melting furnace 2. The control unit 30 may also display the molten metal temperature of the last frame included in the acquired temperature trend on the display device 50. This allows the operator to monitor the lowest temperature in the temperature trend and foresee that the pouring temperature will fall below the lower limit temperature Td.

[0053] (Operation of the pouring machine) Figure 8 is a flowchart illustrating an example of the operation of a set temperature determination system according to an exemplary embodiment. The flowchart shown in Figure 8 is executed before the start of the pouring process.

[0054] As shown in Figure 8, the control unit 30 performs a determination process (S10) to determine whether or not the temperature drop corresponding to the model is stored in memory. The control unit 30 refers to the memory to determine whether or not the temperature drop corresponding to the model is present. If the temperature drop corresponding to the model is not stored in memory, the control unit 30 performs an operation mode setting process (S12) to operate in temperature drop check mode. The control unit 30 operates in the aforementioned temperature drop check mode and acquires the temperature drop. Then, as a storage process (S14), the control unit 30 associates the model with the temperature drop and stores it in the control unit 30's memory or elsewhere. The flowchart shown in Figure 8 ends when the temperature drop corresponding to the model is stored in memory in the determination process (S10), or when the storage process (S14) is completed.

[0055] By executing the flowchart shown in Figure 8, the corresponding temperature drop for the model can be obtained before the pouring process.

[0056] Figure 9 is a flowchart illustrating an example of the operation of a set temperature determination system according to an exemplary embodiment. The flowchart shown in Figure 9 is executed before the start of the pouring process.

[0057] As shown in Figure 9, the control unit 30 performs a determination process (step S20) to determine whether or not the set temperature corresponding to the model is stored in memory. The control unit 30 refers to the memory to determine whether or not the set temperature corresponding to the model is stored. If the set temperature corresponding to the model is not stored in memory, the control unit 30 operates in check mode as an operation mode setting process (step S22). The control unit 30 operates in the check mode described above and determines the set temperature. Then, as a storage process (step S24), the control unit 30 stores the model and the set temperature in the memory of the control unit 30 or elsewhere, associating them. The flowchart shown in Figure 9 ends when the set temperature corresponding to the model is stored in memory in the determination process (step S20), and when the storage process (step S24) is completed.

[0058] By executing the flowchart shown in Figure 9, the set temperature corresponding to the model can be determined before the pouring process.

[0059] Figure 10 is a flowchart showing an example of the operation of a set temperature determination system according to an exemplary embodiment. The flowchart shown in Figure 10 is executed repeatedly at predetermined timings.

[0060] First, the control unit 30 determines whether or not the pouring process is in progress (step S30). For example, if the control unit 30 receives an operation signal from the pouring machine 10, it determines that the pouring process is in progress. If it is determined that the pouring process is in progress (step S30: YES), the control unit 30 determines whether or not the current casting is the first attempt (step S32). For example, based on the operation signal from the pouring machine 10, the control unit 30 determines whether or not the current casting is the first attempt. If the current casting is the first attempt (step S32: YES), the control unit 30 stores the molten metal temperature detected by the second temperature sensor 20 as the pouring start temperature in the database 60 (step S34).

[0061] Next, the control unit 30 determines whether the difference between the pouring start temperature and the upper limit temperature Tu is within the acceptable range (step S36). If it is determined that the difference is not within the acceptable range (step S36: NO), the control unit 30 displays information related to the difference on the display device 50 (step S40). The information related to the difference may be a numerical value or a greater than / less than relationship. This notifies the worker of the abnormality. The worker may stop the pouring process if necessary and check the temperature drop in the temperature drop check mode. When step S40 is completed, or when it is determined that the difference is within the acceptable range (step S36: YES), the flowchart shown in Figure 10 is completed.

[0062] Subsequently, processing begins from the beginning of the flowchart. If the second pour has already started, the current pour is not the first pour (step S32: NO), so the control unit 30 stores the molten metal temperature detected by the second temperature sensor 20 as the pouring start temperature in the database 60 (step S42).

[0063] The control unit 30 determines whether the molten metal temperature stored in step S42 is below the lower limit temperature Td (step S44). If the molten metal temperature is not below the lower limit temperature Td (step S44: NO), the flowchart shown in Figure 10 ends, and processing starts again from the beginning of the flowchart. If the molten metal temperature is below the lower limit temperature Td (step S44: YES), the pouring process ends (step S46). At this time, the remaining molten metal in the pouring ladle LD2 is either drained or returned to the melting furnace 2. Subsequently, the control unit 30 operates in check mode and determines the set temperature again (step S48). The control unit 30 may also operate in a low-temperature check mode.

[0064] If the pouring process is not underway in step S30, and step S48 is completed, the flowchart shown in Figure 10 ends.

[0065] (Summary of the embodiments) In the set temperature determination system 1, a pouring process is performed in which molten metal is poured sequentially from the pouring ladle LD2 into multiple molds MD. When the pouring ladle LD2 is empty, the next pouring process is performed in which molten metal is poured sequentially from the next pouring ladle LD2 into multiple molds MD. After each pouring process, a temperature transition is obtained by plotting the molten metal temperature detected by the second temperature sensor 20 for each frame. The upper limit temperature Tu is determined such that the ratio of the number of obtained temperature transitions to the number of optimal temperature transitions included in the multiple temperature transitions is a predetermined ratio. The optimal temperature transition is a temperature transition that falls within the temperature range determined by the upper limit temperature Tu and a predetermined lower limit temperature Td. The set temperature is determined by adding the temperature decrease temperature, which is the temperature that decreases during the transport process, and the determined upper limit temperature Tu.

[0066] In this way, the set temperature is determined, and the determined set temperature can be adopted as the set temperature for the next molten metal melt. The upper limit temperature used to determine the set temperature is determined such that the ratio of the number of temperature transitions to the number of optimal temperature transitions included in those transitions is a predetermined ratio (for example, 60-80%). Therefore, the set temperature determination system 1 can avoid setting the set temperature of the molten metal in the melting furnace 2 higher than necessary. Thus, the set temperature determination system 1 can determine the set temperature of the molten metal while considering energy efficiency.

[0067] Furthermore, the temperature setting determination system 1 can contribute to achieving carbon neutrality as a measure against global warming. For example, by lowering the set temperature of the melting furnace 2 by 20°C, it is expected that the heating time will be reduced by 70%. Let's estimate the amount of CO2 reduction in this case. The 3000KW melting furnace 2, which operates at a heating time of 4 hours / day and a heating time of 12 hours / day, is assumed to require 45kWh of electricity to raise the temperature by 100°C, and the conversion value of electricity to CO2 is 0.555 (Kg-CO2 / kWh). In this case, ((4h × 0.7) / day) / (12h / day) × 45kWh × (20°C / 100°C) × 0.555 gives approximately 1.17 (CO2Kg) / h. In other words, a CO2 reduction of 1.17Kg per hour is expected for one pouring machine 10. Assuming 22 working days per month, the calculation is (1.17 (CO2 kg) / h) × (12 hours / day) × (22 days / month) × (12 months / year) = 3707 kg / year. In other words, one pouring machine 10 is expected to reduce CO2 emissions by 3707 kg per year. By instructing the melting area to set the optimal melting furnace 2 temperature for the mold model number MD, it is possible to avoid setting the melting furnace 2 temperature to an unnecessarily high temperature, thereby saving energy. This is expected to reduce CO2 emissions and contribute to carbon neutrality.

[0068] Although various exemplary embodiments have been described above, the examples are not limited to those described above, and various omissions, substitutions, and modifications may be made.

[0069] For example, the method for determining the set temperature of the melting furnace 2 is not limited to the exemplary embodiment described above. In the exemplary embodiment described above, the control unit 30 selects multiple temperature transitions relating to the same type of model from among multiple temperature transitions, determines the upper limit temperature Tu and the lower limit temperature Td based on the selected multiple temperature transitions, and determines the set temperature of the melting furnace 2. The disclosure is not limited to this method, and for example, even if there are multiple types of models, the control unit 30 may select temperature transitions relating to some or all of the models, determine the upper limit temperature Tu and the lower limit temperature Td based on the selected multiple temperature transitions, and determine the set temperature of the melting furnace 2. In other words, the upper limit temperature Tu and the lower limit temperature Td common to some or all of the models may be determined. This allows the set temperature determination system to avoid determining the set temperature of the melting furnace 2 for each model when some or all of the models are similar, thereby improving the efficiency of the process. [Explanation of Symbols]

[0070] 1…Setting temperature determination system, 10…Pouring machine, 20…Second temperature sensor, 30…Control unit, 50…Display device, 100…Casting equipment.

Claims

1. In a pouring facility that repeats a series of processes including a receiving process in which the molten metal produced in a melting furnace that produces molten metal at a set temperature is received into a ladle, a transport process in which the ladle is transported to a pouring machine, and a pouring process in which the molten metal in the ladle is poured sequentially into a plurality of molds by the pouring machine, the system determines the set temperature of the molten metal, A temperature sensor for detecting the molten metal temperature at the tip of the ladle nozzle during the pouring process, For each of the pouring processes, a control unit acquires the temperature transition corresponding to the molten metal temperature detected by the temperature sensor and each of the multiple molds, Equipped with, The control unit, The temperature transition that falls within the temperature range determined by the upper temperature limit and the predetermined lower temperature limit is defined as the optimal temperature transition, and the upper temperature limit is determined such that the ratio of the number of acquired temperature transitions to the number of optimal temperature transitions included in the acquired temperature transitions is a predetermined ratio. The temperature obtained by adding the temperature that decreases during the transport process and the determined upper limit temperature is determined as the set temperature. system.

2. The control unit, From the temperature transitions of the pouring process, select the temperature transitions of the pouring process using the same model as the one used in the pouring process corresponding to the acquired temperature transitions, and determine the upper limit temperature such that a predetermined proportion of the selected temperature transitions of the pouring process become the optimal temperature transitions. The system according to claim 1, wherein the temperature obtained by adding the aforementioned decrease in temperature and the determined upper limit temperature is determined to be the set temperature corresponding to the model.

3. The system according to claim 1 or 2, wherein the control unit re-determines the upper limit temperature when the temperature transition includes a molten metal temperature lower than the lower limit temperature.

4. The system includes a display device that displays information related to the melting furnace, The system according to claim 1 or 2, wherein the control unit displays information relating to the difference on the display device if the difference between the molten metal temperature at the time of the first pouring into the mold and the upper limit temperature, which is included in the acquired temperature transition, is not within a preset range.

5. The system includes a display device that displays information related to the melting furnace, The system according to claim 1 or 2, wherein the control unit causes the display device to show the molten metal temperature at the time of the last pour into the mold, which is included in the acquired temperature transition.

6. In a pouring facility that repeats a series of processes including a receiving process in which the molten metal produced in a melting furnace that produces molten metal at a set temperature is received into a ladle, a transport process in which the ladle is transported to a pouring machine, and a pouring process in which the molten metal in the ladle is poured sequentially into a plurality of molds by the pouring machine, the system determines the set temperature of the molten metal, A temperature sensor for detecting the molten metal temperature at the tip of the ladle nozzle during the pouring process, A control unit acquires the temperature transitions corresponding to the molten metal temperature detected by the temperature sensor and each of the multiple molds for each pouring process, and determines the set temperature. Equipped with, The set temperature determined by the control unit is When the temperature transition that falls within the temperature range determined by the upper limit temperature and the predetermined lower limit temperature is defined as the optimal temperature transition, the relationship is satisfied in which the upper limit temperature, which is determined such that the ratio of the number of acquired temperature transitions to the number of the optimal temperature transitions included in the acquired temperature transitions is a predetermined ratio, and the set temperature is the sum of the upper limit temperature and the decrease temperature, which is the temperature that decreases during the transport process. system.

Images