Material heating device, program, and flow forming system

Abstract

To heat a heating object in a shorter time than conventional heating by heat conduction only.SOLUTION: A material heating device includes: a material temperature detection unit which detects the temperature of a material housed in a heating furnace; a material heating unit which heats the material together with the inside of the heating furnace; and a control unit which calculates, on the basis of the temperature of the material detected by the material temperature detection unit, the heating intensity for bringing the temperature of the material to a target temperature within a predetermined time and controls the material heating unit so as to heat the material at the calculated intensity.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The technology of the present disclosure relates to a material heating device, a program, and a flow forming system. [Background technology]

[0002] Patent Document 1 discloses a temperature control device that uses a heater to heat the inside of a heating furnace, thereby increasing the temperature inside the heating furnace to a predetermined final target temperature within a predetermined final target time. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2009-015545 A Summary of the Invention [Problem to be solved by the invention]

[0004] The material heating device typified by Patent Document 1 controls the air temperature in the heating furnace to heat the material to be heated to approximately the same temperature as the air in the heating furnace by thermal conduction from the air in the heating furnace. It takes a certain amount of time to heat the material by thermal conduction from the air in the heating furnace.

[0005] Incidentally, the material heated in the heating furnace may be subjected to plastic processing or the like in a post-process. The material to be plastically processed is required to be heated in a heating furnace in a short time and then transported to the plastic processing system.

[0006] The technology disclosed herein has been developed in consideration of the above-mentioned facts, and aims to provide a material heating device, a program, and a flow forming system that can heat a heating target in a shorter time than conventional heating by thermal conduction alone. [Means for solving the problem]

[0007] In order to achieve the above-mentioned object, a material heating device of a first aspect of the technology disclosed herein comprises a material temperature detection unit that detects the temperature of material contained in a heating furnace, a material heating unit that heats the material together with the inside of the heating furnace, and a control unit that calculates the heating intensity for raising the temperature of the material to a target temperature within a predetermined time based on the temperature of the material detected by the material temperature detection unit, and controls the material heating unit to heat the material at the calculated intensity. A program according to the second aspect of the technique of the present disclosure causes a computer to function as the control unit according to the first aspect. A flow forming system according to a third aspect of the technique of the present disclosure includes the material heating device according to the first aspect and a flow forming device. Effect of the Invention

[0008] The technology of the present disclosure can heat an object to be heated in a shorter time than conventional heating that relies solely on thermal conduction. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic diagram of an example of a flow forming system. [Diagram 2] FIG. 4 is a diagram showing an example of the arrangement position of a light heater. [Diagram 3] FIG. 2 is a block diagram of an example of a control device. [Figure 4] 13 is a flowchart of an example of a material temperature control program. [Diagram 5] Graphs of material temperature, furnace temperature, and light intensity. [Figure 6] 13 is a diagram showing a state in which the opening cover is opened from a state in which the opening cover covers the opening by the opening cover opening / closing motor. FIG. [Figure 7] FIG. 1 shows an example of a state in which a temperature-controlled material is removed from a heating furnace. [Figure 8] FIG. 4 is a cross-sectional view of a heating furnace according to a first modified example. [Figure 9] 13 is a graph of the temperature of the temperature-controlled material of the second variant. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, embodiments of the technology of the present disclosure will be described with reference to the drawings.

[0011] (composition) Fig. 1 is a schematic explanatory diagram of a flow forming system 100 according to the present embodiment. As shown in Fig. 1, the flow forming system 100 includes a material heating device 20 that heats a material 10, and a flow forming device 30 that molds the heated material 10. A molded product is manufactured by the flow forming system 100. Each component will be described in detail below. Flow forming is an example of plastic processing of metal, in which a plate or cup-shaped metal is rotated and deformed by pressing rollers against it to stretch it thin, gather it in one place to make it thick, or split and expand it into the desired shape. The flow forming system 100 is an example of a "flow forming system" of the technology of the present disclosure. The material heating device 20 is an example of a "material heating device" of the technology of the present disclosure.

[0012] <Material> The blank 10 is heated by a blank heating device 20, which will be described later, and then formed into a molded product by a flow forming device 30. The blank 10 is preferably provisionally molded into a predetermined shape by casting or the like, and a part of the blank is partially molded by the flow forming process.

[0013] The material of the blank 10 is preferably a material that can be deformed by pressing and is suitable for flow forming. Examples include metals such as iron or aluminum. Metals such as annealed iron or cast or forged aluminum are preferred. The blank 10 that has been provisionally molded by casting has blowholes in its metal structure, which causes low strength, but pressing the blank 10 makes the metal structure in the blank 10 denser, improving the strength of the blank 10. Therefore, the flow forming process makes it possible to form a molded product into a thin shape, and a lightweight and high-strength molded product can be obtained. The molded product may be an aluminum wheel. However, the molded product is not limited to an aluminum wheel. For example, the molded product may be an iron material (shaft or disk).

[0014] <Material heating device> The material heating device 20 includes a material temperature detection unit 15 that detects the temperature of the material 10 housed in the heating furnace 12 sealed with a thermal insulating material, and a material heating unit 16N that heats the material 10 together with the inside of the heating furnace 12. The material heating device 20 includes a control device 50 that calculates the heating intensity for the temperature of the material 10 to reach a target temperature within a predetermined time based on the temperature of the material 10 detected by the material temperature detection unit 15, and controls the material heating unit 16N to heat the material 10 with the calculated heating intensity. The predetermined time is, for example, the cycle time of a flow forming device 30 described later. The heating furnace 12 is an example of a "heating furnace" of the technology disclosed herein. The material temperature detection unit 15 is an example of a "material temperature detection unit" of the technology disclosed herein. The material heating unit 16N is an example of a "material heating unit" of the technology disclosed herein. The control device 50 is an example of a "control unit" of the technology disclosed herein. The material temperature detection unit 15 may be a temperature sensor, or may be a value estimated using a model or the like.

[0015] The material heating section 16N may be any type as long as it can heat the material 10 together with the inside of the heating furnace 12. Various heat sources are possible for the material heating section 16N. The heating heat source is preferably a heating section that does not emit carbon dioxide in a factory or the like, and is, for example, a heating means that uses electric energy or steam energy for heating, and specifically includes electromagnetic induction heating, high frequency heating, steam heating, fluidized bed heating, light heating, and the like. These heating heat sources can reduce the amount of carbon dioxide emitted during flow forming processing. In addition, these heating heat sources can reduce the amount of carbon dioxide emitted in a factory or the like to almost zero, and can provide a flow forming system that reduces the amount of carbon dioxide emitted, even compared to a heating section that uses a flame from a gas burner or the like.

[0016] Heat sources such as electromagnetic induction heating, high frequency heating, steam heating, fluidized bed heating, and light heating locally heat a part of the material 10. Since only a part of the material 10 is heated in this manner, there are advantages in that the heating time can be shortened and no carbon dioxide is emitted. Furthermore, deformation of the non-heated part can be suppressed.

[0017] Incidentally, aluminum has a lower melting point compared to iron and the like, and its Young's modulus becomes small at a relatively low temperature. Therefore, when the material 10 is aluminum, it is possible to heat it in a relatively short time not only by a gas furnace, high-frequency heating, or electromagnetic induction heating, but also by steam heating, fluidized sand heating, light heating, or other means.

[0018] Hereinafter, an optical heating unit that irradiates light onto the material 10, more specifically, multiple material heaters 16N1-16N12 will be described as an example of the material heating unit 16N. FIG. 2 is a diagram showing an example of the arrangement of the optical heaters 16N1-16N12. As shown in FIG. 2, the multiple material heaters 16N1-16N12 are arranged in an arc shape so as to surround the material 10. Each of the multiple material heaters 16N1-16N12 locally irradiates light onto the side surface of the material 10. Since light is irradiated onto the portion to be heated, the temperature rise in the portion not requiring heating can be relatively low. The material heaters 16N1 to 16N12 are examples of the "light heating section" and the "material heater" of the technology of the present disclosure.

[0019] The material heating device 20 heats the material 10 to a target temperature. For example, the target temperature is about 350°C to 400°C in the case of cast aluminum. This makes the material 10 soft and easy to roll, and reduces molding defects in the formed product after flow forming, thereby improving the yield. Below, an example of the target temperature will be described, taking 400°C as an example. In this case, as described later, the upper limit of the target temperature is, for example, 410°C, and the lower limit of the target temperature is, for example, 390°C.

[0020] The material heating apparatus 20 includes a stage 23 on which one material 10 is placed inside the heating furnace 12, and an elevator 22 that raises and lowers the stage. The material temperature detection unit 15 is disposed on the stage 23 at a position outside the area where the material 10 is placed.

[0021] The material heating device 20 includes a material replacement detection unit 19 (see FIG. 3) that is disposed in an area on the stage 23 where the material 10 is placed. When the material 10 leaves the stage 23, the detection signal from the material replacement detection unit 19, for example, falls. When the material 10 is placed on the stage 23, the detection signal from the material replacement detection unit 19, for example, rises. When the detection signal from the material replacement detection unit 19 rises after falling in this manner, it is detected that a new material 10 has been placed on the stage 23, that is, the replacement of the material 10.

[0022] The material heating device 20 heats one material 10 in one heating furnace 12. One material 10 is heated each time in accordance with the cycle time of the plastic processing of the flow forming process (the time from when the first material enters the flow forming device and is processed until the next material enters the flow forming device). In a conventional large heating furnace, since several tens of materials are heated at once, if a trouble occurs in the flow forming device 30 and the device is stopped, several tens of materials must be reheated after the trouble is resolved. In addition, the heating time is long because several tens of materials must be heated. This results in a large energy loss and unnecessary consumption of carbon dioxide. However, as described above, the material heating device 20 heats one material 10 in one heating furnace 12, so that when a trouble occurs in the flow forming device 30 and the material 10 needs to be reheated, the heating time can be relatively short, energy loss can be significantly reduced, and unnecessary carbon dioxide consumption can be suppressed. Note that, although one material 10 is heated in this embodiment, two or three materials may be heated in one heating furnace depending on the cycle time of the plastic processing of the flow forming process and the number of flow forming processes. Even in this case, energy loss is smaller than in the conventional case of heating a dozen or so materials, and unnecessary carbon dioxide consumption can be suppressed.

[0023] The material heating device 20 includes an in-furnace temperature detector 17 for detecting the temperature inside the furnace 12. When the temperature inside the furnace detected by the in-furnace temperature detector 17 is equal to or higher than the limit temperature, which is a predetermined value lower than the temperature at which the material heaters 16N1-16N12 break, the material heating device 20 controls the material heaters 16N1-16N12 so that the temperature inside the furnace 12 is equal to or lower than the limit temperature. This makes it possible to prevent the material heaters 16N1-16N12 from being broken down by the temperature inside the furnace 12. Even if the material heaters 16N1-16N12 are controlled so that the temperature inside the furnace 12 is equal to or lower than the limit temperature, the temperature inside the furnace 12 may not immediately decrease and may even rise. The predetermined value is determined in advance by experiments, etc., taking into account this rising temperature, so that the temperature inside the furnace does not reach the temperature at which the material heaters 16N1-16N12 break down. The limit temperature is, for example, 700°C. Instead of the furnace temperature detector 17, a material heating unit temperature detector for detecting the temperatures of the material heaters 16N1 to 16N12 may be provided and controlled in the same manner. The furnace temperature detection unit 17 is an example of the "furnace temperature detection unit" of the technology of the present disclosure. The furnace temperature detection unit 17 may be a temperature sensor, or may be a value estimated by a model or the like.

[0024] The material heating device 20 includes a lid opening / closing device 25 (see also FIG. 3) provided on the upper part of the heating furnace 12, and a conveying section 24 (see also FIG. 2) that conveys the material 10 from the material heating device 20 to the flow forming device 30.

[0025] When heating the raw material 10, the lid (i.e., the ceiling of the heating furnace 12) 12F is opened by the lid opening / closing device 25, the raw material 10 is placed on the stage 23 which is positioned at a position raised by the lifting device 22, the stage 23 is lowered by the lifting device 22, and the raw material 10 is positioned at a position surrounded by the multiple raw material heaters 16N1 to 16N12. The raw material 10 is irradiated with light by the multiple raw material heaters 16N1 to 16N12 and heated. The lid 12F is attached to the left and right side plates shown in Fig. 1 so as to be movable on each of the side plates in the direction toward the front side and the back side of the paper. The lid opening / closing device 25 is composed of, for example, a rack and pinion mechanism. Specifically, it includes a rack (not shown) provided on the upper part of the left and right side plates shown in Fig. 1, a pinion (not shown) provided on the lid 12F, and a motor (not shown) that generates a driving force to the pinion. When the motor rotates, the pinion moves on the rack while rotating. As a result, the lid 12F moves on the left and right side plates shown in Fig. 1 in the direction toward the front side and the back side of the paper.

[0026] When heating of the material 10 is completed, the lid 12F is moved by the lid opening / closing device 25 to open the heating furnace 12, the stage 23 is raised by the lifting device 22, and the material 10 placed on the stage 23 is transported by the transport unit 24 (also see FIG. 2) from the material heating device 20 to the flow forming device 30. The transport unit 24 is, for example, a belt conveyor, a transport rail, a robot arm, or the like.

[0027] An opening 12K is formed in the lid 12F of the heating furnace 20. The heating furnace 20 is equipped with an outside air intake device 20FM that takes in outside air through the opening 12K into the heating furnace 20. The outside air intake device 20FM is equipped with an opening lid 20F that opens and closes the opening 12K, and an opening lid opening / closing motor 20M that is connected to one end of the opening lid 20F and moves the opening lid 20F closer to or farther from the opening 12K. When the opening lid 20F is covered by the opening lid opening / closing motor 20M, the opening 12K is closed. When the opening lid 20F is gradually moved away from the state where it covers the opening 12K by the opening lid opening / closing motor 20M, the opening 12K is gradually opened from the closed state, and the amount of outside air taken into the heating furnace 20 increases.

[0028] <Flow forming equipment> The flow forming apparatus 30 rolls and shapes the material 10 heated by the material heating apparatus 20 by a flow forming process. The flow forming apparatus 30 includes a die 31 for forming the material 10 transported from the material heating apparatus 20, and a presser 33 for fixing the material to the die 31. The flow forming apparatus 30 includes a main shaft 32 that connects the die 31 to a drive unit (not shown) for rotating the die 31, and a processing tool 34 that presses the rotating material 10 against the die 31 to form it. The processing tool 34 for pressing the material 10 can be, for example, a processing roller or a spatula.

[0029] The flow forming process of the blank 10 will now be described.

[0030] The material 10 locally heated by the material heating device 20 is placed in a mold 31 , and then a presser 33 descends to fix the material 10 to the mold 31 .

[0031] The drive unit rotates the die 31 and the blank 10 around the axis of the spindle 32, and the processing tool 34 presses the rim portion 10A against the die 31 to form it. The pressing operation of the processing tool 34 may be performed once or multiple times.

[0032] <Flow forming system> As shown in Fig. 1, in the flow forming system 100, the flow forming apparatus 30 and the material heating apparatus 20 are configured as an integrated unit. "Integrated" means that the flow forming apparatus 30 and the material heating apparatus 20 are assembled into one apparatus as shown in Fig. 1, and also means that the positional relationship between the flow forming apparatus 30 and the material heating apparatus 20 is fixed.

[0033] This makes it possible to immediately perform flow forming while maintaining the temperature of the heated material 10 at a high level. In addition, since the heating time of the material 10 can be reduced to the minimum necessary, it is possible to improve energy efficiency, and thus it is possible to provide a flow forming system capable of reducing carbon dioxide emissions.

[0034] However, the flow forming apparatus 30 and the material heating apparatus 20 may be separate entities. If the flow forming apparatus and the material heating apparatus are separate entities, the degree of freedom in spatial arrangement can be increased compared to the case where they are integrated.

[0035] <Control device> Fig. 3 is a block diagram of an example of the control device 50. As shown in Fig. 3, the control device 50 is configured as a computer, and includes a processor 54, a non-volatile memory (NVM) 56, and a random access memory (RAM) 58. The processor 54, the NVM 56, and the RAM 58 are connected to a bus 60.

[0036] The processor 54 is a processing device including a DSP (Digital Signal Processor), a CPU (Central Processing Unit), and a GPU (Graphics Processing Unit), and the DSP and GPU operate under the control of the CPU and are responsible for executing the material temperature control process. Here, a processing device including a DSP, a CPU, and a GPU is given as an example of the processor 54, but this is merely one example, and the processor 54 may be one or more CPUs and DSPs with integrated GPU functions, one or more CPUs and DSPs without integrated GPU functions, or may be equipped with a TPU (Tensor Processing Unit).

[0037] The NVM 56 is a non-volatile storage device that stores various programs, various parameters, etc. The NVM 56 may be, for example, a flash memory (for example, an Electrically Erasable and Programmable Read Only Memory (EEPROM)).

[0038] The RAM 58 is a memory that temporarily stores information, and is used as a work memory by the processor 54. Examples of the RAM 58 include a dynamic random access memory (DRAM) and a static random access memory (SRAM).

[0039] The bus 60 is connected to an input unit 70, a display unit 72, a material temperature detection unit 15, an in-furnace temperature detection unit 17, a material exchange detection unit 19, an opening lid opening / closing motor 20M, a lid opening / closing device 25, a material heating unit 16N (material heaters 16N1 to 16N12), and a conveying unit 24. The input unit 70 is an example of the "input unit" of the technology of the present disclosure. The display unit 72 is an example of the "display unit" of the technology of the present disclosure.

[0040] The input unit 70 is a keyboard and a mouse, and receives instructions from a user and outputs a signal indicating the received instructions to the processor 54.

[0041] The display unit 72, under the control of the processor 54, presents various types of information to the user.

[0042] A material temperature control program 56P is stored in the NVM 56. The processor 54 reads the material temperature control program 56P from the NVM 56 and executes the read material temperature control program 56P on the RAM 58 to perform a material temperature control process. The processor 54 operates as the light emission processing unit 54A, the lid opening / closing processing unit 54B, the material temperature control unit 54C, and the furnace temperature control unit 54D in accordance with the material temperature control program 56P executed on the RAM 58, thereby realizing the material temperature control process. The material temperature control program 56P is an example of a "program" of the technology of the present disclosure.

[0043] (action) Next, the operation of the material heating apparatus 20 of this embodiment will be described.

[0044] FIG. 4 is a flowchart of an example of the material temperature control program.

[0045] The material temperature control program starts, for example, when the type and size of material 10, the target temperature of material 10, and the time required for the temperature of material 10 to reach the target temperature are input from input unit 70, and a command to start the material temperature control process is input.

[0046] The type and size of the material 10 may be input from an input unit (not shown) on the side of the flow forming apparatus 30. The type and size of the material 10 may be specified based on the image data input by the input unit 70, the image data being obtained by imaging the material 10 from an imaging unit that images the material 10.

[0047] The material temperature control process is a process for heating the material 10 by irradiating light from multiple material heaters 16N1 to 16N12 to the material 10 so that the temperature of the material 10 reaches a target temperature Tm by a scheduled heating time tn2 (t2, t12, t22) which is a predetermined time T from the time t1 (see FIG. 5), t11, or t21 when a command to start the material temperature control process is input.

[0048] In step 100, the material temperature control unit 54C determines whether or not a material replacement instruction has been input from the flow forming apparatus 30 or the input unit 70. If it is determined that a material replacement instruction has not been input, the material temperature control process proceeds to step 124. If it is determined that a material replacement instruction has been input, the material temperature control process proceeds to step 102.

[0049] In step 102, the material temperature control unit 54C controls the lid opening / closing device 25 to open the lid 12F, and controls the lifting device 22 to raise the stage 23, as shown in Fig. 7. The material 10 placed on the stage 23 is transported from the material heating device 20 to the flow forming device 30 by the transport unit 24. When the material 10 leaves the stage 23 to be transported to the flow forming device 30, the detection signal of the material exchange detection unit 19, for example, falls.

[0050] When the material 10 is transported from the material heating device 20 to the flow forming device 30 by the transport unit 24 as described above, the transport unit 24, for example, a robot arm, places a new material 10 on the stage 23. When the new material 10 is placed on the stage 23, the detection signal of the material replacement detection unit 19, for example, rises. When the detection signal of the material replacement detection unit 19 rises after the detection signal of the material replacement detection unit 19 falls in this way, it is detected that a new material 10 has been placed on the raised stage 23, that is, the replacement of the material 10. When the replacement of the material 10 is detected in this way, the material temperature control unit 54C controls the lifting device 22 to lower the stage 23 so that the material 10 is located at a position surrounded by the multiple material heaters 16N1 to 16N12, and controls the lid opening and closing device 25 to close the lid 12F.

[0051] In step 104, the light emission processing unit 54A controls the plurality of material heaters 16N1 to 16N12 so that light is irradiated to the material 10 at a predetermined set intensity Li. This starts light heating of the material 10.

[0052] In step 106 , the material temperature control section 54 C receives the material temperature Ts from the material temperature detection section 15 .

[0053] In step 108, material temperature control unit 54C calculates the increase or decrease in light intensity (ΔLi1) required to reach target temperature Tm in planned heating time tn2, based on the difference between current material temperature Ts and preset material temperature (measured value) Ts.

[0054] In this embodiment, an optimal temperature rise curve of the material 10 is set in advance by a heating test. The set material temperature (measured value) Ts is the temperature of the material 10 on the temperature rise curve at the time elapsed from the start of heating. The method of calculating the increase or decrease (ΔLi1) in light intensity to reach the target temperature Tm at the planned heating time tn2 is not limited to using the difference between the current material temperature Ts and the preset material temperature (measured value) Ts. For example, material temperature control unit 54C calculates the increase or decrease (ΔLi1) by artificial intelligence (AI). For example, the calculation is performed using a learning model that has been trained to calculate the increase or decrease (ΔLi1) to reach the target temperature Tm at the predetermined time T for each of the predetermined time T, the type and size of material 10, and the target temperature Tm. The learning model is stored in NVM 56 and is read out for use.

[0055] In step 110, the material temperature control unit 54C receives the furnace temperature Th from the furnace temperature detection unit 17.

[0056] In step 112, the material temperature control unit 54C predicts the time tx when the current furnace temperature Th becomes the limit temperature Tr based on the difference between the current furnace temperature Th and the set furnace temperature Th, and the increase or decrease in light intensity (ΔLi1). The limit temperature Tr is a temperature that is lower than the temperature at which the material heaters 16N1 to 16N12 break down by a predetermined value, as described above.

[0057] In this embodiment, an optimal temperature rise curve in the furnace is set in advance by a heating test. The set furnace temperature Th is the temperature in the furnace at the elapsed time from the start of heating on the temperature rise curve.

[0058] In step 114, the material temperature control unit 54C determines whether tn2 < tx, specifically, whether the scheduled heating time tn2 arrives earlier than the time tx when the current furnace temperature Th becomes the limit temperature Tr. If it is determined that tn2 < tx, the material temperature control process proceeds to step 118. If it is not determined that tn2 < tx, the material temperature control process proceeds to step 116. The scheduled heating time tn2 is an example of "when a predetermined time elapses". The time tx when the current furnace temperature Th becomes the limit temperature Tr is an example of "when the temperature in the heating furnace becomes the limit temperature that is lower than the temperature at which the material heating unit breaks down by a predetermined value".

[0059] In step 116, the material temperature control unit 54C calculates the increase or decrease in light intensity (ΔLi2) such that tn2 < tx. In this case, the material temperature control process proceeds to step 118.

[0060] In step 118, the light emission processing unit 54A adjusts the light intensity of the plurality of material heaters 16N1 to 16N12. When proceeding to step 118, first, in step 114, when it is determined that the scheduled heating time tn2 arrives earlier than the time tx when the current furnace temperature Th becomes the limit temperature Tr (tn2 < tx). In this case, in step 118, the light emission processing unit 54A controls the plurality of material heaters 16N1 to 16N12 so that the light intensity of the plurality of material heaters 16N1 to 16N12 increases or decreases by ΔLi1.

[0061] When step 114 is judged to be positive and the processing of step 118 is executed, light is irradiated from the multiple material heaters 16N1 to 16N12 to the material 10 so that the temperature of the material 10 reaches the target temperature Tm by the time t2 (i.e., the planned heating time tn2) when a predetermined time T has elapsed from the time t1 (see FIG. 5) when a command to start the material temperature control processing is input.

[0062] Secondly, when the process proceeds to step 118, there is a case where the process of step 116 has been executed. In this case, in step 118, the light emission processing unit 54A controls the multiple material heaters 16N1 to 16N12 so that the light intensities of the multiple material heaters 16N1 to 16N12 increase or decrease by ΔLi2.

[0063] By executing the process of step 118 after the process of step 116, the light intensity of the material heaters 16N1 to 16N12 is controlled so that the light intensity of the material heaters 16N1 to 16N12 is increased or decreased by ΔLi2. For example, as shown in FIG. 5, at time tx1, the light intensity is decreased by ΔLi2=L0. If the judgment of step 114 is positive and the material temperature control process proceeds to step 116, this is a case where if the light intensity of the material heaters 16N1 to 16N12 is kept as it is, the furnace temperature Th will reach the limit temperature Tr before the expected heating time tn2 arrives. Therefore, rather than lowering the light intensity because the furnace temperature Th has reached the limit temperature Tr, in this embodiment, the light emission processor 54A predicts that if the material 10 continues to be irradiated with light at the same light intensity, the furnace temperature Th will reach the limit temperature Tr before the material 10 reaches the target temperature Tm, and lowers the light intensity of the material heaters 16N1 to 16N12 in advance (during the process). After the process of step 116, when the process of step 118 is executed, first, from the time t1 (see FIG. 5) when the start command of the material temperature control process is input until the time t2 when a predetermined time T has elapsed (that is, the planned heating time tn2), light is irradiated from the plurality of material heaters 16N1 to 16N12 to the material 10 so that the temperature of the material 10 becomes the target temperature Tm. Second, before the temperature of the material 10 reaches the target temperature Tm, light is irradiated from the plurality of material heaters 16N1 to 16N12 to the material 10 so that the current furnace temperature Th does not become the limit temperature Tr.

[0064] In step 120, the material temperature control unit 54C takes in the material temperature Ts from the material temperature detection unit 15.

[0065] In step 122, the material temperature control unit 54C determines whether TmL < Ts. Here, TmL is the lower limit value of the target temperature of the material 10. When the target heating temperature is 400 ° C, the lower limit value is, for example, 390 ° C.

[0066] Step 122 is performed immediately after the start of light heating in step 104, and returns to step 106 many times until it is determined that TmL < Ts. During this period, the determinations in steps 114 and 116 are performed many times, and each time the light intensity is adjusted in step 118.

[0067] When it is determined in step 122 that TmL < Ts, the process proceeds to step 123. In step 123, the material control unit 54C determines whether Ts < Tmu. Here, Tmu is the upper limit value of the target temperature of the material 10. When the target heating temperature is 400 ° C, for example, the upper limit value is 410 ° C. If it is determined in step 123 that Ts < Tmu, the material temperature control process proceeds to step 100. However, if it is determined in step 123 that Ts is not less than Tmu, that is, if it is determined that Ts is greater than or equal to Tmu, the material temperature control process proceeds to step 124.

[0068] Even if it is determined in step 123 that Ts < Tmu and the process proceeds to step 100, if it is not determined in step 100 that there is an input of a material replacement instruction as described above, the material temperature control process proceeds to step 124.

[0069] In step 124, the furnace temperature control unit 54D takes in the furnace temperature Th from the furnace temperature detection unit 17.

[0070] In step 126, the furnace temperature control unit 54D determines whether Tr < Th.

[0071] As described above, Tr is the limit temperature at which the temperature of the air in the heating furnace is lower than a predetermined value by the temperature at which the material heater breaks. Therefore, in step 126, the furnace temperature control unit 54D determines whether the furnace temperature Th is greater than the limit temperature Tr. If it is determined that Tr < Th, the material temperature control process proceeds to step 134. If it is not determined that Tr < Th, the material temperature control process proceeds to step 128.

[0072] In step 128, the furnace temperature control unit 54D takes in the material temperature Ts from the material temperature detection unit 15.

[0073] In step 130, the furnace temperature control unit 54D determines whether Tmu < Ts, that is, whether the material temperature Ts is greater than the upper limit Tmu of the target temperature of the material 10. If it is determined that Tmu < Ts, the material temperature control process proceeds to step 134. If it is not determined that Tmu < Ts, the material temperature control process proceeds to step 132.

[0074] In step 132, the in-furnace temperature control unit 54D determines whether it is possible to calculate the increase or decrease (ΔLi3) in light intensity to maintain the material temperature (measured value) Ts within the allowable range (TmL < Ts < Tmu) from the current in-furnace temperature Th and the current material temperature Ts. If it is determined that the increase or decrease (ΔLi3) in light intensity can be calculated, the material temperature control process proceeds to step 118. If it is not determined that the increase or decrease (ΔLi3) in light intensity can be calculated, the material temperature control process proceeds to step 134.

[0075] In step 134, the light emission processing unit 54A stops the light heating of the material 10 by stopping the operation of the plurality of material heaters 16N1 to 16N12. As shown in FIG. 6, the in-furnace temperature control unit 54D operates the outside air intake device 20FM, specifically, operates the opening lid opening and closing motor 20M to move the opening lid 20F away from the opening 12K, thereby increasing the amount of outside air taken into the heating furnace 20.

[0076] In step 126, when it is determined that the in-furnace temperature Th is greater than the limit temperature Tr and the process proceeds to step 134, in step 134, the light heating of the material 10 is stopped, and the amount of outside air taken into the heating furnace 20 is increased so that the in-furnace temperature Th becomes equal to or lower than the limit temperature Tr. Therefore, it is possible to prevent the material heaters 16N1 to 16N12 from being damaged.

[0077] In step 130, when it is determined that the material temperature Ts is higher than the upper limit Tmu of the target temperature of the material 10, in step 134, the light heating of the material 10 is stopped, and the amount of outside air taken into the heating furnace 20 is increased. As a result, even when the temperature of the material 10 becomes higher than the upper limit Tmu of the target temperature, it is possible to quickly lower the temperature to a temperature equal to or lower than the upper limit Tmu.

[0078] In step 132, when it is determined that the increase or decrease (ΔLi3) in the light intensity for maintaining the material temperature (measured value) Ts within the allowable range can be calculated and the process proceeds to step 118, in step 118, the light emission processing unit 54A controls the plurality of material heaters 16N1 to 16N12 such that the light intensity of the plurality of material heaters 16N1 to 16N12 increases or decreases by ΔLi3. Therefore, the material temperature (measured value) Ts can be maintained within the allowable range (TmL < Ts < Tmu).

[0079] When the flow forming device 30 can accept the material 10 while the material temperature (measured value) Ts is maintained within the allowable range (TmL < Ts < Tmu), a material replacement instruction is input from the flow forming device 30 side to the input unit 70. In this case, step 100 results in an affirmative determination, and as described above, the lid 12F is opened by the lid opening and closing device 25 (see the time ty1 in FIG. 5). As shown in FIG. 7, the stage 23 is raised by the lifting device 22, and the material 10 placed on the stage 23 is conveyed from the material heating device 20 to the flow forming device 30 by the conveying unit 24 (also see FIG. 2). Thereafter, as described above, for example, a new material 10 is placed on the stage 23 by a robot arm, the stage 23 is lowered by the lifting device 22, and the material 10 is positioned at a position surrounded by the plurality of material heaters 16N1 to 16N12. The lid is closed by the lid opening and closing device 25. A start command for the material temperature control process is input from the flow forming device 30 (see the time t11 in FIG. 5).

[0080] The time E1 from the time ty1 to the time t11 in FIG. 5 is the replacement time of the material 10. Since the lid 12F is open, the temperature inside the furnace also drops. Between the time t2 and the time t11, light is irradiated from the plurality of material heaters 16N1 to 16N12 at a predetermined intensity. Note that between the time t2 and the time t11, the light may not be irradiated from the plurality of material heaters 16N1 to 16N12.

[0081] As described above, a command to start the material temperature control process is input (see time t11 in FIG. 5), and the material temperature control process in FIG. 4 is executed again. For example, at time tx2, it may be determined that tx≦tn2. In this case, the light intensity of the material heaters 16N1-16N12 is reduced by, for example, a predetermined value L0 (=ΔLi2) through the processes of steps 116 and 118. Meanwhile, in the flow forming apparatus 30, a flow forming process is performed.

[0082] When the heating of the material 10 from time t11 is completed (time t12 in FIG. 5), the material 10 is replaced (see time E2), and a command to start the material temperature control process is input (see time t21 in FIG. 5). The material temperature control process in FIG. 4 is executed again. Meanwhile, in the flow forming device 30, a flow forming process is performed.

[0083] The period from time t11 to time t21 is the cycle time S of the plastic processing of the heated material 10.

[0084] When the heating of the material 10 from time t21 is completed (time t22 in Figure 5), the material 10 is replaced, but at time W shown in Figure 5, the material 10 remains placed on the stage 23, waiting to be transported, until a signal is input from the flow forming device 30 indicating that new material 10 can be accepted, and the temperature of the material 10 is maintained near Tm by suppressing light heating and adjusting the temperature inside the furnace. In the example shown in Figure 5, a signal indicating that new material 10 can be accepted is not input from the flow forming device 30, and the temperature of the material 10 exceeds the allowable range or the temperature inside the furnace exceeds the limit value, so light irradiation from the multiple material heaters 16N1 to 16N12 is stopped and the temperature inside the furnace is lowered by forced ventilation, and as a result, the temperature of the material is also lowered.

[0085] (effect) As described above, in this embodiment, the heating target can be heated in a shorter time than the conventional heating by only thermal conduction. Specifically, when the material 10 is, for example, aluminum, several tens of minutes are required for the temperature of the material to reach the target temperature when heating by only thermal conduction. In contrast, in this embodiment, the material is heated by both thermal conduction heating and optical heating, so that the time required for the temperature of the material to reach the target temperature is only a few minutes. Therefore, in this embodiment, the material can be heated in a shorter time than the conventional heating by only thermal conduction. Therefore, the predetermined time required for the temperature of the material to reach the target temperature can be made shorter. Therefore, the material can be delivered to the flow forming device 30 more quickly. Therefore, simultaneous heating can be performed in accordance with the cycle time of the plastic processing, and it is possible to respond to daily stoppages and emergency stoppages of the plastic processing device.

[0086] In this embodiment, the temperature of the air in the heating furnace is detected by the furnace temperature detector 17, and when the temperature of the air in the heating furnace is equal to or higher than a limit temperature that is a predetermined value lower than the temperature at which the material heater breaks down, the material heater is controlled so that the temperature of the air in the heating furnace is kept below the limit temperature. Therefore, in this embodiment, it is possible to prevent the material heater from breaking down.

[0087] In this embodiment, the material is heated by irradiating light from multiple material heaters arranged in an arc onto the material. Another method for heating in a short time is high-frequency heating, in which a high-frequency current is passed through a coil to heat the material placed inside the coil, but this method requires adjustment over several days if the gap between the coil and the material changes by even a few millimeters. However, in this embodiment, as long as the material is placed within an arc where multiple material heaters are arranged, it can be heated immediately even if the distance between the material heaters and the material changes due to a change in the material. Therefore, in this embodiment, it is possible to eliminate the need to adjust the distance between the multiple material heaters and the material.

[0088] In this embodiment, the material is heated by a heating section that does not emit carbon dioxide. Therefore, in this embodiment, it is possible to suppress the emission of carbon dioxide compared to a heating section that uses a flame from a burner or the like. In this embodiment, light heating is used, but the technology of the present disclosure is not limited to this. For example, electromagnetic induction heating, high frequency heating, steam heating, or fluidized bed heating may be used.

[0089] In this embodiment, a part of the material is locally heated by irradiating the material with light from multiple material heaters. This makes it possible to relatively reduce the temperature rise in the parts that do not need to be heated. In addition, in this embodiment, when aluminum is heated by the light heating of this embodiment, no carbon dioxide is generated at all.

[0090] In this embodiment, the flow forming device and the material heating device are integrated into one unit. This makes it possible to immediately perform flow forming while keeping the temperature of the heated material high. This reduces the heating time of the metal material to the minimum necessary and increases energy efficiency, making it possible to provide a flow forming system that can reduce carbon dioxide emissions.

[0091] In the material heating device of this embodiment, one heating furnace heats one material. One material 10 is heated each time in accordance with the cycle time of the plastic processing of the flow forming process. Therefore, when a problem occurs in the flow forming device 30 and the material 10 is reheated in the material heating device 20, the heating time can be significantly shortened compared to the case where several tens of materials are reheated in a large heating furnace, energy loss can be eliminated, and unnecessary carbon dioxide consumption can be suppressed. Furthermore, this embodiment can reduce the area and cost required to install the material heating device.

[0092] In addition, in this embodiment, the number of materials waiting in the material heating device while maintaining the temperature for flow forming can be reduced to one, and the scale of the material heating device can be reduced. This reduces the time it takes to heat up the material heating device, and it can be started up in a short time from a stopped state. Therefore, when production is stopped on holidays, etc., there is no need to keep the material heating device running, and the energy efficiency of the entire flow forming system can be significantly improved.

[0093] (Modification) <First Modification> FIG. 8 is a cross-sectional view of the heating furnace of the first modified example. As shown in FIG. 8, the material heating device further includes a moving mechanism (e.g., a rack-and-pinion mechanism) 116N1 for moving the material heater 16N1. The other material heaters 16N2 to 16N12 are also provided with moving mechanisms. The control device 50 controls the moving mechanisms so that each of the material heaters 16N1 to 16N12 moves to within a predetermined distance from the material 10 based on the size and shape of the material 10. Thus, in the material heating device of the first modified example, even if the size and shape of the material change, the material heater is moved to accommodate the change. Therefore, even if the size and shape of the material change in the material heating device of the first modified example, a single material heating device can accommodate the change. The moving mechanism 16N1 and the like are examples of the "moving mechanism" of the technology of the present disclosure.

[0094] <Second Modification> FIG. 9 is a graph of the temperature of the temperature-controlled material in the second modified example. In the embodiment described above, the heating start temperatures of the material are approximately the same, but the technology of the present disclosure is not limited to this. As shown in FIG. 9, the heating start temperatures of the material may be A>B>C. Even if the material heating start temperatures are different in this way, the control device 50 calculates the heating strength for raising the temperature of the material 10 to the target temperature Tm within a predetermined time T, and controls the material heating unit to heat the material with the calculated strength. Therefore, even if the material heating start temperatures are different, the temperature of the material can be raised to the target temperature Tm within a predetermined time.

[0095] <Third Modification> In the third modification, the temperatures acquired in steps 106, 110, 120, 124, and 128 of the material temperature control process (FIG. 4) in the above-described embodiment are displayed on the display unit 72 in the form of a graph with the elapsed time on the horizontal axis and the temperature on the vertical axis, as shown in FIG. 5. This allows the operator to check whether the temperature control inside the furnace is working properly.

[0096] <Fourth modified example> In the fourth modified example, the heating furnace 20 further includes an internal heating section that heats the air in the heating furnace 20. The internal heating section may be a heating section that does not emit carbon dioxide (for example, a heating section that utilizes electromagnetic induction heating, high frequency heating, steam heating, fluidized bed heating, or light heating) or a heating section that uses flame from a gas burner or the like. The heating section in the heating furnace of the fifth modified example is an example of the "heating section in the heating furnace" of the technology of the present disclosure.

[0097] <Other Modifications> In the above embodiment, an example in which the material temperature control program 56P is stored in the NVM 56 has been described, but the technology of the present disclosure is not limited to this. For example, the material temperature control program 56P may be stored in a portable computer-readable non-transitory storage medium such as an SSD, a USB memory, or a magnetic tape. The material temperature control program 56P stored in the non-transitory storage medium is installed in the computer of the control device 50. The processor 54 executes the material temperature control process in accordance with the material temperature control program 56P.

[0098] Furthermore, the material temperature control program 56P may be stored in a storage device such as another computer or a server device connected to the material heating apparatus 20 via a network, and the material temperature control program 56P may be downloaded and installed in the material heating apparatus 20 in response to a request from the material heating apparatus 20.

[0099] It is not necessary to store the entire material temperature control program 56P in a storage device of another computer or server device connected to the material heating apparatus 20, or in the NVM 56; only a part of the material temperature control program 56P may be stored therein.

[0100] In the above embodiment, the technology of the present disclosure is described by way of an example in which the technology is realized by a software configuration, but the technology of the present disclosure is not limited to this, and may be applied to devices including an ASIC (Application Specific Integrated Circuit), an FPGA (Field Programmable Gate Array), or a PLD (Programmable Logic Device). Also, a combination of a hardware configuration and a software configuration may be used.

[0101] The hardware resources for executing the material temperature control process described in the above embodiment can be various processors as shown below. An example of the processor is a CPU, which is a general-purpose processor that functions as a hardware resource for executing the material temperature control process by executing software, i.e., a program. Another example of the processor is a dedicated electronic circuit, which is a processor having a circuit configuration designed specifically for executing a specific process, such as an FPGA, PLD, or ASIC. Each processor has a built-in or connected memory, and each processor uses the memory to execute the material temperature control process.

[0102] The hardware resource for executing the material temperature control process may be one of these various processors, or may be a combination of two or more processors of the same or different types (for example, a combination of multiple FPGAs, or a combination of a CPU and an FPGA). Also, the hardware resource for executing the material temperature control process may be a single processor.

[0103] As an example of a configuration using one processor, first, one or more CPUs and software are combined to configure one processor, and this processor functions as a hardware resource that executes the material temperature control process. Second, there is a configuration in which a processor is used that realizes the functions of the entire system, including multiple hardware resources that execute the material temperature control process, on a single IC (Integrated Circuit) chip, as typified by SoC (System-on-a-chip). In this way, the material temperature control process is realized using one or more of the above-mentioned various processors as hardware resources.

[0104] Furthermore, more specifically, the hardware structure of these various processors can be an electronic circuit that combines circuit elements such as semiconductor elements. The above-mentioned material temperature control process is merely an example. It goes without saying that unnecessary steps may be deleted, new steps may be added, or the order of processes may be changed without departing from the spirit of the invention.

[0105] The above description and illustrations are detailed descriptions of the parts related to the technology of the present disclosure, and are merely an example of the technology of the present disclosure. For example, the above description of the configuration, function, action, and effect is an example of the configuration, function, action, and effect of the parts related to the technology of the present disclosure. Therefore, it goes without saying that unnecessary parts may be deleted, new elements may be added, or replacements may be made to the above description and illustrations, within the scope of the gist of the technology of the present disclosure. In addition, in order to avoid confusion and to facilitate understanding of the parts related to the technology of the present disclosure, the above description and illustrations omit explanations of technical common sense that do not require explanation in order to enable the implementation of the technology of the present disclosure.

[0106] All publications, patent applications, and standards mentioned in this specification are herein incorporated by reference to the same extent as if each individual publication, patent application, and standard was specifically and individually indicated to be incorporated by reference. [Explanation of symbols]

[0107] 10. Materials 15 Material temperature detection unit 12 Furnace 16N material heating section 16N1~16N12 Material heater 20 Material heating device 20FM Fresh air intake device 22 Lifting section 23 Stage 24 Conveyor 25 Lid opening and closing device 30 Flow forming equipment 50 Control device 56P Material temperature control program 100 Flow Forming System

Claims

1. Comprising a light heating device provided in a heating furnace, The light heating device directly heats a material provided in the heating furnace by light heating, and heats the material by heat conduction when the air in the sealed heating furnace is heated by the light heating, characterized in that, A material heating device.

2. The light heating device includes a plurality of material heaters arranged to surround the material, The material heating device according to claim 1.

3. Further comprising a furnace internal temperature detection unit for detecting the temperature inside the heating furnace, The material heating device according to claim 2.

4. A moving mechanism for moving each of the plurality of material heaters, A control unit for controlling the moving mechanism so that each of the plurality of material heaters moves within a predetermined distance from the material based on the size of the material, The material heating device according to claim 2, further comprising.

5. Further comprising a furnace internal temperature detection unit for detecting the temperature inside the heating furnace, The control unit, Based on the temperature inside the heating furnace detected by the furnace internal temperature detection unit, when the temperature inside the heating furnace becomes a limit temperature that is a predetermined value lower than the temperature at which the light heating device breaks down, it is determined whether it arrives earlier than when a predetermined time elapses. If the determination is an affirmative determination, after the predetermined time elapses, the material heater is controlled so that the temperature inside the heating furnace becomes the limit temperature. The material heating device according to claim 4.

6. Further comprising an outside air intake device for taking in outside air into the heating furnace, The control unit controls the outside air intake device so that when the temperature inside the heating furnace detected inside the heating furnace is higher than a limit temperature that is a predetermined value lower than the temperature at which the light heating device breaks down, the temperature inside the heating furnace becomes equal to or lower than the limit temperature by taking in the outside air. The material heating device according to claim 4.

7. The material heating device according to any one of claims 1 to 6, A flow forming device, A flow forming system comprising.

8. A light heating device provided in a sealed heating furnace directly heats a material provided in the heating furnace by irradiating light on the material, The light heating device heats the material by heat conduction generated when the air in the heating furnace is heated by irradiating light on the material, A material heating method including.

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