Selecting device and selecting method

Abstract

To perform selection of a material of a crushed piece of a metal product at a lower price, and in turn prevent the generation of waste.SOLUTION: A selecting device conveys crushed pieces of a metal product, applies a magnetic field to the crushed pieces during the conveyance of the crushed pieces, acquires temperature information of the crushed pieces to which the magnetic field is applied, and performs selection of a crushed piece on the basis of the temperature information.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a sorting device and a sorting method. [Background technology]

[0002] Conventionally, metal recycling involves crushing metal products such as automobiles and sorting the resulting mixture according to its intended use. Patent Document 1 discloses a technique for identifying wrinkles from the surface information of the crushed pieces and sorting the crushed pieces according to the content of added metals contained in the crushed metal pieces based on the proportion of wrinkles on the surface. Furthermore, there is also a technique for measuring the density of a material using X-rays and identifying the material of the crushed pieces based on the measured density. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6726753 Summary of the Invention [Problem to be solved by the invention]

[0004] However, sorting using X-rays requires expensive equipment, making it difficult to easily identify the material of the fragments.

[0005] Therefore, an object of the present invention is to sort the materials of crushed pieces of metal products more inexpensively, thereby preventing the generation of waste. [Means for solving the problem]

[0006] According to the present invention, a conveying unit that conveys crushed pieces of metal products; a magnetic field applying unit that applies a magnetic field to the fragments while the fragments are being transported; an acquisition unit that acquires temperature information of the fragments to which the magnetic field has been applied; a sorting unit that sorts the fragments based on the temperature information; A sorting device is provided, comprising: [Effects of the Invention]

[0007] According to the present invention, it is possible to sort the materials of the crushed pieces of metal products at lower cost, thereby preventing the generation of waste. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a diagram showing an example of a sorting system including a sorting device according to an embodiment. [Figure 2] 5A and 5B are diagrams for explaining an example of an infrared image according to the embodiment. [Figure 3] 10 is a flowchart showing an example of a selection process according to the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, the embodiments will be described in detail with reference to the accompanying drawings. Note that the following embodiments do not limit the scope of the invention as claimed, and not all combinations of features described in the embodiments are necessarily essential to the invention. Two or more of the features described in the embodiments may be combined in any desired manner. Furthermore, the same reference numerals are used to designate identical or similar components, and redundant descriptions will be omitted.

[0010] The sorting device according to this embodiment applies a magnetic field to the fragments of metal products while they are being transported. The sorting device then acquires temperature information about the fragments to which the magnetic field has been applied and sorts the fragments based on the temperature information. The configuration of such a sorting device will be described below.

[0011] Fig. 1 is a schematic diagram showing an example of the configuration of a sorting device 1 according to this embodiment. Fig. 1(A) is an overhead view of a sorting system using the sorting device 1, and Fig. 1(B) is a side view of the sorting system using the sorting device 1. Hereinafter, the sorting system using the sorting device 1 may be simply referred to as the "sorting system."

[0012] The sorting device 1 sorts out crushed pieces of metal products crushed by a crusher (shredder) (not shown). Any crusher commonly used for crushing metal products can be used depending on the size or shape of the crushed pieces to be generated. For example, the crusher may be a compaction crusher such as a press crusher, a drilling crusher that performs cutting using a drill or the like, a refiner, a hammer crusher, or a shear crusher such as a uniaxial crusher or biaxial crusher. In FIG. 1, the crushed pieces are indicated by OB1 to OB3. The sorting system in FIG. 1 includes a conveying unit 11, an information acquiring unit 12, a sorting unit 13, a control unit 14, and a magnetic field applying unit 15.

[0013] The transport unit 11 is a transport mechanism that transports the crushed pieces. In the example of Fig. 1(B), the transport unit 11 is composed of a belt conveyor 111 and a motor 112, and OB1 to OB3 on the belt conveyor 111 are transported in the transport direction (X-axis direction) by driving the motor 112.

[0014] The information acquisition unit 12 acquires information about the broken pieces transported by the transport unit 11. In the example of FIG. 1(B), the information acquisition unit 12 is composed of an optical image capture unit 12a that captures optical images using an optical system and an infrared image capture unit 12b that captures infrared images using infrared rays as information about the broken pieces. Note that the optical image capture unit 12a and the infrared image capture unit 12b according to this embodiment are disposed above (directly above) the belt conveyor 111.

[0015] In this embodiment, the control unit 14 acquires position information of each fragment on the belt conveyor 111 based on the optical image acquired by the optical image capturing unit 12a. The sorting unit 13, which will be described later, uses this position information to identify the fragments and switch their destination for sorting. This position information may also be referenced in the magnetic field application process by the magnetic field application unit 15, which will be described later, or the image capture process by the infrared image capturing unit 12b. The infrared image capturing unit 12b according to this embodiment captures images of the fragments on the belt conveyor in the infrared range and generates an infrared image as temperature information of the fragments. Here, the temperature information is referenced by the brightness value in the infrared image.

[0016] The sorting unit 13 sorts the crushed pieces transported by the transport unit 11. In the example of FIG. 1(B), the sorting unit 13 is composed of a kicker 131 for depositing the crushed pieces transported on the belt conveyor 111 into a corresponding tray depending on the sorting result, and a motor 132 for driving the kicker 131 to change the destination of the crushed pieces. Here, the kicker 131 is a plate-shaped member, and is configured to change the tray into which the transported crushed pieces are deposited by changing its orientation relative to the belt conveyor 111 through the driving of the motor 132. Also, in the example of FIG. 1, trays 19a and 19b are shown as trays to which the crushed pieces are transported, but the types of pieces to be sorted are not limited to two.

[0017] The control unit 14 controls the transport unit 11, the information acquisition unit 12, the sorting unit 13, and the magnetic field application unit 15 (described later). The control unit 14 according to this embodiment controls the magnetic field application unit 15 to apply a magnetic field to the crushed fragments while the transport unit 11 is transporting the crushed fragments, and controls the infrared image capture unit 12b to acquire temperature information of the crushed fragments to which the magnetic field has been applied. The control unit 14 then controls the sorting unit 13 to sort the crushed fragments based on the temperature information. The control unit 14 is a computer control unit, and is assumed to include a CPU and memory. However, the control unit 14 is not limited to this as long as it can similarly control each process. For example, the control unit 14 may be a server device, or the functions performed by the control unit 14 may be implemented by multiple devices.

[0018] The magnetic field application unit 15 applies a magnetic field to the crushed pieces being transported by the transport unit 11. For example, the magnetic field application unit 15 may be an electromagnetic induction coil disposed below (directly below) the belt conveyor 111, and the magnetic field may be excited by current flow from the control unit 14. The time for which the magnetic field is applied to each crushed piece by the magnetic field application unit 15 can be arbitrarily set depending on the expected material and the strength of the magnetic field to be applied, and may be, for example, 1 millisecond or more, 3 milliseconds or more, 5 milliseconds or more, 10 milliseconds or more, 100 milliseconds or less, 75 milliseconds or less, 50 milliseconds or less, 30 milliseconds or less, or 20 milliseconds or less. Note that the magnetic field application time here may refer to the time for which the magnetic field is applied by the magnetic field application unit 15 once, or the time for which each crushed piece is subjected to a magnetic field due to the driving of the belt conveyor 111 while the magnetic field is continuously applied.

[0019] As an example, consider the case where the material of the fragments is iron, aluminum, or a mixture of these. When a magnetic field is applied to iron fragments, which are magnetic, eddy currents are generated, and resistance generates heat, causing the temperature to rise. On the other hand, when a magnetic field is applied to aluminum fragments, they are non-magnetic, so heat generation due to overcurrent does not occur. Furthermore, if the fragments are a mixture of iron and aluminum (fragments in which the iron and aluminum portions are joined), application of a magnetic field will generate heat in the iron portions. Hereinafter, when we simply say "heating" the fragments, we mean the process of generating heat by applying such a magnetic field.

[0020] Furthermore, the shapes of the fragments vary depending on the material of the part. For example, when a mild steel plate with a thickness of 1.0 mm or less (e.g., an ultra-low carbon rolled steel plate used for exterior panels) is crushed, the fragments will be crumpled at small intervals. When a mild steel plate with a thickness of 2.0 mm or more (e.g., a hot-rolled steel plate used for reinforcing members) is crushed, the fragments will be crushed at large intervals. When a high-tensile steel plate with a thickness of 1.0 mm or more (e.g., a car body frame component) is crushed, the fragments will be flat without being crushed. Even for the same type of part (e.g., an exterior panel), the shape of the fragments may vary depending on whether the material is iron or aluminum. Furthermore, for example, structural steel such as Cu wire, brazed parts containing Cu, or bolts, which are not the fragments to be sorted, may be mixed in as fragments. Depending on these shapes or the presence of foreign matter, the temperature conditions (particularly the temperature distribution) caused by the application of a magnetic field may change.

[0021] The sorting device 1 according to this embodiment can perform sorting by determining the material of the crushed fragments according to the temperature of the crushed fragments caused by the application of such a magnetic field. For example, the sorting unit 13 may use a pre-trained machine learning model to input an infrared image of the crushed fragments and sort the crushed fragments.

[0022] The sorting process performed here is not limited to this, as long as it is a process that determines the material of the crushed fragments (and their shape, etc.) based on the temperature condition of the crushed fragments caused by the application of a magnetic field. For example, the material of the crushed fragments may be determined based on information indicating the temperature distribution extracted from an infrared image. Furthermore, a machine learning model may be trained in advance so that the information indicating such temperature distribution is used as input to the machine learning model to estimate the material of the crushed fragments.

[0023] Here, the information indicating the temperature distribution can be emissivity calculated from the brightness of an infrared image detected at a constant temperature. For example, the information indicating the temperature distribution can be the change in the temperature distribution of the fragments over time after the application of the magnetic field has ended (obtained over time by the infrared image capturing unit 12a). This processing makes it possible to sort the fragments taking into account differences in thermal conductivity depending on the material, or differences in temperature distribution due to differences in plate thickness or crushed shape. The information indicating the temperature distribution can also be the reflectance (evaluated by the brightness of the infrared image) when light of a specific wavelength is applied to the fragments.

[0024] FIG. 2 is an infrared image illustrating an example of the change in temperature distribution of the fragments over time. The fragments 210 included in the image shown in FIG. 2 are made of iron, but also contain a brazed portion 211 containing Cu as a brazing material. FIG. 2 shows image 201 of the fragments before heating, image 202 of the fragments immediately after heating, image 203 of the fragments a predetermined time T1 after heating, and image 204 of the fragments a predetermined time T2 after heating. FIG. 2 also shows graph 205 illustrating the change in temperature distribution in images 201-204.

[0025] 2, the image of the broken piece 210 shows the blaze portion 211 and the steel plate surface 212, and the temperature distribution changes differently between them. As shown in image 201, in image 201 before heating, there is no difference in temperature between the blaze portion 211 and the steel plate surface 212, but the temperature rise in the blaze portion 211 is stronger in response to heating, and the temperature drop over time is smaller in the blaze portion 211.

[0026] Even when using crushed fragments that are a mixture of iron and aluminum, the temperature of the iron parts rises when a magnetic field is applied, while the temperature of the aluminum parts rises by a smaller amount than the iron parts (or does not rise at all).By using temperature distribution information, including changes in temperature distribution, as training data and training a machine learning model based on infrared images, it becomes possible to perform sorting using image recognition processing that reflects characteristics such as differences in thermal conductivity depending on the materials contained in the crushed fragments in the training data.

[0027] In this embodiment, prior to the sorting process in the sorting system shown in Fig. 1, the fragments that are sorted by known pre-processing to remove resin materials and the like are treated as the fragments OB1 to OB3 to be sorted. This pre-processing can be performed using known techniques for separating crushed metal products. For example, to remove specific materials such as resin materials, pre-processing such as wind sorting, electromagnetic induction sorting, gravity sorting, color sorting, or XRT may be performed.

[0028] Here, we consider a case where resin materials are removed by air sorting or other pre-processing, leaving behind crushed pieces of iron material, crushed pieces of aluminum material, and crushed pieces of a mixture of iron and aluminum materials. Hereinafter, the term "crushed pieces of a mixture" refers to such crushed pieces of iron and aluminum materials. In this case, further pre-processing by magnetic sorting can separate the crushed pieces into those containing iron material and those not containing iron material.

[0029] For example, by sufficiently increasing the magnetic strength during magnetic separation, it is possible to simultaneously extract iron material fragments and mixture fragments. The sorting device 1 can process the iron material fragments and mixture fragments extracted by magnetic separation, and perform a sorting process on them. Furthermore, by sufficiently decreasing the magnetic strength during magnetic separation, it is possible to avoid extracting mixture fragments during magnetic separation and leave aluminum material fragments and mixture fragments. The sorting device 1 can also process the aluminum material fragments and mixture fragments extracted (left unextracted) during magnetic separation, and perform a sorting process on them. In such cases, the sorting unit 13 may perform sorting using a machine learning model that has been trained in advance as described above, or may perform sorting based on temperature information of the crushed material.

[0030] For example, the sorting unit 13 may determine that the fragments are of a first type if their temperature is above a predetermined level, and that the fragments are of a second type if their temperature is below the predetermined level. In this example, the first type / second type fragments may be fragments of a magnetic material (iron material) / fragments of a mixture, fragments of a mixture / fragments of a non-magnetic material (aluminum material), or fragments of a magnetic material / fragments of a non-magnetic material. Three or more types of fragments may be distinguished. Fragments of any material may be used as long as they follow the trend of temperature change during application of a magnetic field. The temperature of the fragments used here may be, for example, the highest temperature in the infrared image, or any statistical value, such as the average or median of the temperature (brightness) of the fragments in the infrared image. The temperature threshold used here can be set arbitrarily depending on the type of fragments to be sorted, the strength and duration of the applied magnetic field, etc.

[0031] In conventional magnetic sorting processes, when separating magnetic and non-magnetic fragments, magnetic separation is performed to extract only the magnetic fragments. When performing magnetic separation on fragments containing iron and aluminum, a strong magnetic force attracts the iron portion, resulting in the fragments being sorted as iron. A weak magnetic force does not attract the iron portion, resulting in the fragments being sorted as aluminum. Here, if the fragments are separated as iron, their value as aluminum is lost, and if fragments containing iron as impurities are separated as aluminum, their quality as aluminum is reduced. On the other hand, the process using the sorting device 1 according to the present embodiment allows for inexpensive separation based on the amount of impurities contained in the fragments by referring to changes in the temperature information of the fragments due to the application of a magnetic field, without the need for expensive equipment such as X-rays.

[0032] 1 is an example. The transport unit 11 is not limited to this configuration as long as it is capable of transporting the crushed fragments, and may, for example, have an arm that grips and transports the crushed fragments instead of the belt conveyor 111. The functional units included in the information acquisition unit 12 are not limited to the optical image capture unit 12a and the infrared image capture unit 12b, and may, for example, include only the infrared image capture unit 12b, or there may be multiple capture units with the same function, and may include sensors (not shown) that acquire different information about the crushed fragments, such as an X-ray image capture unit that measures the thickness of the crushed fragments or a weight sensor that measures the weight of the crushed fragments.

[0033] The sorting process performed by the sorting device 1 according to this embodiment will be described below with reference to the flowchart in Fig. 3. Fig. 3 is a flowchart showing an example of the sorting process for crushed pieces performed by the sorting device 1. The process shown in Fig. 3 is performed by the control unit 14 controlling each functional unit. Furthermore, S301 to S306 in Fig. 3 are performed on a single crushed piece, and when crushed pieces are conveyed sequentially, each process can be performed on each of them.

[0034] In S301, the control unit 14 performs a preliminary sorting process to obtain crushed fragments to be processed, excluding those made of resin material, etc. Here, it is assumed that a pre-processing is performed using a known sorting process so that crushed fragments of iron material, crushed fragments of aluminum material, and crushed fragments of a mixture are the crushed fragments to be processed.

[0035] In S302, the control unit 14 controls the optical image capturing unit 12a to capture images of the fragments and acquire position information of the fragments. The position information acquired in S302 can be used to identify the fragments in each subsequent process or to determine the execution timing of each process.

[0036] In S303, the control unit 14 controls the magnetic field application unit 15 to apply a magnetic field to the crushed pieces. Here, for example, the control unit 14 can apply the magnetic field by exciting a magnetic field for a predetermined period (e.g., 10 milliseconds) when the crushed pieces pass over the magnetic field application unit 15, which is an electromagnetic induction coil arranged directly below the belt conveyor 111.

[0037] In S304, the control unit 14 controls the infrared image capturing unit 12b to acquire temperature information of the fragments. Here, infrared images of the fragments are acquired as temperature information, but multiple imaging devices for capturing infrared images may be prepared to capture infrared images at multiple timings, thereby acquiring changes in temperature distribution as described above.

[0038] In S305, the control unit 14 classifies the crushed pieces as described above based on the temperature information acquired in S304. Here, the control unit 14 can classify the crushed pieces as crushed pieces of iron material, crushed pieces of aluminum material, or crushed pieces of a mixture based on the temperature information.

[0039] In S306, the control unit 14 controls the sorting unit 13 to sort the crushed pieces according to the classification result in S305, and ends the processing in Fig. 3. As mentioned above, the processing described in S301 to S306 is processing for one crushed piece, and when crushed pieces are transported sequentially by the transport unit 11, S301 to S306 are executed for each of them.

[0040] This process allows a magnetic field to be applied to the metal product fragments while they are being transported, and the fragments can be sorted based on the temperature information of the fragments to which the magnetic field has been applied. This makes it possible to sort the fragments based on the temperature information corresponding to the application of the magnetic field, particularly whether they contain magnetic material that generates eddy currents when a magnetic field is applied, and provides an inexpensive device that sorts the fragments based on their material.

[0041] [Summary of the embodiment] The above embodiments disclose at least the following sorting device and sorting method.

[0042] 1. The sorting device of the above embodiment (for example, 1) A conveying unit (e.g., 11) for conveying crushed pieces of metal products; a magnetic field applying unit (e.g., 15) that applies a magnetic field to the fragments while the fragments are being transported; An acquisition unit (e.g., 12) that acquires temperature information of the fragments to which the magnetic field has been applied; A sorting unit (e.g., 13) that sorts the crushed pieces based on the temperature information; Equipped with. According to this embodiment, it is possible to sort the materials of the crushed pieces of metal products at a lower cost.

[0043] 2. In the sorting device of the above embodiment, the sorting unit classifies the fragments as either a first type of fragment or a second type of fragment based on the temperature information of the fragments, and sorts the fragments according to the results of the classification. According to this embodiment, it is possible to sort the fragments based on the temperature information.

[0044] 3. In the sorting device of the above embodiment, the first type of crushed fragments are crushed fragments of magnetic material, and the second type of crushed fragments are crushed fragments of non-magnetic material. According to this embodiment, it is possible to sort the fragments based on the difference in heat generation due to eddy currents.

[0045] 4. In the sorting device of the above embodiment, the first type of crushed fragments are crushed fragments of magnetic material, and the second type of crushed fragments are crushed fragments of a mixture of magnetic material and non-magnetic material. According to this embodiment, it is possible to sort the fragments based on the difference in heat generation due to eddy currents.

[0046] 5. In the sorting device of the above embodiment, the first type of crushed fragments are crushed fragments of a mixture of magnetic material and non-magnetic material, and the second type of crushed fragments are crushed fragments of non-magnetic material. According to this embodiment, it is possible to sort the fragments based on the difference in heat generation due to eddy currents.

[0047] 6. In the sorting device of the above embodiment, the magnetic field applying unit applies a magnetic field to the crushed pieces by an electromagnetic induction coil. According to this embodiment, it is possible to sort the crushed pieces inexpensively using an electromagnetic induction coil.

[0048] 7. In the sorting device of the above embodiment, the magnetic field applying unit applies a magnetic field from below the transport unit. According to this embodiment, it is possible to apply a magnetic field from below during transportation.

[0049] 8. In the sorting device of the above embodiment, the acquisition unit acquires an infrared image of the crushed pieces as the temperature information of the crushed pieces. According to this embodiment, the temperature change of the fragments can be evaluated by infrared images.

[0050] 9. In the sorting device of the above embodiment, the acquisition unit acquires an infrared image of the crushed pieces using an imaging unit that is provided above the transport unit and captures an infrared image. According to this embodiment, infrared images can be acquired from above during transport.

[0051] 10. In the sorting device of the above embodiment, the sorting unit distinguishes the fragments using a machine learning model that uses the infrared image as input and estimates the material of the fragments. According to this embodiment, it is possible to distinguish between fragments based on the characteristics of the temperature information according to the material of the fragments.

[0052] 11. The sorting process of the above embodiment is a conveying step of conveying the crushed pieces of the metal product; A magnetic field application step (e.g., S303) of applying a magnetic field to the crushed pieces while the crushed pieces are being transported; an acquisition step (S304) of acquiring temperature information of the fragments to which the magnetic field has been applied; a sorting step (S305, S306) of sorting the crushed pieces based on the temperature information; Equipped with. According to this embodiment, it is possible to sort the materials of the crushed pieces of the metal product at a lower cost.

[0053] Although the embodiments of the invention have been described above, the invention is not limited to the above-described embodiments, and various modifications and variations are possible within the scope of the gist of the invention. [Explanation of symbols]

[0054] 1: sorting device, 11: conveying unit, 12: information acquisition unit, 13: sorting unit, 14: control unit, 15: magnetic field application unit

Claims

1. a conveying unit that conveys crushed pieces of metal products; a magnetic field applying unit that applies a magnetic field to the fragments while the fragments are being transported; an acquisition unit that acquires temperature information of the fragments to which the magnetic field has been applied; a sorting unit that sorts the fragments based on the temperature information; A sorting device comprising:

2. The sorting device described in claim 1, characterized in that the sorting unit classifies the fragments as either a first type of fragment or a second type of fragment based on the temperature information of the fragments, and sorts the fragments according to the results of the classification.

3. 3. The sorting apparatus according to claim 2, wherein the first type of fragments are fragments of magnetic material, and the second type of fragments are fragments of non-magnetic material.

4. 3. The sorting device according to claim 2, wherein the first type of crushed fragments are crushed fragments of magnetic material, and the second type of crushed fragments are crushed fragments of a mixture of magnetic material and non-magnetic material.

5. 3. The sorting device according to claim 2, wherein the first type of crushed fragments are crushed fragments of a mixture of magnetic and non-magnetic materials, and the second type of crushed fragments are crushed fragments of non-magnetic materials.

6. 2. The sorting device according to claim 1, wherein the magnetic field applying unit applies a magnetic field to the crushed pieces by an electromagnetic induction coil.

7. The sorting device according to claim 6 , wherein the magnetic field applying unit applies the magnetic field from below the transport unit.

8. The sorting device according to claim 1 , wherein the acquisition unit acquires an infrared image of the crushed fragments as the temperature information of the crushed fragments.

9. The sorting device according to claim 8 , wherein the acquisition unit acquires an infrared image of the crushed pieces using an imaging unit that is provided above the transport unit and captures an infrared image.

10. The sorting device according to claim 8 , wherein the sorting unit distinguishes the fragments using a machine learning model that uses the infrared image as an input and estimates the material of the fragments.

11. a conveying step of conveying the crushed pieces of the metal product; a magnetic field application step of applying a magnetic field to the crushed pieces while the crushed pieces are being transported; an acquisition step of acquiring temperature information of the fragments to which the magnetic field has been applied; a sorting step of sorting the crushed pieces based on the temperature information; A selection method comprising:

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