Rotor magnet separation device, magnet separation and recovery device, and magnet separation method

Abstract

This invention aims to efficiently and efficiently process large quantities of magnets from motor rotors removed from end-of-life vehicles, while reducing the amount of work involved. [Solution] A device for recovering magnets from a rotor having multiple stacked steel plates and magnets fixed in holes in the steel plates, comprising a drum into which a demagnetized and resin-brittlemented rotor is fed and which is positioned horizontally, and a scraping plate provided on the inner surface of the drum, which scrapes up the rotor by rotating the drum along its axis and allows the rotor to fall from the top of the drum.

Description

Technical Field

[0001] The present invention relates to a magnet separation device, a magnet separation and recovery device, and a magnet separation method for separating magnets from a rotor such as a used automotive motor.

[0002] In recent years, the number of xEVs (electric vehicles) such as electric vehicles (EVs) and hybrid electric vehicles (HEVs) has been increasing. Large drive motors are installed in xEVs, and rare earth magnets with high procurement risks are widely used in the rotors, which are the rotors of these motors. Reliable recycling is required. With the high performance and high output of xEVs, the drive motors have become large and robust in structure, and the work load of disassembling and magnet recovery has been high and inefficient.

[0003] So far, a method has been generally used in which the rotor is heated at a high temperature to demagnetize the magnet and embrittle the magnet fixing resin, and after cooling the rotor to a workable temperature, vibration and impact are applied to the rotor and the magnet to separate and recover the magnet from the steel plate.

[0004] For example, in Patent Document 1, after heating and rapidly cooling the rotor, vibration is applied to the rotor by a magnet recovery device to recover the magnet. The magnet recovery device includes a horizontally arranged shaft and a vibrator that vibrates the shaft in the vertical direction. The shaft is passed through a through hole of the rotor core, and the rotor core is supported in a state where there is a sufficient gap between the outer peripheral surface of the shaft below the shaft and the inner peripheral surface of the rotor core. By vibrating the shaft in the vertical direction by the vibrator, vertical vibration is applied to the rotor core, and the outer peripheral surface of the shaft and the inner peripheral surface of the rotor core are continuously collided with each other.

[0005] Furthermore, Patent Document 2 discloses a method for discharging rare earth magnet material from the ends of a rotor by deforming the rotor after it has been separated from the motor component, thereby crushing the rare earth magnet material incorporated into the rotor. Specifically, this method uses a stirrer and a vibrating screen, and involves putting multiple rotors that have been heated, demagnetized, and air-cooled into the stirrer and stirring them to cause the inner wall of the stirrer and the rotors to collide with each other, thereby separating the magnets. After that, the separated magnets and steel plates are sorted and recovered using a vibrating screen. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2011-166966 [Patent Document 2] Japanese Patent Publication No. 2014-183617 [Overview of the project] [Problems that the invention aims to solve]

[0007] However, the method disclosed in Patent Document 1 is cumbersome to handle, as it involves passing each rotor onto the shaft individually, and the number of rotors that can be processed in a single vibration cycle is limited by the shaft length, making it unsuitable for mass processing. Furthermore, the method disclosed in Patent Document 2 may result in insufficient separation of magnets in modern large and robust motors due to the impact caused by stirring. Also, since magnet separation and sorting / recovery are performed by a stirrer and a vibrating screen respectively, it is necessary to install two devices, which results in the disadvantages of requiring space and high capital investment costs. While it is possible to recover magnets from rotors using the methods described in these patent documents, considering the increased processing volume due to the future proliferation of xEVs and the problem of securing workers due to the declining and aging workforce, there is a strong need to construct a system that can perform large-scale processing while reducing the workload and costs associated with magnet recovery.

[0008] This invention has been made in view of these circumstances, and aims to enable efficient and large-scale processing while reducing the amount of work involved in separating and recovering magnets from motor rotors removed from end-of-life automobiles and the like. [Means for solving the problem]

[0009] The present invention provides a rotor magnet separation device for separating magnets from a rotor having a plurality of stacked steel plates and magnets fixed in holes in the steel plates, The demagnetized and resin-brittlemented rotor is fed into a drum positioned horizontally, and the drum comprises a scraping plate provided on the inner surface of the drum, which scrapes up the rotor by rotating the drum along its axis and allows the rotor to fall from the top of the drum.

[0010] By rotating the horizontally oriented drum, the rotor inserted inside is scraped up at the bottom in the circumferential direction by a scraping plate, and after scraping up approximately half a rotation, it is dropped from the scraping plate at the top. This action is repeated. The impact of the drop effectively destroys the crimped parts between the steel plates and the resin fixing parts to the magnets, causing at least a portion of the rotor to separate from the steel plates, and the magnets inside to break, thus allowing at least a portion of them to be removed from the steel plates. By repeating this process, it becomes possible to separate and recover the magnets. The simple operation of loading the material into the drum and rotating it makes the work easy, and it is also possible to load multiple rotors into the drum and process them at once, making it ideal for large-scale processing. The drum can be positioned horizontally, and may be tilted slightly relative to the horizontal, not just horizontally. The drum can rotate automatically or manually.

[0011] In the rotor magnet separation device of the present invention, it is preferable that a floor plate for receiving the falling rotor is provided at a position 180° opposite to the scraping plate. When the rotor is heavy or the impact force from a fall is large, supporting the rotor with the floor plate instead of the inner surface of the drum protects the drum's perimeter and improves its durability.

[0012] In the rotor magnet separation device of the present invention, it is preferable that the inner diameter of the drum is 500 mm or more and 2000 mm or less. By using a drum with an inner diameter within this range, the rotor can be efficiently crushed by the impact of the fall. If the inner diameter of the drum is 500 mm or more, sufficient impact is ensured when the rotor falls, allowing the magnet to be separated in a short time. If it is 2000 mm or less, it is advantageous in terms of installation space and cost while keeping the drum size down.

[0013] In the rotor magnet separation device of the present invention, it is preferable to have a drive unit that rotates the drum along the axis.

[0014] The rotor magnet separation and recovery device of the present invention is a device for separating and recovering magnets from a rotor using the rotor magnet separation device, wherein a plurality of magnet recovery holes penetrating the peripheral wall of the drum are provided on the front side in the scraping direction by the scraping plate, between the scraping plate and the point where the rotor falls from the scraping plate.

[0015] After the rotor falls with the scraping plate positioned on top of the drum, the magnets can be dropped from the drum through the magnet retrieval holes and retrieved before being scraped up again by the scraping plate. This allows for efficient separation and retrieval of the magnets from the rotor simply by rotating the drum.

[0016] In the rotor magnet separation and recovery device of the present invention, a plurality of protrusions are provided further forward in the scraping direction than the region where the magnet recovery holes are formed, and are close to the region where the magnet recovery holes are formed, and it is preferable that the spacing between adjacent protrusions is set to a size that allows the magnets to pass through but prevents the steel plate from passing through.

[0017] By providing the aforementioned protrusions further forward in the scraping direction than the area where the magnet retrieval holes are formed, when the area where the magnet retrieval holes are formed is located at the bottom of the drum, the protrusions prevent the steel plate from sliding down into the area where the magnet retrieval holes are formed. This effectively guides only the magnets into the area where the magnet retrieval holes are formed, allowing the magnets to fall smoothly from the drum and be retrieved.

[0018] In the rotor magnet separation and recovery device of the present invention, it is preferable that a steel plate recovery opening is provided at a position opposite to the scraping direction by the scraping plate and close to the scraping plate, through the peripheral wall of the drum and through which the steel plate can pass.

[0019] By repeatedly raising and lowering the rotor due to the rotation of the drum, the steel plates and magnets are separated. Then, by rotating the drum in the reverse direction, the steel plates are dropped from the drum through the steel plate recovery opening, allowing the steel plates to be recovered separately from the magnets.

[0020] In the rotor magnet separation and recovery device of the present invention, a conveyor is provided below the drum, and the conveyor is preferably provided with a drive unit capable of driving it in both forward and reverse directions, a magnet recovery unit for recovering the magnets discharged from one end of the conveyor, and a steel plate recovery unit for recovering the steel plates discharged from the other end of the conveyor.

[0021] While the drum rotates forward, magnets are dropped through the magnet collection holes and transported to the magnet collection section by a conveyor. Once the magnet collection is complete, the drum is rotated in reverse, causing steel plates to drop onto the conveyor through the steel plate collection holes. The conveyor is then driven in the reverse direction to collect the steel plates in the steel plate collection section.

[0022] The method for separating magnets of the rotor of the present invention is a method for recovering the magnets from a rotor having a plurality of stacked steel plates and magnets fixed in the holes of the steel plates, comprising: putting the rotor into a horizontally placed drum, scraping up the rotor along the peripheral wall of the drum while rotating the drum, and dropping it at the upper part of the drum, and repeating this operation to separate the magnets from the rotor.

Effect of the Invention

[0023] According to the present invention, by rotating the drum, the operation of scraping up and dropping the rotor is repeated, whereby the steel plates are separated and the magnets are detached, and they can be separated. Separation can be achieved by a simple operation of putting the rotor into the drum and rotating it, reducing the amount of work while being efficient and enabling mass processing.

Brief Description of the Drawings

[0024] [Figure 1] It is a plan view showing an example of a rotor handled by a magnet recovery device according to an embodiment of the present invention. [Figure 2] It is a longitudinal sectional view taken along the line A-A of the rotor in FIG. 1. [Figure 3] It is a configuration diagram of a magnet separation and recovery system according to an embodiment. [Figure 4] It is a front view showing a magnet separation and recovery device according to an embodiment. [Figure 5] It is a side view of the magnet separation and recovery device in FIG. 4. [Figure 6] It is an enlarged view of the scraping plate in FIG. 4, and (b) is a right side view of (a). [Figure 7] It is a cross-sectional view showing the action of the scraping plate in the drum in FIG. 4 in the order from (a) to (b). [Figure 8] It is a flowchart showing a magnet separation and recovery method according to an embodiment. [Figure 9] Regarding the action of the protrusion with respect to the magnet recovery hole in FIG. 4, (a) is a cross-sectional view and (b) is a top view of the vicinity of the magnet recovery hole in the drum. [Figure 10]A front view showing a magnet separation and recovery device according to another embodiment of the present invention. [Figure 11] Figure 10 is a side view of the magnet separation and recovery device. [Modes for carrying out the invention]

[0025] Embodiments of the present invention will be described below with reference to the drawings. First, let's explain the rotor. As shown in Figures 1 and 2, the rotor 1 is formed in a cylindrical shape overall by joining multiple annularly shaped magnetic steel plates 2 in a laminated state by crimping or the like. A central hole 3 is formed in the center to which an axis (not shown) is fixed. In addition, multiple holes 4 are formed in each steel plate 2 at intervals in the circumferential direction, and the steel plates 2 are laminated with each hole 4 communicating in the axial direction. In other words, each hole 4 in the axially communicating state is formed to be the same size in each steel plate 2, and the laminated steel plates 2 form one long, straight magnet insertion hole 4. A magnet 5 is then fixed in this communicating magnet insertion hole 4 by a magnet fixing resin 6.

[0026] For the steel plate 2, for example, a silicon steel plate with a thickness of 0.35 mm is used, for the magnet 5, for example, a rare earth magnet such as neodymium is used, and for the magnet fixing resin 6, epoxy resin is preferably used. The dimensions of rotor 1 are not particularly limited, but for example, the diameter is 130 mm to 250 mm and the length (height of the stacked steel plates 2) is 50 mm to 150 mm.

[0027] A magnetic separation and recovery system 10 according to one embodiment of the present invention will be described. As shown in Figure 3, this magnet separation and recovery system 10 includes a heating device 11 for heating the rotor 1, a cooling device 12 for slowly cooling the rotor 1 heated by the heating device 11, and a separation and recovery device 13 for separating the magnet and steel plate from the cooled rotor 1 and recovering the separated magnet and steel plate.

[0028] A heating furnace (not shown) is used as the heating device 11, and the rotor is heated to a temperature above the higher of the Curie temperature or the embrittlement temperature of the magnet fixing resin, thereby demagnetizing the magnet 5 in the rotor 1 and embrittlement of the magnet fixing resin 6.

[0029] As the cooling device 12, a slow cooling method is used. For example, the heated rotor 1 is placed on a cooling stand (not shown) on a pallet and left in a room at room temperature. Multiple cooling stands are used to allow many rotors 1 to be cooled. In this case, it is preferable to space the rotors 1 apart as much as possible so that the surface of each rotor 1 is in contact with the air as much as possible.

[0030] As a method of slow cooling, the heated rotor 1 can be placed on a cooling stand and allowed to cool naturally. However, a cooling device 12 may be provided with a blower and a refrigerant sprayer (neither of which are shown), and methods such as blowing air onto the rotor 1 with the blower or spraying refrigerant onto the rotor 1 with the sprayer and utilizing the heat of vaporization may also be used in combination. If the cooling method is rapid cooling, the steel plate 2 may undergo plastic deformation, impairing the straightness of the magnet insertion hole 4, and making it difficult to remove the magnet 5 from the deformed magnet insertion hole 4. For this reason, in this embodiment, slow cooling is used to prevent plastic deformation of the steel plate 2, and cooling may be accelerated by refrigerant spraying or the like to the extent that plastic deformation of the steel plate 2 does not occur (to the extent that it is not rapid cooling).

[0031] In this embodiment, the separation and recovery device 13 includes a separation means 14 for separating the steel plate 2 and magnet 5 from the rotor 1, which has been demagnetized and the resin embrittlemented by heating and cooling, and a recovery means 15 for recovering the separated steel plate 2 and magnet 5, respectively. This separation and recovery device 13 separates the steel plate 2 and magnet 5 by inserting the rotor 1 into the drum 21 and applying impact while rotating it, and recovers them. As shown in Figures 4 and 5, the separation means 14 includes the drum 21 and its drive unit 22, etc., and the recovery means 15 includes a hopper, recovery container, etc., which will be described later.

[0032] The drum 21 is not necessarily limited, but the inner diameter of the cylindrical peripheral wall 25 is formed to be, for example, 500 mm or more and 2000 mm or less. The axis of the peripheral wall 25 is located along the horizontal direction, and a rotor insertion opening 26 is provided on one end face. The other end face of the peripheral wall 25 is closed.

[0033] The drum 21 is mounted on a frame 31, with two horizontal rollers 32 arranged parallel to each other and spaced apart, so that the outer surface of the peripheral wall 25 is supported on the rollers 32. At least the outer circumference of these rollers 32 is made of an elastomer such as urethane, so that a suitable frictional force acts between them and the outer surface of the peripheral wall 25 of the drum 21. A drive unit 22 is provided on one of the rollers 32 to rotate the roller 32, and as the roller 32 rotates, the peripheral wall 25 of the drum 21 is rotated along its axis by the frictional force with the roller 32.

[0034] In the illustrated example, the drive unit 22 is composed of a motor 33 and a transmission mechanism 34 such as a belt that transmits the rotational force of the motor 33 to the roller 32. However, other general-purpose drive units, such as a transmission mechanism using a motor and gears, may also be used. The rotation direction of the drum 21 can be either forward (counterclockwise, as indicated by the arrow in Figure 4) or reverse (clockwise) by reversing the forward and reverse rotation of the motor 33 or by rearranging the transmission mechanism. In the following, forward rotation (counterclockwise, as indicated by the arrow in Figure 4) will be considered the normal state, and with respect to this normal rotation direction, the front side along the circumferential direction of the drum 21 will be considered the upstream side, and the rear side will be considered the downstream side.

[0035] Furthermore, a scraping plate 41 is provided on the inner surface of the peripheral wall 25 of the drum 21. This scraping plate 41 is formed, for example, in a rectangular shape, and one side of it is fixed along the length direction to the inner surface of the peripheral wall 25 of the drum 21. In the illustrated example, the scraping plate 41 is mounted on a base plate 42 fixed to the peripheral wall 25 of the drum 21. In this case, the scraping plate 41 is provided at an inclination with respect to the radial direction of the drum 21, and in its mounting position, it protrudes from a height of about 1 / 3 of the radius of the drum 21 to the vicinity of the rotor input opening 26. When the drum 21 is rotating normally (counterclockwise rotation as indicated by the arrow in Figure 4), the free end 41a of the scraping plate 41 is directed forward (upstream) in the direction of rotation of the drum 21. For this reason, when rotating normally, the rotor 1 is positioned in the triangular prism-shaped space 43 between the peripheral wall 25 and the scraping plate 41 and scraped up.

[0036] Furthermore, on the inner circumference (drop point) of the peripheral wall 25 180° opposite to the scraping plate 41, a floor plate 45 is provided to receive the rotor 1 when the scraping plate 41 reaches the top of the drum 21 and the rotor 1 falls. This floor plate 45 has sufficient strength to prevent deformation from occurring when the rotor 1 falls. In the example shown in Figure 4, when the scraping plate 41 is positioned on the top of the drum 21, the floor plate 45 is positioned diagonally with respect to the horizontal direction, so that the rotor 1 falling from the scraping plate 41 collides with the diagonal floor plate 45, thereby applying a strong impact force. Because this floor plate 45 is provided, the impact force of the fall is not directly transmitted to the peripheral wall 25, which is advantageous in terms of the strength design of the peripheral wall 25.

[0037] Furthermore, as shown in Figure 9, the scraping plate 41 is provided with a baffle plate 46 that rises from the surface of the scraping plate 41 on the rotor input opening 26 side of the drum 21, so as to prevent the steel plates 2 and magnets 5 of the rotor 1 that are scraped up by the scraping plate 41 from leaking out of the rotor input opening 26 from the scraping plate 41 while the drum 21 is rotating.

[0038] Furthermore, the peripheral wall 25 of the drum 21 is provided with multiple magnet retrieval holes 47 that penetrate the peripheral wall 25, on the forward side in the direction of scraping by the scraping plate 41, that is, upstream of the scraping plate 41 in the rotational direction. Specifically, when the rotor 1 is scraped up by the scraping plate 41, the rotor 1, steel plate 2, and magnet 5 are stored together in the aforementioned triangular prism-shaped cavity 43 of the scraping plate 41, and the magnet retrieval holes 47 are provided slightly upstream of the area where this mass is placed. These magnet retrieval holes 47 are formed to be large enough for the magnet 5 to pass through, but not large enough for the rotor 1, its partial mass, or the steel plate 2 to pass through. Their purpose is to allow the magnet 5 that has fallen from the scraping plate 41 and detached from the rotor 1 due to impact with the floor plate 45 to pass through and fall from the drum 21, and multiple such holes are provided, dispersed in a specific magnet retrieval hole forming region 48.

[0039] Furthermore, on the inner surface of the peripheral wall 25 further forward in the scraping direction (upstream in the rotation direction) than the magnet recovery hole forming region 48, multiple rod-shaped protrusions 49 are provided along the radial direction. These protrusions 49 are fixed in a row along the length of the peripheral wall 25, and the spacing along the length of the peripheral wall 25 is set to be smaller than the diameter of the steel plate 2 so that the rotor 1, its partial mass, and the steel plate 2 cannot pass between the protrusions 49.

[0040] When the steel plate 2 is placed simultaneously with the magnet 5 that has detached from the rotor 1 on the magnet retrieval hole 47 forming area 48, the magnet 5 may be placed on top of the steel plate 2 and not fall through the magnet retrieval hole 47. However, when the drum 21 is rotated and the magnet retrieval hole 47 forming area 48 is positioned at the bottom of the drum 21, the projection 49 is positioned to protrude upstream of the magnet retrieval hole forming area 48. As shown in Figure 7, the steel plate 2 and the like are caught on the projection 49, preventing them from sliding down into the magnet retrieval hole forming area 48, and only the magnet 5 slides down into the magnet retrieval hole forming area 48 from between the projections 49. Therefore, the steel plate 2 and the like do not block the magnet retrieval hole 47, and the magnet 5 can fall smoothly through the magnet retrieval hole 47.

[0041] However, although the height of the projection 49 is greater than the total thickness of the steel plates 2 when they are stacked on top of each other, as the drum 21 rotates, the area 48 where the magnet recovery hole 47 is formed moves from directly below the drum 21, and the projection 49 is formed low enough that the rotor 1, its partial mass, and the steel plates 2 that were caught on it can fall over the projection 49. As a result, when the steel plates 2 are lifted to a certain height by the projection 49, they fall downward and are then scraped up by the scraping plate 41.

[0042] On the other hand, on the opposite side of the scraping direction from the scraping plate 41 (downstream of the drum 21 in the rotation direction from the scraping plate 41), a steel plate recovery opening 51 is formed close to the scraping plate 41. This steel plate recovery opening 51 is a single large opening set to a size that allows the steel plate 2 to pass through. Because this steel plate recovery opening 51 is located downstream of the scraping plate 41, during normal rotation, the rotor 1 and steel plate 2 are scraped up by the scraping plate 41, fall over the top of the drum 21, and then scraped up again by the scraping plate 41, and this operation is repeated, so the steel plate 2 is never placed in the steel plate recovery opening 51.

[0043] Below the drum 21, a hopper 55 is provided, supported by a frame 31. Below the hopper 55, a recovery container 56 is provided, and the magnets 5 that fall from the magnet recovery holes 47 of the drum 21 are stored in the recovery container 56 via the hopper 55. Once the recovery of the magnets 5 is complete, multiple steel plates 2 will be arranged separately inside the drum 21. For this reason, the steel plates 2 can be removed directly from the drum 21, but if the recovery container 56 below the hopper 55 is replaced with a recovery container for steel plates (not shown), and the drum 21 is rotated in the reverse direction, the steel plate recovery opening 51, which was formed behind the scraping plate 41, is positioned at the bottom of the drum 21, and the steel plates 2 fall from this opening 51 and are stored in the recovery container from the hopper 55.

[0044] In the separation and recovery device 13 configured in this way, the separation means 14 is composed of a drum 21 and its drive unit 22, etc., and the recovery means 15 is composed of a magnet recovery means consisting of a magnet recovery hole 47 in the drum 21, a hopper 55 and a recovery container 56, and a steel plate recovery means consisting of a steel plate recovery opening 51 in the drum 21, a hopper 55 and a steel plate recovery container.

[0045] A method for separating and recovering the magnet 5 from the rotor 1 using the magnet separation and recovery system 10 configured as described above will now be explained. As shown in Figure 8, this magnet separation and recovery method (separation method and recovery method) includes a heating step in which the rotor 1 is heated by a heating device 11 to demagnetize the magnet 5 and embrittle the magnet fixing resin 6; a cooling step in which the rotor 1 is cooled by a cooling device 12 after the heating step; and a separation and recovery step in which the magnet and steel plate are separated from the cooled rotor 1 by a separation and recovery device 13, and the separated magnet and steel plate are recovered. The following explains the process step by step.

[0046] [Heating process] In the heating process, as mentioned above, the rotor 1 is heated to a temperature higher than the Curie temperature or the embrittlement temperature of the magnet fixing resin, whichever is higher. For neodymium magnets, demagnetization occurs by holding them at a temperature of 380°C or higher (330°C to 380°C) for about 15 minutes. Regarding the embrittlement of the magnet fixing resin, although it depends on the type of resin, decomposition and embrittlement usually progress when heated to a temperature higher than the Curie temperature of the magnet. Therefore, the temperature should be set to promote the demagnetization of the magnet 5 and the embrittlement of the magnet fixing resin 6.

[0047] [Cooling process] In the cooling process, the rotor 1, which has become hot during the heating process, is placed on a pallet or the like and left in the air to cool slowly. For example, after the heating process is completed, it may be stored for, say, one day. In conventional methods, a rapid cooling process must be carried out immediately after the heating process. Furthermore, since the rotor 1 must be immersed in the water tank in a short time after the heating process, it is necessary to ensure a connection from the heating furnace to the water tank, making the work complicated. However, in this embodiment, cooling can be achieved simply by leaving it unattended, making the work easy.

[0048] When recovering multiple rotors 1, the process involves sequentially heating the rotors 1 in the heating step and then arranging and placing them on a pallet or the like, repeating this process. The heating and cooling steps can be performed sequentially, separate from the subsequent recovery step. Furthermore, since the next recovery process can be performed on the rotor 1 that has been left unattended, the resting time for slow cooling after the heating process can be used as a buffer period, thereby improving work efficiency.

[0049] Furthermore, if it does not cause rapid cooling, air may be blown onto the rotor 1 using a blower. Alternatively, water or other liquids may be dispersed into a fine mist from a sprayer and applied to the rotor 1.

[0050] [Separation and Recovery Process] In this embodiment, the separation and recovery process is carried out by inserting the rotor 1 after the cooling process into the drum 21 of the separation and recovery device 13 through the rotor input opening 26 of the drum 21, and separating the magnet 5 and steel plate 2 while rotating the drum 21 (separation process), recovering the separated magnet 5 (magnet recovery process), and further recovering the steel plate 2 separately after recovering the magnet 5 (steel plate recovery process).

[0051] As shown in Figures 7(a) and 7(b), the rotor 1, once placed inside the drum 21, is scraped up by the scraping plate 41 protruding from the inner surface of the peripheral wall 25, slides off the scraping plate 41 at the top of the drum 21, and falls, colliding with the floor plate 45 at the bottom. Since the rotor 1 has been demagnetized and the fixing resin has been embrittlemented in the previous heating process, the impact of the collision with the floor plate 45 causes the magnet fixing resin 6, which was embrittlemented in the previous process, to collapse, and at least a portion of it separates into multiple lumps. Alternatively, a portion of the steel plate 2 separates individually, the internal magnet 5 is no longer restrained and the magnet 5 comes out, or the magnet 5 breaks and detaches.

[0052] As the drum 21 continues to rotate, the rotor 1 is repeatedly lifted by the scraping plate 41, falls from the top of the drum 21, and collides with the floor plate 45. The rotor 1 that has fallen to the bottom of the drum 21 remains there, sliding along the peripheral wall 25 of the drum 21 until it is scraped up again by the scraping plate 41. As the drum 21 rotates, vibrations are applied to the rotor 1 by the peripheral wall 25. Due to the repeated impacts from falling from the scraping plate 41 and the vibrations applied to the inner surface of the drum 21, the rotor 1 gradually separates into individual steel plates 2, and the internal magnets 5 are no longer restrained and fall out, or the magnets 5 break and detach.

[0053] As the drum 21 rotates, after falling from the scooping plate 41, the steel plate 2 and magnet 5, as described above, slide along the inner surface of the peripheral wall 25 of the rotating drum 21 and remain at the bottom of the drum 21. When the projection 49, which is located in front of the magnet retrieval hole forming area 48, is positioned at the bottom of the drum 21, as shown in Figure 7, the steel plate 2 gets caught on the projection 49 and is scooped up in the circumferential direction of the drum 21, while the magnet 5 slides down from between the projections 49 and falls to the bottom of the drum 21 via the magnet retrieval hole 47.

[0054] (Magnet recovery process) Below the drum 21, a magnet recovery container (magnet recovery section) 56 is provided below the hopper 55, and the magnets 5 that fall from the magnet recovery holes 47 of the drum 21 are stored in the magnet recovery container 56 via the hopper 55. In this case, as mentioned above, the steel plate 2 is blocked by the projection 49 to prevent it from sliding into the magnet recovery hole forming area 48, so that only the magnets 5 can be recovered by falling from the magnet recovery holes 47.

[0055] (Steel plate recovery process) Once the magnets 5 have been collected into the magnet collection container 56 while the drum 21 is rotating in this manner, the magnet collection container 56 is replaced with an empty steel plate collection container (not shown) and placed below the hopper 55. Then, when the drum 21 is rotated in the opposite direction to when the magnets were collected (clockwise in Figure 4), the steel plate collection opening 51, which is formed in the peripheral wall 25 on the opposite side of the scraping plate 41 from the void 43 created by the scraping plate 41, is positioned below the drum 21. At this point, the steel plates 2 fall through this steel plate collection opening 51 and are stored in the steel plate collection container via the hopper 55.

[0056] As described above, by using this separation and recovery device 13, the steel plate 2 and magnet 5 can be efficiently separated from the rotor 1 simply by rotating the drum 21, and they can be reliably recovered separately without mixing. Moreover, by simply changing the rotation direction of the drum 21, the recovery of the magnet 5 and the steel plate 2 can be performed separately, and the separation and recovery can be performed efficiently with almost no manual intervention. The device is simple and easy to operate, making it suitable for large-scale processing.

[0057] Furthermore, by using slow cooling instead of rapid cooling, equipment such as water tanks is unnecessary, plastic deformation of the steel plate 2 due to rapid cooling is suppressed, and corrosion such as rust caused by the use of water is eliminated, eliminating the need for wastewater and residue treatment. In addition, since the slow cooling method only requires leaving it unattended, the work is easy, and by carrying out the separation and recovery process after temporary storage for slow cooling following the heating process, the temporary storage time can be used as a buffer time, improving work efficiency and thereby shortening the work time.

[0058] In the embodiment described above, a collection container for the magnet or steel plate was installed below the hopper 55 to collect the magnet 5 and the steel plate 2 separately. However, a conveyor device 62 may also be provided, as shown in the separation and collection device 61 in Figures 10 and 11.

[0059] This conveyor device 62 is installed below the frame 31 that supports the drum 21 in the separation and recovery device 13 of one embodiment, with the lower part of the drum 21 being the middle part in the longitudinal direction, and includes a conveyor belt 63 and pulleys 64 and 65 arranged at both ends thereof, and a drive unit 66 that drives one of these pulleys 64 and 65. The conveyor belt 63 is provided so that the central part in the width direction is recessed, and is provided with a plurality of carrier rollers 67 that maintain this recessed state. Furthermore, recovery containers 68 and 69 for storing the magnets 5 or steel plates 2 conveyed by the conveyor belt 63 are provided at both ends of the conveyor belt 63. The recovery container 68 provided at one end of the conveyor belt 63 is for magnets, and the recovery container 69 provided at the other end is for steel plates.

[0060] In the separation and recovery device 61 of this embodiment, the separation means 14 is the same as in the first embodiment, but the recovery means 15 (denoted by the same reference numerals as in the first embodiment) is composed of a hopper 55 and a conveyor device 62, etc.

[0061] Because the conveyor device 62 is located below the drum 21, when the drum 21 rotates, the magnets 5 separated from the rotor 1 fall onto the conveyor belt 63 via the hopper 55. The conveyor device 62 is driven continuously when the drum 21 is rotating, or as needed, such as when a predetermined amount of magnets 5 have accumulated on the conveyor belt 63, to transport the fallen magnets 5 and store them in the magnet collection container 68.

[0062] In this case, the drive unit 66 is configured to collect the magnets 5 into the magnet collection container 68 by driving the conveyor belt 63 in one direction, and to collect the steel plates 2 into the steel plate collection container 69 by driving it in the opposite direction (other direction). Therefore, when the drum 21 is rotating to separate the magnets 5, it is driven so that the magnets 5 that have fallen onto the conveyor belt 63 can be collected into the magnet collection container 68. After the collection of the magnets 5 is completed, the drum 21 is rotated in the opposite direction, and when the steel plates 2 fall from the steel plate collection opening 51, they should be collected from the conveyor belt 63 into the steel plate collection container 69.

[0063] Although embodiments of the present invention have been described above, the present invention is not limited thereto and can be modified as appropriate without departing from the technical spirit of the invention. The magnet separation device of the present invention only needs to be able to separate the magnet from the rotor, and only needs to have at least the separation means of each embodiment. Furthermore, the magnet recovery device of the present invention only needs to be able to recover at least the magnets from the steel plates and magnets that constitute the rotor, and may consist only of magnet recovery holes provided in the peripheral wall of the drum. In that case, the steel plates can be removed from the drum after the magnets have been recovered. Furthermore, while an example was shown in which a belt conveyor was installed to collect the magnets and steel plates falling from the drum, magnets and other materials could also be collected by connecting a chute to the hopper.

[0064] Furthermore, although the drum was rotated by a drive unit, it could also be rotated manually. While the dimensions of the drum are not limited to the embodiment, if the inner diameter of the drum is 500 mm or more, sufficient impact is ensured when the rotor falls, allowing the magnet to be separated in a short time. If it is 2000 mm or less, the drum size is kept down, which is advantageous in terms of installation space and cost. For this reason, an inner diameter of 500 mm to 2000 mm is preferable in terms of balancing these factors. Furthermore, although the axis of this drum is positioned horizontally, it may also be positioned at a slight incline relative to the horizontal direction, as long as the drum as a whole is oriented horizontally. In addition, although a baffle plate is provided on the scraping plate, a lid, shutter, curtain, etc. that can be opened and closed may be provided on the rotor insertion opening. [Explanation of Symbols]

[0065] 1 rotor 2 steel plate 3 central hole 4 holes (magnet insertion holes) 5 Magnets 6. Resin for fixing magnets 10. Magnetic Separation and Recovery System 11 Heating device 12 Cooling device 13 Separation and Recovery Device 14 Separation means 15. Recovery methods 21 Drums 22 Drive unit 25 Peripheral wall 26 Rotor insertion opening 31. Stand 32 Laura 33 Motor 34 Transmission Mechanism 41. Scraping board 41a Free end 42 Base plate 43 Blank 45 floorboards 46 Obstacle board 47 Magnet recovery hole 48 Area for forming holes for magnet retrieval 49 Protrusion 51. Opening for steel plate recovery 55 Hoppa 56 Magnet collection container (magnet collection section) 61 Separation and recovery device 62 Conveyor device 63 Conveyor belt 64, 65 Pulley 66 Drive unit 67 Carrier Roller 68 Magnet collection container (magnet collection section) 69 Steel plate recovery container (steel plate recovery section)

Claims

1. A device for separating a magnet from a rotor having multiple stacked steel plates and magnets fixed in holes in the steel plates, A rotor magnet separation device characterized by comprising: a drum into which a demagnetized and resin-brittlemented rotor is inserted and which is positioned horizontally; and a scraping plate provided on the inner circumferential surface of the drum, which scrapes up the rotor by rotating the drum along its axis, and separates the magnet from the rotor by the impact of the fall at the bottom of the drum when the rotor is dropped from the top of the drum.

2. The rotor magnet separation device according to claim 1, characterized in that a floor plate for receiving the falling rotor is provided at a position 180° opposite to the aforementioned scraping plate.

3. The rotor magnet separation device according to claim 1, characterized in that the inner diameter of the drum is 500 mm or more and 2000 mm or less.

4. The rotor magnet separation device according to claim 1, characterized in that it has a drive unit that rotates the drum along the axis.

5. A device for separating and recovering the magnets from a rotor using a rotor magnet separation device according to any one of claims 1 to 4, A rotor magnet separation and recovery device characterized in that a plurality of magnet recovery holes are provided on the front side in the scraping direction by the scraping plate, between the scraping plate and the point where the rotor falls from the scraping plate, and these holes penetrate the peripheral wall of the drum.

6. The rotor magnet separation and recovery device according to claim 5, wherein a plurality of protrusions are provided further forward in the scraping direction than the area where the magnet recovery holes are formed, and are close to the area where the magnet recovery holes are formed, and the spacing between adjacent protrusions is set to a size that allows the magnet to pass through but prevents the steel plate from passing through.

7. The rotor magnet separation and recovery device according to claim 5, characterized in that a steel plate recovery opening is provided in the peripheral wall of the drum and through which the steel plate can pass, at a position on the opposite side of the scraping direction by the scraping plate and in close proximity to the scraping plate.

8. The rotor magnet separation and recovery device according to claim 5, characterized in that a conveyor is provided below the drum, and the conveyor is provided with a drive unit capable of driving it in both forward and reverse directions, a magnet recovery unit for recovering the magnets discharged from one end of the conveyor, and a steel plate recovery unit for recovering the steel plates discharged from the other end of the conveyor.

9. A method for recovering magnets from a rotor having multiple stacked steel plates and magnets fixed in holes in the steel plates, characterized in that the rotor is placed in a horizontal drum, the drum is rotated while the rotor is scraped up along the peripheral wall of the drum, and the operation of dropping the rotor at the top of the drum is repeated, thereby separating the magnets from the rotor by the impact of dropping at the bottom of the drum.

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