Manufacturing method of rare earth-based sintered magnet

Abstract

To provide a manufacturing method of a rare earth-based sintered magnet capable of executing the step of simultaneously applying processing to a plurality of workpieces in different shapes and sizes.SOLUTION: A manufacturing method of a rare earth-based magnet includes the steps of: simultaneously applying processing to a plurality of workpieces including a plurality of first workpieces and a plurality of second workpieces in a smaller size than the plurality of first workpieces; and supplying the plurality of processed workpieces to a part feeder and separating the plurality of first workpieces and the plurality of second workpieces from the part feeder. The part feeder comprises: a conveyance path for conveying the plurality of workpieces; and a guide member disposed at one side of the conveyance path. The conveyance path is tilted in such a manner that the side where the guide member is disposed becomes relatively low, and includes an opening in such a size through which the plurality of first workpieces can be passed and the plurality of second workpieces cannot be passed during the conveyance.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a method for producing a rare earth sintered magnet. [Background technology]

[0002] In the manufacturing field of rare earth sintered magnets such as RTB sintered magnets (R is a rare earth element, T is Fe or Fe and Co, and B is boron), a wide variety of products with different shapes and dimensions can be produced in the same factory. Even for the same type of product, the shape and dimensions of the rare earth sintered magnet (hereinafter sometimes referred to as the "workpiece") change in various ways at each stage of the manufacturing process due to mechanical processing and the like. Compared to mechanical parts such as screws that are mass-produced according to standards, or electronic parts such as semiconductor chips, rare earth sintered magnets have a high degree of freedom in the shape and dimensions of the workpiece, and handling and transportation in the manufacturing process require handling that matches the shape and dimensions of the workpiece.

[0003] Regarding the transportation of mechanical parts, for example, Patent Document 1 describes a parts feeder that selects nut parts of different sizes. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Utility Model Application Publication No. 57-95284 Summary of the Invention [Problem to be solved by the invention]

[0005] During the manufacturing process of rare earth sintered magnets, the workpieces that have been mechanically processed, such as cut or polished, are subjected to a cleaning process to remove grinding sludge and grinding fluid. Conventionally, when mechanically processing a workpiece (first variety) belonging to a first group having a certain shape and dimensions and a workpiece (second variety) belonging to a second group having another shape and dimensions, the machining process was often performed at different locations using different processing devices for each group. In that case, the workpieces belonging to the first group and the workpieces belonging to the second group are cleaned by different cleaning devices, or are cleaned by group at different times by the same cleaning device. The reason for this is that if different types of workpieces are put into one cleaning device at the same time to perform the cleaning process, the different types of workpieces will be mixed during the cleaning process. Conventionally, when manufacturing rare earth sintered magnets, the process flow has been determined so that different types of workpieces will not be mixed during the manufacturing process.

[0006] An embodiment of the present disclosure provides a method for producing a rare earth sintered magnet, which includes a process for simultaneously processing a plurality of workpieces having different shapes and sizes. [Means for solving the problem]

[0007] In one embodiment, a method for producing a rare earth sintered magnet according to the present disclosure includes the steps of simultaneously processing a plurality of workpieces, including a plurality of first workpieces and a plurality of second workpieces each smaller in size than each of the plurality of first workpieces, and supplying the plurality of workpieces that have been processed to a parts feeder and separating the plurality of first workpieces and the plurality of second workpieces from the parts feeder. The parts feeder includes a transport path for transporting the plurality of workpieces and a guide member disposed on one side of the transport path. The transport path is inclined so that the side on which the guide member is disposed is relatively lower, and has an opening that is large enough to allow each of the plurality of first workpieces to pass through while not allowing each of the plurality of second workpieces to pass through during transport. Effect of the Invention

[0008] According to the embodiment of the rare earth sintered magnet of the present disclosure, it is possible to carry out a process of simultaneously processing a plurality of workpieces having different shapes and sizes. [Brief description of the drawings]

[0009] [Figure 1] FIG. 2 is a schematic top view illustrating an example of a conveying step in the embodiment of the method for producing a rare earth sintered magnet according to the present disclosure. [Diagram 2] 4A to 4C are perspective views showing schematic examples of shapes and sizes of a first workpiece and a second workpiece. [Diagram 3] FIG. 1 is a top view illustrating a schematic configuration example of a mixed cleaning system that can be used in an embodiment of the present disclosure. [Figure 4] FIG. 2 is a top view showing a schematic diagram of a part feeder included in the mixed cleaning system. [Figure 5A] 5 is a schematic diagram showing a cross section of the part feeder taken along line AA in FIG. 4. [Figure 5B] 5 is an enlarged schematic diagram showing a cross section of the part feeder taken along line BB in FIG. 4. [Figure 6] 2 is an enlarged top view showing a planar configuration of a conveying path in the part feeder according to the embodiment of the present disclosure. FIG. [Figure 7] FIG. 4 is a top view showing a schematic diagram of a first workpiece moving on a transport path in the part feeder. [Figure 8] FIG. 11 is a top view showing a schematic view of a second workpiece moving on a transport path in the part feeder. [Figure 9A] 4 is a cross-sectional view showing a schematic diagram of a first workpiece moving on a transport path in the part feeder. FIG. [Figure 9B] 11 is a cross-sectional view showing a schematic view of a second workpiece moving on a transport path in the part feeder. FIG. [Figure 10A] FIG. 11 is a cross-sectional view showing a schematic diagram of a conveying path in another example of the parts feeder. [Figure 10B] FIG. 11 is a cross-sectional view showing a schematic view of a first workpiece moving on a transport path in another example of the part feeder. [Figure 10C] FIG. 11 is a cross-sectional view showing a schematic view of a second workpiece moving on a transport path in another example of the part feeder. [Figure 11] 13 is an enlarged top view showing a planar configuration of still another conveying path in the part feeder according to the embodiment of the present disclosure. FIG. [Figure 12] 13 is an enlarged top view showing a planar configuration of still another conveying path in the part feeder according to the embodiment of the present disclosure. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] As shown in FIG. 1, an embodiment of a method for manufacturing a rare earth sintered magnet according to the present disclosure includes a step (S10) of simultaneously processing a plurality of workpieces 10, 20 including a plurality of first workpieces 10 and a plurality of second workpieces 20 smaller in size than each of the plurality of first workpieces 10, and a step (S20) of supplying the processed plurality of workpieces 10, 20 to a part feeder 200 and separating the plurality of first workpieces 10 and the plurality of second workpieces 20 from the part feeder 200.

[0011] 2, each of the first workpieces 10 and the second workpieces 20 in this embodiment is generally a rectangular parallelepiped and has a rectangular shape when viewed from above. The workpieces 10 and 20 in this embodiment are sintered bodies of rare earth alloy powder in the process of being manufactured.

[0012] The size of each workpiece 10 is defined by a length 10L, a width 10W, and a thickness 10T, and the size of each workpiece 20 is defined by a length 20L, a width 20W, and a thickness 20T. In this embodiment, the length 10L of the workpiece 10 is longer than the length 20L of the workpiece 20, and the width 10W of the workpiece is longer than the width 20W of the workpiece 20. The thickness 10T of the workpiece 10 is thicker than the thickness 20T of the workpiece 20, but may be equal to or smaller than the thickness 20T of the workpiece 20. For example, when the width 10W of the workpiece 10 is 10 mm or more and 20 mm or less, the width 20W of the workpiece 20 may be 6 mm or more and 12 mm or less. From the viewpoint of ease of separation in the step (S20), the width 20W of the workpiece 20 is preferably 70% or less of the width 10W of the workpiece 10. Moreover, when the length 10L of the workpiece 10 is 30 mm or more and 60 mm or less, the length 20L of the workpiece 20 may be 20 mm or more and 40 mm or less. The length 20L of the workpiece 20 is preferably 70% or less of the length 10L of the workpiece 10.

[0013] The shapes of the first workpiece 10 and the second workpiece are not limited to a rectangular parallelepiped, and may be a bow shape, a semi-cylindrical shape, or a ring shape (ring shape).

[0014] The step (S10) of simultaneously processing a plurality of workpieces 10, 20 is, for example, a cleaning step or a barrel polishing step. Usually, cleaning of the workpieces is performed one type at a time. After the cleaning step is completed for a certain type of workpiece, the cleaning step is performed for the next type of workpiece. However, in this method, the second workpiece 20 needs to wait in the state before the cleaning step during the cleaning step of the first workpiece 10. To increase production efficiency, it is possible to go beyond conventional wisdom and mix different types of workpieces and process them simultaneously in the same cleaning device, and then sort them after the cleaning step, i.e., at the rear of the cleaning device.

[0015] In this embodiment, the plurality of workpieces 10, 20 that have been processed in such a mixed state are supplied to a part feeder 200, and a step (S20) of separating the plurality of first workpieces 10 and the plurality of second workpieces 20 from the part feeder 200 is performed.

[0016] Next, an example of a system for performing the mixing process and the separation process in this embodiment will be described with reference to Fig. 3. Fig. 3 is a top view showing a schematic configuration example of a mixed cleaning system 1000 that can be used in this embodiment. In the figure, for reference, an X-axis, a Y-axis, and a Z-axis that are perpendicular to each other are shown. In the example shown in the figure, the Z-axis is parallel to the vertical direction, and a plane (XY plane) including both the X-axis and the Y-axis is parallel to the horizontal plane.

[0017] The mixed cleaning system 1000 in this embodiment includes a cleaning device 100 that cleans a plurality of workpieces 10, 20 in a mixed state, a belt conveyor 110 that transports the plurality of workpieces 10, 20 after cleaning, and a parts feeder 200 that separates the workpieces 10, 20. The first workpiece 10 separated by the parts feeder 200 is stored in a first collection case 310, and the second workpiece is transported by the belt conveyor 120 and stored in a second collection case 320.

[0018] An example of the configuration of the part feeder 200 in this embodiment will be described below.

[0019] Fig. 4 is a top view showing a schematic diagram of part feeder 200. Fig. 5A is a schematic diagram showing a cross section of part feeder 200 taken along line AA in Fig. 4, and Fig. 5B is an enlarged schematic diagram showing a cross section of part feeder 200 taken along line BB in Fig. 4.

[0020] As shown in FIG. 5A, the part feeder 200 includes a vibration drive unit (vibrator) 22, a disk-shaped bottom 24 supported by the vibration drive unit 22, a wall 26 extending upward from the outer circumferential end of the bottom 24, and a conveying path 28 extending upward in a spiral shape from the peripheral area of ​​the bottom 24. The bottom 24 and the wall 26 form a "bowl." The outer circumferential end of the conveying path 28 is fixed and supported by the inside of the wall 26. The part feeder 200 in this embodiment is a part supplying device called a "vibration bowl hopper feeder." The main configuration of such a part feeder 200 is not limited to the example shown in the figure. The feature of the part feeder of the present disclosure is a configuration for separating the first work 10 and the second work. This configuration will be described later.

[0021] The first work 10 and the second work 20 can be supplied to the bottom 24 from above. The first work 10 and the second work 20 supplied to the bottom 24 move upward from the bottom 24 on the conveying path 28 with the vibration of the vibration drive unit 22. The conveying path 28 is inclined so that the outer periphery side of the "bowl" is lower than the inner periphery side. Therefore, the first work 10 and the second work 20 being conveyed are guided by the wall 26 while appropriately contacting the wall 26, and move side by side in the conveying direction one by one while adjusting their orientation.

[0022] 3 and 4, the spiral conveying path 28 is continuous with a conveying path 30 for separating the first work 10 and the second work. In this example, the conveying path 30 extends linearly.

[0023] Fig. 5B is a schematic cross-section of the conveying path 30 taken along line BB in Fig. 4. The part feeder 200 includes a guide member 32 disposed on one side of the plurality of workpieces 10, 20 being conveyed, and the conveying path 30 is inclined so that the side on which the guide member 32 is disposed is relatively lower. The direction and angle of this inclination may vary little by little from the connection position between the conveying path 28 and the conveying path 30.

[0024] The conveying path 30 has an opening 34 large enough to pass each of the multiple first workpieces 10 during conveying, but not each of the multiple second workpieces 20. The second workpieces 20 fall downward from this opening 34, thereby separating the first workpiece 10 from the second workpiece.

[0025] The inclination angle θ of the transport path 30 with respect to the horizontal plane has a magnitude that causes each of the multiple workpieces 10, 20 to contact the guide member 32 during transport. The inclination angle θ is, for example, in the range of 5 degrees or more and 40 degrees or less. By providing an opening 34 in the transport path 30 having an inclination angle θ (in the range of 5 degrees or more and 40 degrees or less) that is arranged so that the works 10, 20 contact the guide member 32, the transport of the works 10, 20 can be stabilized, and the works 10, 20 can be accurately selected by the opening 34.

[0026] Next, refer to FIG. 6. FIG. 6 is a top view showing an enlarged planar configuration of the conveying path 30. In a top view, the opening 34 has a shape defined by a size 34L in the length direction in the conveying direction (Y-axis direction) and a size 34W in the width direction (X-axis direction) perpendicular to the conveying direction. The size 34L is smaller than the size 10W in the width direction of the first work 10 when passing through the opening 34, and is larger than the size 20W in the width direction of the second work 20 when passing through the opening 34. In addition, the opening 34 is separated from the guide member 32 by 1 mm or more. In other words, the distance G in FIG. 6 is 1 mm or more. The distance G is sufficiently shorter than half the width 20W of the second work 20, and is in the range of, for example, 1.5 mm or more and 2.5 mm or less. In this embodiment, an area having a width equal to or greater than the value of the distance G exists on both the left and right sides of the opening 34. When the distance G is less than 1 mm, particularly 0 mm, both end portions of the first work 10 moving over the opening 34 cannot be supported by the peripheral portion of the opening 34. As a result, the first workpiece 10 falls downward through the opening 34.

[0027] Since the opening 34 has the above size and the conveyance path 30 has a region defined by the distance G on the side of the guide member 32, as shown in FIGS. 7 and 9A, when the first workpiece 10 moves over the opening 34, in order to straddle the opening 34, it does not fall downward from the opening 34. On the other hand, as shown in FIGS. 8 and 9B, the second workpiece 20 falls downward from the opening 34 while moving over the opening 34.

[0028] In order to prevent the first workpiece 10 from falling downward from the opening 34, in this embodiment, 10W > G + 34W holds. Also, in order to cause the second workpiece 20 to fall downward from the opening 34, in this embodiment, 20W < G + 34W holds. Note that the length 34L of the opening 34 does not necessarily need to be shorter than the length 10L of the first workpiece 10, nor does it necessarily need to be longer than the length 20L of the second workpiece 20. In order to cause the second workpiece 20 to fall downward from the opening 34, it is preferable that 34L > 20L × 0.7.

[0029] As shown in FIG. 3, the second workpiece 20 that has fallen from the opening 34 having the above size is conveyed to the second recovery case 320 while being placed on the belt conveyor 120 and is accommodated in the second recovery case 320. The first workpiece 10 that has passed through the opening 34 moves on the conveyance path 30 and is accommodated in the first recovery case 310.

[0030] By using the parts feeder 200 having such an opening 34 in the conveyance path 30, it becomes possible to execute the step (S10) of simultaneously processing the workpieces 10 and 20 having different varieties and improve the working efficiency of the manufacturing process.

[0031] The positions of the opening 34 and the guide member 32 in the conveyance path 30 are not limited to the above example. The inclination direction of the conveyance path 30 may be opposite to the example of FIG. 5B as shown in FIG. 10A. Even in that case, as shown in FIG. 10B, the first workpiece 10 is guided by the guide member 32 and passes over the opening 34, and as shown in FIG. 10C, the second workpiece 20 falls downward from the opening 34 guided by the guide member 32.

[0032] Although the above-mentioned conveying path 30 and guide member 32 extend linearly, the embodiment of the present disclosure is not limited to this example. The conveying path 30 and guide member 32 may extend along a curved line in top view. FIGS. 11 and 12 show the shape of the conveying path 30 in such a modified example. It is preferable that the guide member 32 is disposed on the center side of the curvature of the curve with respect to the center line of the conveying path 30. In addition, the opening 34 does not need to be a simple rectangle, and may extend along the curve as a whole by combining multiple rectangles or sector shapes, as shown in FIG. 12, for example. In the example shown in FIG. 12, the opening 34 has a shape in which two rectangles are overlapped with their orientation and position changed. By appropriately designing the opening 34 based on the shape and size of the work to be separated, it becomes possible to separate various workpieces. In a form in which the workpiece has a rectangular shape in top view and the conveying path extends along a curved line, it is preferable to give the opening 34 a shape that combines several simple figures such as rectangles, as shown in FIG. 12, for example.

[0033] The present disclosure includes the inventions described in the following items. [Item 1] A step of simultaneously processing a plurality of workpieces including a plurality of first workpieces and a plurality of second workpieces each having a size smaller than that of each of the plurality of first workpieces; supplying the plurality of workpieces that have been subjected to the processing to a part feeder, and separating the plurality of first workpieces and the plurality of second workpieces from the part feeder; Including, The part feeder includes a conveying path for conveying the plurality of workpieces, and a guide member disposed on one side of the conveying path; The transport path is The side on which the guide member is disposed is inclined relatively lower, the opening is large enough to allow each of the plurality of first workpieces to pass through while being transported, but not large enough to allow each of the plurality of second workpieces to pass through. [Item 2] 2. The method for producing a rare earth sintered magnet according to item 1, wherein an inclination angle of the transport path with respect to a horizontal plane is such that each of the plurality of workpieces contacts the guide member during transport. [Item 3] 3. The method for producing a rare earth sintered magnet according to item 1 or 2, wherein the inclination angle is within a range of 5 degrees or more and 40 degrees or less. [Item 4] the conveying path and the guide member extend along a curved line in a top view, 4. The method for producing a rare earth sintered magnet according to any one of items 1 to 3, wherein the guide member is disposed on the center side of the curvature of the curve with respect to a center line of the transport path. [Item 5] 5. The method for producing a rare earth sintered magnet according to item 4, wherein the opening extends along the curved line in the top view. [Item 6] 6. The method for producing a rare earth sintered magnet according to any one of items 1 to 5, wherein the opening is spaced from the guide member by 1 mm or more. [Item 7] 7. The method for producing a rare earth sintered magnet according to any one of items 1 to 6, wherein the size of the opening in the width direction perpendicular to the conveying direction is smaller than the size of each of the plurality of first workpieces in the width direction when they pass through the opening, and is larger than the size of each of the plurality of second workpieces in the width direction when they pass through the opening. [Item 8] 8. The method for producing a rare earth sintered magnet according to any one of items 1 to 7, wherein, in the top view, each of the plurality of first workpieces has a first rectangular shape, and each of the plurality of second workpieces has a second rectangular shape. [Item 9] 10. The method for producing a rare earth sintered magnet according to any one of claims 1 to 9, wherein each of the plurality of workpieces is a sintered body of rare earth alloy powder in the middle of production. [Item 10] 11. The method for producing a rare earth sintered magnet according to any one of items 1 to 10, wherein the treatment is washing or barrel polishing of the plurality of workpieces. [Industrial Applicability]

[0034] The embodiment of the present invention is characterized in that the H of the RTB-based sintered magnet is reduced by using less heavy rare earth element RH. cJ Therefore, the present invention can be used to manufacture rare earth sintered magnets that require high coercivity. The present invention can also be widely applied to techniques that require diffusing metal elements other than the heavy rare earth element RH into a rare earth sintered magnet from the surface. [Explanation of symbols]

[0035] 10. First work 20. Second Work 30...Transport path 32 Guide member 34 Opening 100 Cleaning equipment 110...Conveyor belt 120···Conveyor belt 200···Parts feeder 310... First collection case 320...Second collection case 1000···Mixed cleaning system

Claims

1. A step of simultaneously processing a plurality of workpieces including a plurality of first workpieces and a plurality of second workpieces each having a size smaller than that of each of the plurality of first workpieces; supplying the plurality of workpieces that have been subjected to the processing to a part feeder, and separating the plurality of first workpieces and the plurality of second workpieces from the part feeder; Including, The part feeder includes a conveying path for conveying the plurality of workpieces, and a guide member disposed on one side of the conveying path; The transport path is The side on which the guide member is disposed is inclined relatively lower, the opening is sized to allow each of the plurality of first workpieces to pass through while being transported, but not each of the plurality of second workpieces to pass through.

2. 2. The method for producing a rare earth sintered magnet according to claim 1, wherein an inclination angle of said transport path with respect to a horizontal plane is large enough to bring each of said plurality of workpieces into contact with said guide member during transport.

3. The method for producing a rare earth sintered magnet according to claim 2 , wherein the inclination angle is in the range of 5 degrees to 40 degrees.

4. the conveying path and the guide member extend along a curved line in a top view, The method for producing a rare earth sintered magnet according to claim 3 , wherein the guide member is disposed on a center side of the curvature of the curve with respect to a center line of the transport path.

5. The method for producing a rare earth sintered magnet according to claim 4 , wherein the opening extends along the curve when viewed from above.

6. The method for producing a rare earth sintered magnet according to claim 5 , wherein the opening is spaced from the guide member by 1 mm or more.

7. 7. A method for producing a rare earth sintered magnet according to claim 1, wherein the size of the opening in the width direction perpendicular to the conveying direction is smaller than the size of each of the plurality of first workpieces in the width direction when they pass through the opening, and is larger than the size of each of the plurality of second workpieces in the width direction when they pass through the opening.

8. 5. The method for producing a rare earth sintered magnet according to claim 4, wherein, when viewed from the top, each of the plurality of first workpieces has a first rectangular shape, and each of the plurality of second workpieces has a second rectangular shape.

9. 2. The method for producing a rare earth sintered magnet according to claim 1, wherein each of the plurality of workpieces is a sintered body of rare earth alloy powder in the process of being produced.

10. The method for producing a rare earth sintered magnet according to claim 1 , wherein the treatment is cleaning or barrel polishing of the plurality of workpieces.

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