Neodymium-iron-boron magnet preparation control method, system, equipment and medium

Abstract

The invention discloses a neodymium-iron-boron magnet preparation control method, system and equipment and a medium, and the method comprises the following steps: completing the pre-compaction operation of neodymium-iron-boron magnetic powder based on the control of a special mold, so as to form a first blank body; obtaining a blind hole depth image after the core rod is extracted based on the side view angle of the barrel mold; identifying whether the blind hole has a first defect feature; if yes, supplementary compaction operation on the blind hole is controlled to be completed; if not, hole forming operation on the first blank body is controlled to be completed, so that a second blank body is formed; the second blank body is provided with an inverted conical hole and a spherical bulge; acquiring a laser scanning three-dimensional image of the inverted conical hole and the spherical bulge based on the overlook angle of the barrel mold; identifying whether the spherical bulge has a second defect feature or not; if yes, the supplementary compaction operation on the spherical protrusions is controlled to be completed; if not, thermal deformation treatment on the second blank is controlled to be completed, and the neodymium-iron-boron magnet is manufactured, and the neodymium-iron-boron magnet manufacturing method has the advantage that the defect detection accuracy in the magnet manufacturing process is improved.

Description

Technical Field

[0001] The present application relates to the field of industrial production control technology, and in particular to a method, system, equipment and medium for controlling the preparation of NdFeB magnets. Background Art

[0002] At present, the preparation process of NdFeB magnets includes preparing magnetic powder, cold pressing and hot pressing the prepared magnetic powder, and finally performing thermal deformation treatment. At the same time, the corresponding mold can be used to produce NdFeB magnets with corresponding shapes and structures. However, the shape and structure of NdFeB magnets vary according to their application fields and performance requirements. Now, a NdFeB magnet with a special structure is prepared. The NdFeB magnet is cylindrical in shape, with multiple blind holes on its side walls, an inverted conical hole on its top, and a spherical protrusion on the bottom of the inverted conical hole. During the preparation process, due to its special structure, defect detection is required at each key molding node, such as the blind hole depth and the compaction degree of the spherical protrusion, in order to control the molding quality requirements. At present, the process progress is mainly controlled by manual inspection, and the detection accuracy and efficiency are relatively low, which affects the process preparation process. Summary of the Invention

[0003] The main purpose of this application is to provide a method, system, equipment and medium for controlling the preparation of NdFeB magnets, aiming to solve the technical problem of low defect detection accuracy in existing NdFeB magnet preparation control methods.

[0004] To achieve the above objectives, the present application provides a method for controlling the preparation of NdFeB magnets, comprising the following steps: A pre-compacting operation of the NdFeB magnetic powder is completed based on control of a custom mold to form a first embryonic body. The custom mold includes a cylindrical mold having a cavity. A plurality of core rods are movably provided through the side wall of the cylindrical mold. The core rods extend into the cavity and are used to form blind holes in the side wall of the first embryonic body. Obtain the blind hole depth image after the core rod is extracted based on the side view of the barrel mold; Identify whether the blind hole has a first defect feature based on the blind hole depth image; wherein the first defect feature is a concave feature formed by the uncompacted hole end surface of the blind hole; If so, the control is to complete the additional compaction operation of the blind hole after the mandrel is installed, and return to the perspective facing the side wall of the barrel mold to obtain the blind hole depth image after the mandrel is removed; if not, the control is to complete the hole-making operation of the first embryonic body to form a second embryonic body; wherein the second embryonic body has an inverted tapered hole on the top and a spherical protrusion on the bottom of the inverted tapered hole; The laser scanning 3D images of the inverted tapered hole and spherical protrusion are obtained based on the top view of the cylinder mold; Identify whether the spherical protrusion has a second defect feature based on the laser scanning three-dimensional image; wherein the second defect feature is a concave feature formed by the uncompacted surface of the spherical protrusion; If so, the control is to complete the supplementary compaction operation on the spherical protrusion, and return to the top view based on the cylindrical mold to obtain the laser scanning three-dimensional image of the inverted conical hole and the spherical protrusion; if not, the control is to complete the thermal deformation treatment of the second embryo to obtain the neodymium iron boron magnet.

[0005] Optionally, identifying whether the blind hole has a first defect feature according to the blind hole depth image includes: Obtaining depth values of a plurality of pixel points corresponding to the end surface of the blind hole according to the blind hole depth image; Get the maximum value of the depth values of multiple pixels; Determine whether the maximum value is greater than a preset first depth threshold; if so, identify the presence of a first defect feature in the blind hole; if not, select target pixels having a depth value greater than a preset second depth threshold; wherein the second depth threshold is less than the first depth threshold; Obtain an average value h of the depth values corresponding to the multiple target pixels and the number n of the multiple target pixels; Get the first defect value Q; where Q=n h; It is determined whether the first defect value Q is greater than a preset defect threshold value. If so, it is determined that the blind hole has the first defect feature. If not, it is determined that the blind hole does not have the first defect feature.

[0006] Optionally, identifying whether the spherical protrusion has a second defect feature based on the laser scanning three-dimensional image includes: Constructing a three-dimensional coordinate system based on the laser scanning three-dimensional image; wherein the coordinate origin of the three-dimensional coordinate system is located on the axis line of the spherical convexity; Based on the three-dimensional coordinate system, obtain the vertex coordinates of the spherical protrusion; Compare the vertex coordinates with the theoretical coordinates to obtain the z-axis coordinate difference; wherein the theoretical coordinates are the coordinate positions of the vertex of the spherical protrusion when there is no depression; Determine whether the z-axis coordinate difference is greater than a preset first threshold value. If so, identify the presence of a second defect feature in the spherical protrusion. If not, obtain reference coordinates of the inner wall of the inverted tapered hole at different positions; wherein the reference coordinates are lower than the vertex coordinates. Obtaining associated coordinates corresponding to the surface of the spherical convex surface and the reference coordinates; wherein the z-coordinate values of the associated coordinates and the reference coordinates are equal, and a line connecting the associated coordinates and the reference coordinates passes through the axis of the spherical convex surface; Get the coordinate distance value between the associated coordinate and the reference coordinate; It is determined whether the coordinate distance value is greater than a preset second threshold value. If so, it is identified that the spherical protrusion has the second defect feature. If not, it is identified that the spherical protrusion does not have the second defect feature.

[0007] Optionally, obtaining reference coordinates of the inner wall of the inverted tapered hole at different positions includes: A plurality of discrete first reference coordinates are selected around a first height position of the inner wall of the inverted tapered hole; wherein the first height position is lower than the vertex coordinate of the spherical protrusion; If the coordinate distance between the first reference coordinate and the corresponding associated coordinate is less than or equal to the corresponding second threshold, a plurality of discrete second reference coordinates are selected around a second height position of the inner wall of the inverted tapered hole; wherein the second height position is lower than the first height position; If the coordinate distance between the second reference coordinate and the corresponding associated coordinate is less than or equal to the corresponding second threshold, a plurality of discrete third reference coordinates are selected around a third height position of the inner wall of the inverted tapered hole; wherein the third height position is lower than the second height position; Until the end condition is reached; wherein, the end condition is that the current reference coordinate reaches a preset minimum height position or the coordinate distance value between the current reference coordinate and the corresponding associated coordinate is greater than the corresponding second threshold.

[0008] Optionally, controlling the additional compaction of the blind hole after the mandrel is installed includes: Controlling the first hydraulic component to press into the first embryonic body to form a filling hole in the middle of the first embryonic body; wherein the first hydraulic component includes a first hydraulic plate, a core column for forming the filling hole is connected to the bottom of the first hydraulic plate, and the bottom of the filling hole is lower than the position of the blind hole; The filling hole is controlled to be filled with NdFeB magnetic powder, and the second hydraulic plate is controlled to compact the filled first embryonic body to complete the supplementary compaction operation of the blind hole.

[0009] Optionally, controlling and completing the hole-making operation on the first embryonic body to form a second embryonic body includes: The second hydraulic component is controlled to be pressed into the first embryo to form a second embryo; wherein the second hydraulic component includes a third hydraulic plate, the bottom of the third hydraulic plate is connected to an inverted conical column, and the bottom of the inverted conical column is provided with an inner groove for forming a spherical protrusion.

[0010] Optionally, controlling and completing a supplementary compaction operation on the spherical protrusion includes: Controlling the addition of a corresponding amount of NdFeB magnetic powder to the raised area of the spherical surface; The second hydraulic component is controlled to press the second embryonic body into the spherical protrusion to complete the supplementary compaction operation on the spherical protrusion.

[0011] To achieve the above objectives, the present application also provides a neodymium iron boron magnet preparation control system, comprising: a first control module for controlling, based on a custom mold, pre-compacting the NdFeB magnetic powder to form a first embryonic body; wherein the custom mold comprises a cylindrical mold having a cavity, wherein a plurality of core rods are movably disposed through a side wall of the cylindrical mold, the core rods extending into the cavity and used to form blind holes in the side wall of the first embryonic body; The first image acquisition module is used to acquire a blind hole depth image after the core rod is extracted based on a side view of the barrel mold; A first defect recognition module is configured to identify whether the blind hole has a first defect feature based on the blind hole depth image; wherein the first defect feature is a concave feature formed by an uncompacted hole end surface of the blind hole; A second control module is configured to, if yes, control the completion of the additional compaction operation on the blind hole after the mandrel is installed, and return to the state of obtaining a blind hole depth image after the mandrel is removed based on a perspective facing the side wall of the barrel mold; if no, control the completion of the hole forming operation on the first embryonic body to form a second embryonic body; wherein the second embryonic body has an inverted tapered hole on the top and a spherical protrusion on the bottom of the inverted tapered hole; The second image acquisition module is used to acquire a laser scanning three-dimensional image of the inverted tapered hole and the spherical protrusion based on a top-down perspective of the cylindrical mold; A second defect recognition module is used to identify whether the spherical protrusion has a second defect feature based on the laser scanning three-dimensional image; wherein the second defect feature is a concave feature formed by the uncompacted surface of the spherical protrusion; The third control module is used to control the completion of the supplementary compaction operation on the spherical protrusion and return to the top view of the cylinder mold to obtain the laser scanning three-dimensional image of the inverted conical hole and the spherical protrusion; if not, control the completion of the thermal deformation treatment of the second embryo to obtain the neodymium iron boron magnet.

[0012] To achieve the above objectives, the present application also provides a computer device, which includes a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the above method.

[0013] To achieve the above objectives, the present application also provides a computer-readable storage medium, on which a computer program is stored. A processor executes the computer program to implement the above method.

[0014] The beneficial effects that can be achieved by this application are as follows: The present application first completes the pre-compaction operation of NdFeB magnetic powder based on a special mold control to form a first embryonic body, and the core rod in the special mold is detachable and withdrawn, so that the blind hole depth image after the core rod is extracted can be directly obtained based on the side view of the cylindrical mold in the future, without taking out the first embryonic body, reducing the risk of secondary damage to the first embryonic body during the removal process, and the blind hole depth image can include the hole end face depth value of the blind hole. If there is a concave feature formed by the hole end face of the blind hole that is not compacted, the corresponding depth value has a significant gap with the theoretical value, so that the first defect feature can be identified based on this. If the first defect feature is identified, the control completes the supplementary compaction operation of the blind hole after the core rod is installed, and then continues to detect whether the first defect feature exists until the first defect feature disappears, and then controls the completion of the hole making operation of the first embryonic body to form a second embryonic body. Due to this The second embryonic body has an inverted conical hole at the top and a spherical protrusion at the bottom of the inverted conical hole, and its internal structure is relatively complex. Therefore, a laser scanning three-dimensional image of the inverted conical hole and the spherical protrusion is obtained based on the top-down perspective of the cylindrical mold, so that the three-dimensional appearance of the inverted conical hole and the spherical protrusion can be reconstructed. Based on the laser scanning three-dimensional image, it can be identified whether the spherical protrusion has a concave feature formed by uncompacted surface, that is, the second defect feature. If so, the spherical protrusion is controlled to complete the supplementary compaction operation and is tested again until the second defect feature disappears. Finally, the thermal deformation treatment of the second embryonic body can be controlled to produce NdFeB magnets. In this process, machine vision recognition and laser scanning technology are used to detect the corresponding defects at the two key nodes of blind hole and inverted conical hole, respectively, which improves the accuracy of defect detection, thereby facilitating higher quality NdFeB magnets. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] To more clearly illustrate the specific embodiments of this application or the technical solutions in the prior art, the following briefly describes the drawings required for the specific embodiments or the description of the prior art. Similar elements or parts are generally identified by similar reference numerals throughout the drawings. Elements or parts in the drawings are not necessarily drawn to scale.

[0016] Figure 1 Schematic diagram of a process for controlling the preparation of NdFeB magnets in an embodiment of the present application; Figure 2 Schematic diagram of the structure of the NdFeB magnet in the embodiment of the present application; Figure 3 Schematic diagram of the structure of pre-compacting NdFeB magnetic powder to form a first embryonic body in an embodiment of the present application; Figure 4 This is a schematic structural diagram of the embodiment of the present application when the core rod and the second hydraulic plate are removed; Figure 5Schematic diagram of the structure when the first hydraulic component is pressed into the first embryonic body to form a filling hole in an embodiment of the present application; Figure 6 This is a structural diagram of the embodiment of the present application in which NdFeB magnetic powder is filled into the filling hole and the filled first embryo body is compacted by the second hydraulic plate; Figure 7 Schematic diagram of the structure when the second hydraulic component is pressed into the first embryonic body to form the second embryonic body in an embodiment of the present application; Figure 8 This is a schematic structural diagram of the embodiment of the present application when the second hydraulic component is removed; Figure 9 This is a schematic diagram of obtaining vertex coordinates, reference coordinates, and associated coordinates based on laser scanning of a three-dimensional image in an embodiment of the present application; Figure 10 for Figure 9 Schematic diagram of the top view.

[0017] Reference numerals: 110-NdFeB magnet, 111-blind hole, 112-inverted tapered hole, 113-spherical protrusion, 120-special mold, 121-cylinder mold, 122-core rod, 130-first embryo, 131-filling hole, 140-first hydraulic part, 141-first hydraulic plate, 142-core column, 150-second hydraulic plate, 160-second hydraulic part, 161-third hydraulic plate, 162-inverted tapered column, 163-inner groove, 170-second embryo.

[0018] The realization of the objectives, functional features and advantages of this application will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0019] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0020] It should be noted that if there are descriptions involving "first", "second", etc. in the embodiments of the present application, the descriptions of "first", "second", etc. are only for descriptive purposes and cannot be understood as indicating or suggesting their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of such features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the fact that they can be implemented by ordinary technicians in this field. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by this application.

[0021] Example 1: Reference Figures 1-10 This embodiment provides a method for controlling the preparation of NdFeB magnets, comprising the following steps: The NdFeB magnetic powder is pre-compacted based on a custom mold 120 to form a first embryonic body 130. The custom mold 120 includes a cylindrical mold 121 having a cavity. A plurality of core rods 122 are movably disposed through the sidewall of the cylindrical mold 121. The core rods 122 extend into the cavity and are used to form blind holes 111 in the sidewall of the first embryonic body 130. Obtaining a blind hole depth image after the core rod 122 is extracted based on a side view of the cylindrical mold 121; Identify whether the blind hole 111 has a first defect feature based on the blind hole depth image; wherein the first defect feature is a concave feature formed by the uncompacted hole end surface of the blind hole 111; If so, the control is to complete the additional compaction operation on the blind hole 111 after installing the core rod 122, and return to the viewpoint facing the side wall of the cylindrical mold 121 to obtain the blind hole depth image after the core rod 122 is removed. If not, the control is to complete the hole forming operation on the first embryonic body 130 to form the second embryonic body 170. The second embryonic body 170 has an inverted tapered hole 112 on the top, and a spherical protrusion 113 on the bottom of the inverted tapered hole 112. Acquire a laser scanning three-dimensional image of the inverted tapered hole 112 and the spherical protrusion 113 based on a top view of the cylinder mold 121; Identify whether the spherical protrusion 113 has a second defect feature based on the laser scanning three-dimensional image; wherein the second defect feature is a concave feature formed by the surface of the spherical protrusion 113 not being compacted; If so, the control is to complete the supplementary compaction operation on the spherical protrusion 113, and return to the laser scanning three-dimensional image based on the top view of the cylindrical mold 121 to obtain the inverted conical hole 112 and the spherical protrusion 113; if not, the control is to complete the thermal deformation treatment of the second embryo 170 to obtain the neodymium iron boron magnet 110.

[0022] In this embodiment, the pre-compacting operation of the NdFeB magnetic powder is first completed based on the control of the special mold 120 to form the first embryo 130. Since the first embryo 130 is subjected to axial pressure and its radial pressure is small when the NdFeB magnetic powder is pressed and formed, the pressure on the end of the core rod 122 is relatively low, resulting in the NdFeB magnetic powder at the end of the core rod 122 being difficult to compact tightly. The end surface of the blind hole 111 formed in the end is prone to depression. Therefore, the core rod 122 in the special mold 120 is disassembled and pulled out, so that it can be directly based on the side view of the cylindrical mold 121 in the future. The blind hole depth image after the core rod 122 is extracted is obtained, and the first embryonic body 130 does not need to be removed, thereby reducing the risk of secondary damage to the first embryonic body 130 during the removal process. The blind hole depth image may include the hole end face depth value of the blind hole 111. If there is a concave feature formed by the hole end face of the blind hole 111 that is not compacted, the corresponding depth value has a significant difference from the theoretical value, so that the first defect feature can be identified based on this. If the first defect feature is identified, the control is completed to complete the supplementary compaction operation of the blind hole 111 after the installation of the core rod 122, and then continue to detect whether the first defect feature exists until the first defect feature disappears. , and then the hole making operation of the first embryo 130 is controlled to be completed to form the second embryo 170. Since the second embryo 170 has an inverted conical hole 112 on the top and a spherical protrusion 113 on the bottom of the inverted conical hole 112, the spherical protrusion 113 is easily not compacted and appears concave due to the uneven pressure, and the internal structure is relatively complex. Therefore, the laser scanning three-dimensional image of the inverted conical hole 112 and the spherical protrusion 113 is obtained based on the top view of the cylindrical mold 121, so that the three-dimensional appearance of the inverted conical hole 112 and the spherical protrusion 113 can be reconstructed. The three-dimensional image is used to identify whether the spherical protrusion 113 has a concave feature formed by uncompacted surface, i.e., the second defect feature. If so, the spherical protrusion 113 is controlled to be supplemented with compaction, and the test is performed again until the second defect feature disappears. Finally, the second embryonic body 170 is controlled to be thermally deformed to produce the NdFeB magnet 110. In this process, machine vision recognition and laser scanning technology are used to detect the corresponding defects at the two key nodes of the blind hole 111 and the inverted tapered hole 112, respectively, to improve the accuracy of defect detection, thereby facilitating the production of higher-quality NdFeB magnets 110.

[0023] It should be noted that during the pre-compaction operation, the NdFeB magnetic powder in the cylindrical mold 121 is pressed to a certain thickness by the second hydraulic plate 150, and then the second hydraulic plate 150 and the core rod 122 are taken out at the same time for subsequent depth image detection. Here, the core rod 122 can be connected to the cylindrical mold 121 by a thread, which is convenient for disassembly and installation, and the installation depth can be adjusted to form blind holes 111 with different depth requirements.

[0024] As an optional implementation, identifying whether the blind hole 111 has the first defect feature according to the blind hole depth image includes: According to the blind hole depth image, depth values of a plurality of pixel points corresponding to the hole end surface of the blind hole 111 are obtained; Get the maximum value of the depth values of multiple pixels; Determine whether the maximum value is greater than a preset first depth threshold. If so, identify the presence of a first defect feature in the blind hole 111. If not, select target pixels having a depth value greater than a preset second depth threshold; wherein the second depth threshold is less than the first depth threshold. Obtain an average value h of the depth values corresponding to the multiple target pixels and the number n of the multiple target pixels; Get the first defect value Q; where Q=n h; It is determined whether the first defect value Q is greater than a preset defect threshold value. If so, it is determined that the blind hole 111 has the first defect feature. If not, it is determined that the blind hole 111 does not have the first defect feature.

[0025] In this embodiment, the depth values of multiple pixel points corresponding to the hole end surface of the blind hole 111 can be obtained based on the blind hole depth image. The maximum value of the depth values of the multiple pixel points is first identified, and it is determined whether the maximum value is greater than a preset first depth threshold. If so, it means that the pixel point corresponding to the maximum depth value and its surrounding area have obvious depressions. At this time, the blind hole 111 can be identified as having a first defect feature. If not, in order to improve the detection accuracy, the target pixel points with depth values greater than the preset second depth threshold are further screened out, that is, the depth values of the target pixel points are between the second depth threshold and the first depth threshold. Then, the multiple target pixels are selected. The product of the average value h of the depth value corresponding to the point and the number n of multiple target pixel points is output as the first defect value Q, which can quantitatively represent the size of the defect area of the hole end face of the blind hole 111. If it is greater than the preset defect threshold, the blind hole 111 is still identified as having the first defect feature. Through double detection, the detection accuracy of the blind hole 111 defect can be effectively improved. Here, the detection order is based on first detecting the maximum value in the depth value and the first defect value Q. This is because it can be quickly identified when the maximum value is detected. When the blind hole 111 is identified as having the first defect feature based on the maximum value, there is no need to proceed to the next step of detection, which reduces data processing pressure and improves detection efficiency.

[0026] As an optional embodiment, identifying whether the spherical protrusion 113 has a second defect feature based on the laser scanning three-dimensional image includes: Constructing a three-dimensional coordinate system based on the laser scanning three-dimensional image; wherein the coordinate origin of the three-dimensional coordinate system is located on the axis line of the spherical protrusion 113; Based on the three-dimensional coordinate system, the vertex coordinates of the spherical protrusion 113 are obtained; Compare the vertex coordinates with the theoretical coordinates to obtain the z-axis coordinate difference; wherein the theoretical coordinates are the coordinate positions of the vertex of the spherical protrusion 113 when there is no depression; Determine whether the z-axis coordinate difference is greater than a preset first threshold value. If so, identify the presence of a second defect feature in the spherical protrusion 113. If not, obtain reference coordinates of the inner wall of the inverted tapered hole 112 at different positions; wherein the reference coordinates are lower than the vertex coordinates. Obtaining associated coordinates of the surface of the spherical protrusion 113 corresponding to the reference coordinates; wherein the z-coordinate values of the associated coordinates and the reference coordinates are equal, and a line connecting the associated coordinates and the reference coordinates passes through the axis of the spherical protrusion 113; Get the coordinate distance value between the associated coordinate and the reference coordinate; It is determined whether the coordinate distance value is greater than a preset second threshold value. If so, it is determined that the spherical protrusion 113 has the second defect feature. If not, it is determined that the spherical protrusion 113 does not have the second defect feature.

[0027] In this embodiment, a three-dimensional coordinate system can be constructed based on the laser scanning three-dimensional image. Here, the coordinate origin O of the three-dimensional coordinate system can be set at the theoretical coordinate position. Since the top of the spherical protrusion 113 is likely to be concave, the vertex coordinates of the spherical protrusion 113 are first obtained here, marked as H (0, 0, z0), and the z-axis coordinate difference between the vertex coordinates and the theoretical coordinates can be calculated. The z-axis coordinate difference is z0. Taking into account the allowable error, a first threshold is set here. When the z-axis coordinate difference is greater than the first threshold, the spherical protrusion 113 can be identified as having a second defect feature. On the contrary, considering that other surface areas of the spherical protrusion 113 may also have concave surfaces, and since the inner wall of the inverted tapered hole 112 is an inclined surface, it is easier to withstand axial pressure, so there is basically no concave situation. Therefore, the reference coordinates of the inner wall of the inverted tapered hole 112 at different positions can be selected as reference points. The reference coordinates are marked as (x n ,y n , z n ), and each reference coordinate has a corresponding associated coordinate on the surface of the spherical protrusion 113, and the associated coordinate is marked as (x n ',y n ', z n '), since the z-coordinate values of the reference coordinate and its corresponding associated coordinate are equal, that is, z n =z n', therefore, only the coordinate distance value of the two coordinates in the horizontal direction needs to be calculated. Also, considering the allowable error, a second threshold value is set here. When the coordinate distance value is greater than the second threshold value, the second defect feature of the spherical protrusion 113 can be identified. Therefore, this embodiment is based on the probability of the spherical protrusion 113 being concave. By first identifying the vertex coordinates with a higher probability of concave occurrence and then identifying the associated coordinates with a lower probability of concave occurrence, if the vertex coordinate is identified as having a concave feature, there is no need to perform the next step of associated coordinate detection. By rationally planning the detection sequence, both detection accuracy and detection efficiency are guaranteed.

[0028] As an optional embodiment, obtaining the reference coordinates of the inner wall of the inverted tapered hole 112 at different positions includes: A plurality of discrete first reference coordinates are selected around a first height position of the inner wall of the inverted tapered hole 112; wherein the first height position is lower than the vertex coordinate of the spherical protrusion 113; If the coordinate distance between the first reference coordinate and the corresponding associated coordinate is less than or equal to the corresponding second threshold, a plurality of discrete second reference coordinates are selected around a second height position of the inner wall of the inverted tapered hole 112; wherein the second height position is lower than the first height position; If the coordinate distance between the second reference coordinate and the corresponding associated coordinate is less than or equal to the corresponding second threshold, a plurality of discrete third reference coordinates are selected around a third height position of the inner wall of the inverted tapered hole 112; wherein the third height position is lower than the second height position; Until the end condition is reached; wherein, the end condition is that the current reference coordinate reaches a preset minimum height position or the coordinate distance value between the current reference coordinate and the corresponding associated coordinate is greater than the corresponding second threshold.

[0029] In this embodiment, due to the different directions of pressure, the probability of the surface of the spherical protrusion 113 not being compacted and being concave at different height positions is different. Generally, the closer to the top position, the greater the probability of concave. Therefore, when selecting the reference coordinates here, they are selected from top to bottom along the different height positions of the inner wall of the inverted conical hole 112. At the same time, a different number of reference coordinates are selected at each height position. Since the inner diameter of the inverted conical hole 112 decreases from top to bottom, the number of reference coordinates selected can be less as it goes down. For example, when multiple discrete first reference coordinates are selected at the first height position of the inner wall of the inverted conical hole 112, they are respectively recorded as a(x1, y1, z1), a(x2, y2, z2), a(x3, y3, z3)...a(x n ,y n , z n), the corresponding associated coordinates are a'(x1', y1', z1'), a'(x2', y2', z2'), a'(x3', y3', z3')...a'(x n ',y n ', z n '), respectively calculate the coordinate distance value of each first reference coordinate and the corresponding associated coordinate. If the coordinate distance value is greater than the corresponding second threshold value (the distance height position is different, and the second threshold value corresponds to different values here), there is no need to calculate the coordinate distance value of the next layer of height, and the second defect feature of the spherical protrusion 113 can be directly identified to save detection time and improve detection efficiency. If all the coordinate distance values calculated at the first height position are less than the corresponding second threshold value, then a plurality of second reference coordinates are selected along the inner wall of the inverted tapered hole 112 at a second height position lower than the first height position, and are recorded as b(x1, y1, z1), b(x2, y2, z2), b(x3, y3, z3)...b(x n ,y n , z n ), the corresponding associated coordinates are b'(x1', y1', z1'), b'(x2', y2', z2'), b'(x3', y3', z3')...b'(x n ',y n ', z n '), similarly, if all coordinate distance values calculated based on the second height position are less than the corresponding second threshold value, then continue to select multiple third reference coordinates along the inner wall of the inverted tapered hole 112 based on a third height position lower than the second height position, and calculate the coordinate distance value again until the current reference coordinate reaches the preset lowest height position or the coordinate distance value between the current reference coordinate and the corresponding associated coordinate is greater than the corresponding second threshold value, thereby realizing defect detection at different heights according to the probability of occurrence of depressions, improving detection efficiency, and ensuring detection accuracy.

[0030] It should be noted that when it is necessary to select reference coordinates at the lower height, the reference coordinates at the lower height are staggered relative to the reference coordinates at the upper height in the radial direction of the spherical protrusion 113, thereby increasing the discreteness of the coordinate selection point and improving the detection accuracy.

[0031] As an optional embodiment, controlling the additional compaction operation of the blind hole 111 after the installation of the core rod 122 is completed includes: The first hydraulic component 140 is controlled to be pressed into the first embryonic body 130 to form a filling hole 131 in the middle of the first embryonic body 130. The first hydraulic component 140 includes a first hydraulic plate 141. A core column 142 for forming the filling hole 131 is connected to the bottom of the first hydraulic plate 141. The bottom of the filling hole 131 is lower than the position of the blind hole 111. The filling hole 131 is controlled to be filled with NdFeB magnetic powder, and the second hydraulic plate 150 is controlled to compact the filled first embryonic body 130 to complete the supplementary compaction operation on the blind hole 111 .

[0032] In this embodiment, when the blind hole 111 is supplementarily compacted, the first hydraulic component 140 having the core column 142 is first controlled to be pressed into the first embryonic body 130. Since the core column 142 can extend below the height of the core rod 122, a radial extrusion force is generated on the NdFeB magnetic powder in the end area of the core rod 122 through the core column 142, so as to promote the NdFeB magnetic powder to be tightly compacted at the end of the core rod 122, thereby achieving the compaction treatment of the hole end surface of the blind hole 111. At this time, after the first hydraulic component 140 is pulled out, a filling hole 131 will be formed, and then the filling hole 131 is controlled to be filled with NdFeB magnetic powder, and then the second hydraulic plate 150 is controlled to compact the filled first embryonic body 130, thereby effectively achieving the compaction treatment operation of the lateral blind hole 111.

[0033] As an optional embodiment, controlling and completing the hole-making operation on the first embryonic body 130 to form the second embryonic body 170 includes: The second hydraulic component 160 is controlled to be pressed into the first embryo 130 to form the second embryo 170; wherein, the second hydraulic component 160 includes a third hydraulic plate 161, and the bottom of the third hydraulic plate 161 is connected to an inverted conical column 162, and the bottom of the inverted conical column 162 is provided with an inner groove 163 for forming the spherical protrusion 113.

[0034] In this embodiment, when the second embryonic body 170 is press-formed, the second hydraulic component 160 having the corresponding core mold can be controlled to press into the first embryonic body 130 , thereby forming the corresponding inverted conical hole 112 and spherical protrusion 113 through the inverted conical column 162 and the inner groove 163 .

[0035] As an optional embodiment, controlling and completing the supplementary compaction operation on the spherical protrusion 113 includes: Controlling the addition of a corresponding amount of NdFeB magnetic powder to the spherical protrusion 113 area; The second hydraulic component 160 is controlled to press the second embryonic body 170 toward the spherical protrusion 113 , so as to complete the supplementary compaction operation on the spherical protrusion 113 .

[0036] In this embodiment, when the spherical protrusion 113 is supplementarily compacted, after taking out the second hydraulic component 160, a corresponding amount of NdFeB magnetic powder is controlled to be added to the area of the spherical protrusion 113, and then the second hydraulic component 160 is controlled to align with the spherical protrusion 113 and pressed into the second embryo 170. Finally, when performing the thermal deformation treatment, the second hydraulic component 160 is kept in the cylindrical mold 121, and pressure is gradually applied to finally form a NdFeB magnet 110 of corresponding size.

[0037] Example 2: Based on the same inventive concept as the above embodiment, this embodiment further provides a neodymium iron boron magnet preparation control system, comprising: A first control module is configured to control the pre-compaction of the NdFeB magnetic powder based on a custom mold 120 to form a first embryonic body 130. The custom mold 120 includes a cylindrical mold 121 having a cavity. A plurality of core rods 122 are movably disposed through the sidewall of the cylindrical mold 121. The core rods 122 extend into the cavity and are configured to form blind holes 111 in the sidewall of the first embryonic body 130. A first image acquisition module is used to acquire a blind hole depth image after the core rod 122 is extracted based on a side view of the cylindrical mold 121; A first defect recognition module is configured to identify whether the blind hole 111 has a first defect feature based on the blind hole depth image; wherein the first defect feature is a concave feature formed by an uncompacted hole end surface of the blind hole 111; The second control module is configured to, if yes, control the completion of the additional compaction operation on the blind hole 111 after the mandrel 122 is installed, and return to the state of obtaining a blind hole depth image after the mandrel 122 is removed based on the perspective facing the side wall of the cylindrical mold 121; if no, control the completion of the hole forming operation on the first embryonic body 130 to form a second embryonic body 170; wherein the second embryonic body 170 has an inverted tapered hole 112 on the top, and a spherical protrusion 113 on the bottom of the inverted tapered hole 112; The second image acquisition module is used to acquire a laser scanning three-dimensional image of the inverted tapered hole 112 and the spherical protrusion 113 based on a top view of the cylindrical mold 121; The second defect recognition module is used to identify whether the spherical protrusion 113 has a second defect feature based on the laser scanning three-dimensional image; wherein the second defect feature is a concave feature formed by the uncompacted surface of the spherical protrusion 113; The third control module is used to control the completion of the supplementary compaction operation on the spherical protrusion 113, and return to the top view of the cylindrical mold 121 to obtain the laser scanning three-dimensional image of the inverted conical hole 112 and the spherical protrusion 113; if not, control the completion of the thermal deformation treatment of the second embryo 170 to obtain the neodymium iron boron magnet 110.

[0038] The relevant explanations and examples of each module in the system of this embodiment can refer to the methods of the aforementioned embodiments and will not be repeated here.

[0039] Example 3: Based on the same inventive concept as the above embodiment, this embodiment provides a computer device, which includes a memory and a processor. The memory stores a computer program, and the processor executes the computer program to implement the above method.

[0040] Example 4: Based on the same inventive concept as the above embodiment, this embodiment provides a computer-readable storage medium, on which a computer program is stored. A processor executes the computer program to implement the above method.

[0041] The above are only preferred embodiments of the present application and do not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A method for controlling the preparation of NdFeB magnets, characterized in that: The following steps are involved: A pre-compacting operation of the NdFeB magnetic powder is completed based on control of a custom mold to form a first embryonic body. The custom mold includes a cylindrical mold having a cavity. A plurality of core rods are movably provided through the side wall of the cylindrical mold. The core rods extend into the cavity and are used to form blind holes in the side wall of the first embryonic body. Obtain the blind hole depth image after the core rod is extracted based on the side view of the barrel mold; Identify whether the blind hole has a first defect feature based on the blind hole depth image; wherein the first defect feature is a concave feature formed by the uncompacted hole end surface of the blind hole; If so, the control is to complete the additional compaction operation of the blind hole after the mandrel is installed, and return to the perspective facing the side wall of the barrel mold to obtain the blind hole depth image after the mandrel is removed; if not, the control is to complete the hole-making operation of the first embryonic body to form a second embryonic body; wherein the second embryonic body has an inverted tapered hole on the top and a spherical protrusion on the bottom of the inverted tapered hole; The laser scanning 3D images of the inverted tapered hole and spherical protrusion are obtained based on the top view of the cylinder mold; Identify whether the spherical protrusion has a second defect feature based on the laser scanning three-dimensional image; wherein the second defect feature is a concave feature formed by the uncompacted surface of the spherical protrusion; If so, the control is to complete the supplementary compaction operation on the spherical protrusion, and return to the top view based on the cylindrical mold to obtain the laser scanning three-dimensional image of the inverted conical hole and the spherical protrusion; if not, the control is to complete the thermal deformation treatment of the second embryo to obtain the neodymium iron boron magnet.

2. A method for controlling the preparation of NdFeB magnets according to claim 1, characterized in that: Identify whether the blind hole has the first defect feature based on the blind hole depth image, including: Obtaining depth values of a plurality of pixel points corresponding to the end surface of the blind hole according to the blind hole depth image; Get the maximum value of the depth values of multiple pixels; Determine whether the maximum value is greater than a preset first depth threshold; if so, identify the presence of a first defect feature in the blind hole; if not, select target pixels having a depth value greater than a preset second depth threshold; wherein the second depth threshold is less than the first depth threshold; Obtain an average value h of the depth values corresponding to the multiple target pixels and the number n of the multiple target pixels; Get the first defect value Q; where Q=n h; It is determined whether the first defect value Q is greater than a preset defect threshold value. If so, it is determined that the blind hole has the first defect feature. If not, it is determined that the blind hole does not have the first defect feature.

3. A method for controlling the preparation of NdFeB magnets according to claim 1, characterized in that: Based on the laser scanning 3D image, identify whether the spherical protrusion has a second defect feature, including: Constructing a three-dimensional coordinate system based on the laser scanning three-dimensional image; wherein the coordinate origin of the three-dimensional coordinate system is located on the axis line of the spherical convexity; Based on the three-dimensional coordinate system, obtain the vertex coordinates of the spherical protrusion; Compare the vertex coordinates with the theoretical coordinates to obtain the z-axis coordinate difference; wherein the theoretical coordinates are the coordinate positions of the vertex of the spherical protrusion when there is no depression; Determine whether the z-axis coordinate difference is greater than a preset first threshold value. If so, identify the presence of a second defect feature in the spherical protrusion. If not, obtain reference coordinates of the inner wall of the inverted tapered hole at different positions; wherein the reference coordinates are lower than the vertex coordinates. Obtaining associated coordinates corresponding to the surface of the spherical convex surface and the reference coordinates; wherein the z-coordinate values of the associated coordinates and the reference coordinates are equal, and a line connecting the associated coordinates and the reference coordinates passes through the axis of the spherical convex surface; Get the coordinate distance value between the associated coordinate and the reference coordinate; It is determined whether the coordinate distance value is greater than a preset second threshold value. If so, it is identified that the spherical protrusion has the second defect feature. If not, it is identified that the spherical protrusion does not have the second defect feature.

4. A method for controlling the preparation of NdFeB magnets as claimed in claim 3, characterized in that: Obtain the reference coordinates of the inner wall of the inverted tapered hole at different positions, including: A plurality of discrete first reference coordinates are selected around a first height position of the inner wall of the inverted tapered hole; wherein the first height position is lower than the vertex coordinate of the spherical protrusion; If the coordinate distance between the first reference coordinate and the corresponding associated coordinate is less than or equal to the corresponding second threshold, a plurality of discrete second reference coordinates are selected around a second height position of the inner wall of the inverted tapered hole; wherein the second height position is lower than the first height position; If the coordinate distance between the second reference coordinate and the corresponding associated coordinate is less than or equal to the corresponding second threshold, a plurality of discrete third reference coordinates are selected around a third height position of the inner wall of the inverted tapered hole; wherein the third height position is lower than the second height position; Until the end condition is reached; wherein, the end condition is that the current reference coordinate reaches a preset minimum height position or the coordinate distance value between the current reference coordinate and the corresponding associated coordinate is greater than the corresponding second threshold.

5. The method for controlling the preparation of NdFeB magnets according to claim 1, wherein: Controls the additional compaction of blind holes after the mandrel is installed, including: Controlling the first hydraulic component to press into the first embryonic body to form a filling hole in the middle of the first embryonic body; wherein the first hydraulic component includes a first hydraulic plate, a core column for forming the filling hole is connected to the bottom of the first hydraulic plate, and the bottom of the filling hole is lower than the position of the blind hole; The filling hole is controlled to be filled with NdFeB magnetic powder, and the second hydraulic plate is controlled to compact the filled first embryonic body to complete the supplementary compaction operation of the blind hole.

6. A method for controlling the preparation of NdFeB magnets according to claim 1, characterized in that: Controlling and completing a hole-making operation on the first embryonic body to form a second embryonic body includes: The second hydraulic component is controlled to be pressed into the first embryo to form a second embryo; wherein the second hydraulic component includes a third hydraulic plate, the bottom of the third hydraulic plate is connected to an inverted conical column, and the bottom of the inverted conical column is provided with an inner groove for forming a spherical protrusion.

7. A method for controlling the preparation of NdFeB magnets according to claim 6, characterized in that: Control and complete the supplementary compaction operation on the spherical convexity, including: Controlling the addition of a corresponding amount of NdFeB magnetic powder to the raised area of the spherical surface; The second hydraulic component is controlled to press the second embryonic body into the spherical protrusion to complete the supplementary compaction operation on the spherical protrusion.

8. A neodymium iron boron magnet production control system, characterized in that: include: a first control module for controlling, based on a custom mold, pre-compacting the NdFeB magnetic powder to form a first embryonic body; wherein the custom mold comprises a cylindrical mold having a cavity, wherein a plurality of core rods are movably disposed through a side wall of the cylindrical mold, the core rods extending into the cavity and used to form blind holes in the side wall of the first embryonic body; The first image acquisition module is used to acquire a blind hole depth image after the core rod is extracted based on a side view of the barrel mold; A first defect recognition module is configured to identify whether the blind hole has a first defect feature based on the blind hole depth image; wherein the first defect feature is a concave feature formed by an uncompacted hole end surface of the blind hole; A second control module is configured to, if yes, control the completion of the additional compaction operation on the blind hole after the mandrel is installed, and return to the state of obtaining a blind hole depth image after the mandrel is removed based on a perspective facing the side wall of the barrel mold; if no, control the completion of the hole forming operation on the first embryonic body to form a second embryonic body; wherein the second embryonic body has an inverted tapered hole on the top and a spherical protrusion on the bottom of the inverted tapered hole; The second image acquisition module is used to acquire a laser scanning three-dimensional image of the inverted tapered hole and the spherical protrusion based on a top-down perspective of the cylindrical mold; A second defect recognition module is used to identify whether the spherical protrusion has a second defect feature based on the laser scanning three-dimensional image; wherein the second defect feature is a concave feature formed by the uncompacted surface of the spherical protrusion; The third control module is used to control the completion of the supplementary compaction operation on the spherical protrusion and return to the top view of the cylinder mold to obtain the laser scanning three-dimensional image of the inverted conical hole and the spherical protrusion; if not, control the completion of the thermal deformation treatment of the second embryo to obtain the neodymium iron boron magnet.

9. A computer device, characterized in that: The computer device includes a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the method according to any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that The computer-readable storage medium stores a computer program, and the processor executes the computer program to implement the method according to any one of claims 1 to 7.

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