A method for inspecting invisible cracks in permanent ferrite magnetic tile green body

Abstract

The present invention discloses a method for inspecting invisible cracks in green sheets of permanent ferrite magnet tiles, comprising the following steps: Step 1, developing treatment, developing treatment is performed on the green sheets, and the green sheets with invisible dark cracks have linear crack boundaries, and the green sheets without invisible dark cracks are in a disordered natural state, and the present invention relates to the technical field of wet-pressed permanent ferrite magnet tile production process. The method for inspecting invisible cracks in green sheets of permanent ferrite magnet tiles can timely, quickly and accurately detect whether there are invisible cracks in the green sheets by spraying paint or immersing the green sheets in oil, avoiding the destructive test of breaking the green sheets for inspection and the hysteresis of trial firing and polishing, thereby improving efficiency and reducing waste.

Description

Technical Field

[0001] The invention relates to the technical field of permanent ferrite wet pressed magnetic tile production process, in particular to a method for inspecting invisible cracks in permanent ferrite magnetic tile green bodies. Background Art

[0002] Permanent ferrite magnetic tiles are pressed into green bodies by hydraulic presses through a fixed mold, sintered at high temperature into semi-finished products, and then ground into finished products by special grinders.

[0003] Permanent ferrite magnets are made of powder metallurgy and are hard and brittle. They are installed in various DC micro motors to provide magnetic fields. Therefore, in addition to the requirements for magnetic properties, there are also strict requirements for mechanical strength. Cracks in magnet products will lead to poor mechanical strength and easy breakage when installed.

[0004] Cracks in magnetic tiles are usually divided into visible cracks and invisible cracks, which are mainly caused by differences in the density of the green molded products. Products with large density differences are prone to visible cracks, which can be visually found on the green molded products, are easy to identify, and can be solved in time through debugging; products with relatively small green molded products are prone to invisible cracks, which are invisible to the eye and difficult to find and identify. After sintering and grinding, the finished products produced have poor mechanical strength due to invisible cracks, and the products are unqualified, resulting in waste.

[0005] The traditional method of inspecting invisible cracks in magnetic tiles is to break the green body (i.e. destructive testing), and judge whether invisible cracks exist based on the cross-sectional morphology based on experience, which is both wasteful and carries the risk of misjudgment; or to conduct final inspection by trial-firing and polishing samples, but due to the continuity of large-scale production, judgment is delayed. Summary of the invention

[0006] In view of the deficiencies in the prior art, the present invention provides a method for inspecting invisible cracks in a permanent magnet ferrite magnetic tile green body, thereby solving the above-mentioned problems.

[0007] To achieve the above objectives, the present invention is implemented by the following technical solutions: A method for inspecting invisible cracks in a permanent magnet ferrite magnetic tile green body, comprising the following steps:

[0008] Step 1: developing the green body, where the green body with invisible dark cracks has linear crack boundaries, and the green body without invisible dark cracks is in a disordered natural state;

[0009] Step 2: Visual observation: Use visual methods to check the linear crack boundaries existing on the green body paint or oil medium surface;

[0010] Step three, subsequent cleaning, clean the surface of the green body, and transport it through the feed conveyor belt in the detection equipment. At this time, fill the water tank with water, and the feed conveyor belt transports the green body to the water tank to be cleaned by water. At this time, the fan supplies air to the upper blowing chamber and the overflow blowing chamber through the aeration pipe, and blows up the attachments on the surface of the green body through the upper blowing chamber to make it suspended on the water surface, and then blows the attachments into the connecting pipe through the overflow blowing chamber, and transports it to the overflow box for collection, and then transports the green body through the guide frame, guides it through the guide wheel, drives the friction wheel driven by the drive motor to transport the green body at intervals, and then receives it through the limit plate on the surface of the discharge conveyor belt, and then transports the green body to the drying box, and uses the fan to discharge air from the air pipe, and blows it out from the mesh plate after being heated by the electric heater to dry the green body, and then outputs to complete the detection.

[0011] As a further solution of the present invention: when the development treatment is carried out by spray paint in the step one, the material is transported through a feed conveyor belt on the surface of the detection equipment, and then the surface of the green body is sprayed with paint by a spraying device above the feed conveyor belt, and the outer surface of the green body is sprayed with colored spray paint.

[0012] As a further solution of the present invention: when the development treatment in step 2 is performed by spray paint, visual inspection shows that invisible dark cracks will have linear crack boundaries, and the parts without cracks are in a disorderly natural state of the spray paint.

[0013] As a further solution of the present invention: when the development process is performed by spray painting, the paint is a specific color, the specific color is a colored paint other than gray and black, and the painting method is uniform spraying.

[0014] As a further scheme of the present invention: when the development treatment is carried out in the step one by infiltration with the infiltration oil, the raw billets are transported through the feed conveyor belt in the detection equipment. At this time, the water tank is filled with the infiltration oil. The feed conveyor belt transports the raw billets into the water tank to be infiltrated with the infiltration oil. The raw billets are then transported through the guide frame, guided by the guide wheel, and driven by the driving motor to drive the friction wheel to transport the raw billets at intervals. The billets are then received by the limit plate on the surface of the discharge conveyor belt. The raw billets are then transported to the drying box, and the air is discharged from the air duct by the fan. After being heated by the electric heater, they are blown out from the mesh plate to simulate drying of the raw billets and output.

[0015] As a further solution of the present invention: when the development treatment in step 2 is performed by infiltration with immersion oil, there will be linear crack boundaries where there are invisible dark cracks, and the part without cracks is a disorderly natural state where the infiltration oil adheres to the green body.

[0016] As a further solution of the present invention: the feed conveyor belt and the guide frame are arranged in parallel, and are both arranged perpendicular to the discharge conveyor belt.

[0017] The detection equipment includes a water tank, a feed conveyor belt and a discharge conveyor belt. The left side of the water tank is fixedly connected to an overflow box. One end of the feed conveyor belt and the discharge conveyor belt penetrates and extends to the inner cavity of the water tank. The feed conveyor belt and the discharge conveyor belt are connected through a guide frame. The inner cavity of the guide frame is rotatably connected to a guide wheel and a friction wheel respectively. One side of the guide frame is fixedly connected to a driving motor for driving the friction wheel to rotate. The surface of the discharge conveyor belt is fixedly connected to a limit plate. The angle of the guide frame is parallel to the angle of the limit plate. The top of the water tank is fixedly connected to a fan. The air outlet of the fan is respectively connected to an air blowing pipe and an aeration pipe. One end of the aeration pipe extends to the inner cavity of the water tank, and one end of the aeration pipe located in the inner cavity of the water tank is respectively connected with an upper blowing cavity and an overflow blowing cavity, the upper blowing cavity blows the paint or impregnation oil attached to the ferrite to the upper side, and then blows it out through the overflow blowing cavity, one side of the water tank is connected with the inner cavity of the overflow box through a connecting pipe, a drainage pipe is provided at the bottom of the overflow box, a drying box is provided on the surface of the discharging conveyor belt, one end of the air blowing pipe is connected with the inner cavity of the drying box, a mesh plate is fixedly connected to the inner cavity of the drying box, an electric heater is fixedly connected to the inner cavity of the mesh plate, and an air outlet facing the discharging conveyor belt is provided on the surface of the mesh plate.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] 1. The present invention can timely, quickly and accurately detect whether the green tile has invisible cracks by means of paint spraying or oil immersion, thus avoiding the destructive test of breaking the green tile for inspection and the hysteresis of trial firing and polishing, thereby improving efficiency and reducing waste.

[0020] 2. The present invention can perform two types of detection through dedicated detection equipment, and can quickly clean the green body after detection. A single device can complete multiple processes and play a multi-functional role, which speeds up the detection process and saves detection costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a structural schematic diagram of the detection device of the present invention;

[0022] Figure 2 It is a structural cross-sectional view of the detection device of the present invention;

[0023] Figure 3 For the present invention Figure 2 A partial enlarged view of the middle A;

[0024] Figure 4 For the present invention Figure 2 A partial enlarged view of point B in the middle;

[0025] Figure 5 It is a structural schematic diagram of the guide frame of the present invention;

[0026] Figure 6 This is a result diagram of checking invisible cracks in permanent magnet ferrite green body according to the present invention.

[0027] In the figure: 1. water storage tank; 2. overflow box; 3. feed conveyor belt; 4. discharge conveyor belt; 5. guide frame; 6. upper blowing chamber; 7. fan; 8. aeration pipe; 9. overflow blowing chamber; 11. connecting pipe; 12. drainage pipe; 13. limit plate; 14. drying box; 15. air blowing pipe; 16. mesh plate; 17. electric heater; 18. guide wheel; 19. friction wheel; 20. drive motor. DETAILED DESCRIPTION

[0028] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the specific implementation mode, structure, characteristics and effects of the present invention are described in detail below in combination with the accompanying drawings and preferred embodiments.

[0029] See also Figure 1-6 , the present invention provides the following two embodiments:

[0030] Embodiment 1

[0031] A method for inspecting invisible cracks in a permanent magnet ferrite green tile comprises the following steps:

[0032] Step 1, development treatment, developing treatment is performed on the green body, the green body is a permanent magnet ferrite magnetic tile green body, when developing by spray painting, it is conveyed by the feed conveyor belt 3 on the surface of the detection equipment, and then the surface of the green body is sprayed with paint by the spraying equipment above the feed conveyor belt 3, and the outer surface of the green body is sprayed with colored spray paint. Visual inspection shows that there are invisible dark cracks with linear crack boundaries, and the part without cracks is a disorderly natural state of spraying the spray paint. When the development treatment is performed by spray painting, the paint is a specific color, and the specific color is a colored paint other than gray and black, and the painting method is uniform spraying;

[0033] Step 2: Visual observation: Use visual method to check the linear crack boundary existing on the green paint medium surface;

[0034] Step 3, subsequent cleaning, clean the surface of the green body, and transport it through the feed conveyor belt 3 in the detection equipment. At this time, fill the water storage tank 1 with water, and the feed conveyor belt 3 transports the green body to the water storage tank 1 to be cleaned by water. At this time, the fan 7 supplies air to the upper blowing chamber 6 and the overflow blowing chamber 9 through the aeration pipe 8, and blows up the attachments on the surface of the green body through the upper blowing chamber 6 to make it suspended on the water surface, and then blows the attachments into the connecting pipe 11 through the overflow blowing chamber 9, and transports it to the overflow box 2 for collection, and then transports the green body through the guide frame 5, guides it through the guide wheel 18, and drives the friction wheel 19 to move the green body between the guide frame 5 and the guide wheel 18. The green body is transported in intervals, and then received by the limit plate 13 on the surface of the discharging conveyor belt 4, and then transported to the drying box 14, and the air is discharged from the air duct 15 by the fan 7. After being heated by the electric heater 17, it is blown out from the mesh plate 16 to dry the green body, and then output to complete the inspection. By evenly spraying the outer surface of the green body with colored spray paint, clear linear crack boundaries will immediately appear if there are invisible dark cracks, while the part without cracks is a disorderly natural state of spraying the spray paint; the gap of the green body invisible crack that is difficult to find visually is very small, and the sprayed paint cannot enter the gap, and clear linear cracks can be seen on the interface of the sprayed paint.

[0035] Embodiment 2

[0036] A method for inspecting invisible cracks in a permanent magnet ferrite green tile comprises the following steps:

[0037] Step 1, development treatment, the green blank is developed, the green blank is a permanent magnet ferrite magnetic tile green blank, when it is developed by infiltration with infiltration oil, the infiltration oil is kerosene or diesel, and it is transported by the feed conveyor belt 3 in the detection equipment, at this time, the water storage tank 1 is filled with infiltration oil, the feed conveyor belt 3 transports the green blank to the water storage tank 1 to be infiltrated with the infiltration oil, and then the green blank is transported by the guide frame 5, guided by the guide wheel 18, and driven by the drive motor 20 to drive the friction wheel 19 to transport the green blank at intervals, and then it is received by the limit plate 13 on the surface of the discharge conveyor belt 4, and then the green blank is transported to the drying box 14, and the air blower 7 is used to discharge the air duct 15, and after being heated by the electric heater 17, it is blown out from the mesh plate 16 to simulate the drying of the green blank, and output, when it is developed by infiltration with infiltration oil, there will be invisible dark cracks with linear crack boundaries, and the part without cracks is the natural state of the infiltration oil adhering to the green blank in a disorderly manner;

[0038] Step 2: Visual observation: Use visual method to check the linear crack boundary existing on the surface of the green body infiltrated with oil medium;

[0039] Step three, subsequent cleaning, clean the surface of the green body, and transport it through the feed conveyor belt 3 in the detection equipment. At this time, fill the water storage tank 1 with water, and the feed conveyor belt 3 transports the green body to the water storage tank 1 to be cleaned by water. At this time, the fan 7 supplies air to the upper blowing chamber 6 and the overflow blowing chamber 9 through the aeration pipe 8, and blows up the attachments on the surface of the green body through the upper blowing chamber 6 to make it suspended on the water surface, and then blows the attachments into the connecting pipe 11 through the overflow blowing chamber 9, and transports it to the overflow box 2 for collection, and then transports the green body through the guide frame 5, guides it through the guide wheel 18, drives the driving friction wheel 19 through the drive motor 20 to transport the green body at intervals, and then supports it through the limit plate 13 on the surface of the discharge conveyor belt 4. Then, the green body is transported to the drying box 14, and the air is discharged from the air duct 15 through the fan 7. After being heated by the electric heater 17, the green body is blown out from the mesh plate 16 to dry the green body, and then output to complete the inspection. The green body is soaked with impregnating oil and then taken out. During the drying process, clear linear crack boundaries will immediately appear in the invisible dark cracks, while the parts without cracks are in a disorderly natural state where the impregnating oil adheres to the green body. The gaps of the invisible cracks of the green body that are difficult to find visually are very small. When the green body soaked with impregnating oil is taken out and dried, the surface of the green body is pressed densely and smoothly, the impregnating oil attached to the interface without cracks is moist and shiny, and the oil enters the crack gaps in the parts with invisible cracks, and clear linear cracks can be seen on this interface.

[0040] The detection equipment includes a water storage tank 1, a feed conveyor belt 3 and a discharge conveyor belt 4. The left side of the water storage tank 1 is fixedly connected with an overflow box 2. One end of the feed conveyor belt 3 and the discharge conveyor belt 4 penetrates and extends to the inner cavity of the water storage tank 1. The feed conveyor belt 3 and the discharge conveyor belt 4 are connected through a guide frame 5. The inner cavity of the guide frame 5 is rotatably connected with a guide wheel 18 and a friction wheel 19 respectively. One side of the guide frame 5 is fixedly connected with a driving motor 20 for driving the friction wheel 19 to rotate. The surface of the discharge conveyor belt 4 is fixedly connected with a limit plate 13. The angle of the guide frame 5 is parallel to the angle of the limit plate 13. The top of the water storage tank 1 is fixedly connected with a fan 7. The air outlet of the fan 7 is respectively connected with an air blast pipe 15 and an aeration pipe 8. The aeration One end of the pipe 8 extends to the inner cavity of the water tank 1. The aeration pipe 8 is located at one end of the inner cavity of the water tank 1 and is connected to an upper blowing cavity 6 and an overflow blowing cavity 9 respectively. The upper blowing cavity 6 blows the paint or impregnation oil attached to the ferrite to the upper side, and then blows it out through the overflow blowing cavity 9. One side of the water tank 1 is connected to the inner cavity of the overflow box 2 through a connecting pipe 11. A drainage pipe 12 is provided at the bottom of the overflow box 2. A drying box 14 is provided on the surface of the discharge conveyor belt 4. One end of the air blowing pipe 15 is connected to the inner cavity of the drying box 14. A mesh plate 16 is fixedly connected to the inner cavity of the drying box 14. An electric heater 17 is fixedly connected to the inner cavity of the mesh plate 16. An air outlet facing the discharge conveyor belt 4 is provided on the surface of the mesh plate 16.

[0041] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technical personnel in this field can make some changes or modify the technical contents disclosed above into equivalent embodiments without departing from the scope of the technical solution of the present invention. However, any brief modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A method for inspecting invisible cracks in permanent ferrite magnetic tiles, characterized in that: The following steps are involved: Step 1: developing the green body, wherein the green body with invisible dark cracks has a linear crack boundary, and the green body without invisible dark cracks is in a natural state; When the development treatment is performed in the step 1 by infiltration with the infiltration oil, the green body is conveyed through the feed conveyor belt (3) in the detection device. At this time, the water storage tank (1) is filled with the infiltration oil. The feed conveyor belt (3) conveys the green body to the water storage tank (1) to be infiltrated with the infiltration oil. The green body is then conveyed through the guide frame (5), guided by the guide wheel (18), driven by the drive motor (20) to drive the friction wheel (19) to convey the green body in intervals, and then received by the limit plate (13) on the surface of the discharge conveyor belt (4). The green body is then conveyed to the drying box (14), and air is discharged from the air blast pipe (15) by the fan (7). After being heated by the electric heater (17), the green body is blown out from the mesh plate (16) to simulate drying and output; Step 2: Visual observation: Use visual methods to check the linear crack boundaries existing on the green body paint or oil medium surface; Step 3: subsequent cleaning: the surface of the green body is cleaned and transported through the feed conveyor belt (3) in the detection equipment. At this time, the water storage tank (1) is filled with water, and the feed conveyor belt (3) transports the green body to the water storage tank (1) to be cleaned by water. At this time, the fan (7) supplies air to the upper blowing chamber (6) and the overflow blowing chamber (9) through the aeration pipe (8), and the attached matter on the surface of the green body is blown up through the upper blowing chamber (6) to make it suspended on the water surface, and then the attached matter is blown into the connecting pipe (11) through the overflow blowing chamber (9) and transported to The green pieces are collected in an overflow box (2), then conveyed by a guide frame (5), guided by a guide wheel (18), and conveyed at intervals by a driving motor (20) driving a driving friction wheel (19), and then received by a limit plate (13) on the surface of a discharge conveyor belt (4), and then conveyed to a drying box (14), and blown out of an air blast pipe (15) by a fan (7), and then heated by an electric heater (17) and blown out from a mesh plate (16) to dry the green pieces, and then output for inspection.

2. A method for inspecting invisible cracks in a permanent magnet ferrite green tile according to claim 1, characterized in that: When the development treatment is performed by spray paint in step 1, the material is transported through the feed conveyor belt (3) on the surface of the detection device, and then the surface of the green body is sprayed with paint by the spraying equipment above the feed conveyor belt (3), and the outer surface of the green body is completely sprayed with colored spray paint.

3. A method for inspecting invisible cracks in a permanent magnet ferrite green tile according to claim 2, characterized in that: When developing by spray paint in the step 2, invisible dark cracks will show linear crack boundaries upon visual inspection, while the parts without cracks are in a disorderly natural state of the spray paint.

4. The method for inspecting invisible cracks in permanent magnet ferrite green tiles according to claim 2, characterized in that: When the development process is performed by spray painting, the paint is a specific color and the painting method is uniform spraying.

5. The method for inspecting invisible cracks in permanent magnet ferrite green tiles according to claim 1, characterized in that: When the development is performed by infiltration with immersion oil in the step 2, invisible dark cracks will have linear crack boundaries, and the parts without cracks are in a disorderly natural state where the infiltration oil adheres to the green body.

6. The method for inspecting invisible cracks in permanent magnet ferrite green tiles according to claim 1, characterized in that: The feed conveyor belt (3) and the guide frame (5) are arranged in parallel, and are both arranged perpendicular to the discharge conveyor belt (4).

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