A thermostatic pressing and molding equipment for pressed magnetic cores

Abstract

This application relates to the field of power grid equipment manufacturing technology, specifically disclosing a thermostatic pressing molding device for pressed magnetic cores. The device includes a machine body, a rotating shaft, a mold plate, an upper die, a lower die, a guide plate, a feeding hopper, and a feeding pipe. The mold plate has multiple material slots adapted to the upper and lower dies. A mounting frame is fixed to the outside of the mold plate. A limit frame is fixed to the mounting frame, and a conveyor belt is installed within the limit frame. Multiple coils are installed on the conveyor belt. A temperature control component for controlling the temperature of the material slot walls is installed inside the mold plate. Two guide rods are fixed to the mounting frame, and brushes are fixed to the coils. A feeding frame is fixed to the mounting frame. A temporary storage box is fixed to the end of the feeding frame away from the feeding pipe. A downward-sloping shovel is fixed to the top of the temporary storage box near the feeding pipe. A suction component for removing excess magnetic powder from the temporary storage box is installed on the machine body. This application improves the uniformity of material feeding and increases production efficiency during hot production.

Description

Technical Field

[0001] This application relates to the field of power grid equipment manufacturing technology, and in particular to a thermostatic pressing molding equipment for pressed magnetic cores. Background Technology

[0002] A magnetic core is a sintered magnetic metal oxide composed of various iron oxide mixtures, used in various power grid and electronic equipment such as coils, inductors, transformers, instrument transformers, and filters.

[0003] The pressing and molding of magnetic cores involves uniformly mixing magnetic powder coated with insulating material, binder, and release agent, sieving out agglomerates, and then pressing the mixture into various shapes of green blanks using a mold of a specific shape. There are various pressing methods for magnetic cores, including cold pressing, warm pressing, hot pressing, and multi-step pressing. There are many types of magnetic cores, including iron-silicon magnetic powder cores, iron-silicon-aluminum magnetic powder cores, and iron-nickel magnetic powder cores. The processing technology differs for different types of magnetic cores. For example, the optimal pressing temperature for iron-silicon magnetic powder cores is 150℃-200℃, and for iron-silicon-aluminum magnetic powder cores, it is 150℃-250℃. During the pressing process of iron-silicon magnetic powder cores, if the temperature is too low, the pressed core may lack strength and crack; if the temperature is too high, the resin coating may be burned, affecting performance stability.

[0004] There are various types of magnetic powder core pressing equipment, including single-shaft presses, multi-shaft presses, hot isostatic presses, and powder rotary presses. Among them, the powder rotary press has multiple stations for continuous production and combines modular functions such as powder feeding, pressing, demolding, and collection. Compared with other types of pressing equipment, the powder rotary press has higher production efficiency and automation.

[0005] Regarding the aforementioned technologies, the inventors believe that the following defects exist: When producing iron-silicon magnetic powder cores, although the powder rotary press has high production efficiency, it is difficult to press the magnetic powder at high temperatures; the single-shaft press is easy to modify to be suitable for high-temperature pressing, but its production efficiency is low. Moreover, whether it is a single-shaft press or a powder rotary press, during the feeding process, the feeding is easily affected by factors such as binders, resulting in uneven feeding and large gaps between magnetic powders, which in turn leads to a decrease in the stability of the subsequent finished products. Summary of the Invention

[0006] To address the issues of uneven magnetic powder distribution during the feeding process and low production efficiency during high-temperature pressing, this application provides a constant-temperature pressing molding device for pressed magnetic cores.

[0007] The constant temperature pressing and molding equipment for pressed magnetic cores provided in this application adopts the following technical solution:

[0008] A thermostatic pressing molding device for pressed magnetic cores includes a machine body, a rotating shaft rotatably mounted on the machine body, a mold plate fixed to the rotating shaft, an upper punch mounted on the rotating shaft above the mold plate, a lower punch mounted on the rotating shaft below the mold plate, a guide plate fixed to the machine body, a feeding hopper fixed to the machine body, and a feeding pipe connected to the feeding hopper. The mold plate has multiple material slots adapted to the upper and lower punches. The device is characterized by: a mounting frame fixed to the outside of the mold plate; a limiting frame adapted to the curvature of the mold plate; a conveyor belt within the limiting frame; multiple coils on the conveyor belt; the input and output ends of the coils fixed to the conveyor belt; the center of each coil aligned with the material slot of the mold plate, and their speeds being equal; and a temperature control component for controlling the temperature of the material slot wall within the mold plate.

[0009] Two guide rods are fixedly connected to the mounting bracket. Brushes are fixedly connected to both the input and output ends of the coil. When the conveyor belt drives the coil to move to a position close to the mold plate, the two brushes on the coil abut against the two guide rods respectively. The mold plate is made of non-magnetic stainless steel.

[0010] The mounting frame is fixedly connected to a feeding frame on the side of the feeding pipe away from the guide plate. The feeding frame is in contact with the mold plate. A temporary storage box is fixedly connected to the end of the feeding frame away from the feeding pipe. An inclined downward shovel is fixedly connected to the top of the temporary storage box near the end of the feeding pipe. The shovel is also in contact with the mold plate. The machine body is provided with a suction component for sucking up excess magnetic powder in the temporary storage box.

[0011] By adopting the above technical solution, the magnetic powder in the feeding hopper falls into the feeding frame through the feeding pipe. When the material trough on the mold plate moves to below the feeding frame, the magnetic powder stored in the feeding pipe and the feeding frame falls into the material trough. The coil is also conveyed by the conveyor belt to the top of the corresponding material trough and moves synchronously with it. At the same time, the brush on the coil is in close contact with the guide rod. The two guide rods provide alternating current to the coil, thereby causing the coil to generate an alternating magnetic field. The magnetic powder vibrates under the action of the changing magnetic field, causing the magnetic powder to adhere tightly to each other. At the same time, the magnetic powder also heats up due to eddy current phenomenon. When the coil moves to the point where the brush disengages from the guide rod, the coil stops heating the magnetic powder. At this time, the magnetic powder reaches the pressing temperature due to the heating of the coil, completing the feeding of one material trough and the heating of the magnetic powder in that trough. Magnetic powder fed into the mold tray in the feeding frame is shoveled into the temporary storage box by the shovel plate and then extracted by the suction component. As the mold tray continues to rotate, the heated magnetic powder is pressed into a magnetic core by the downward pressure of the upper punch. After pressing, the upper punch moves upward to reset, and the lower punch moves upward to eject the magnetic core. When the ejected magnetic core moves to the guide plate, it moves and is unloaded by the guide plate. Then the lower punch moves downward to reset. During the pressing process of the upper punch, the magnetic powder generates a lot of heat due to friction between the magnetic powder and the wall of the material tank. During long-term operation, the temperature control component controls the temperature of the material tank wall to avoid the temperature of the material tank wall being too high, which would affect the stability of the pressed magnetic core and the service life of the mold tray. In addition, multiple stations alternately perform feeding, heating, pressing, and unloading steps, resulting in high processing efficiency.

[0012] Optionally, the mold plate has multiple receiving slots around the wall of each of the material troughs, and the temperature control component includes a heat-conducting box placed in the receiving slot and a phase change layer filled in the heat-conducting box. The phase change layer is a ternary eutectic layer of sodium nitrate, potassium nitrate and sodium nitrite.

[0013] By adopting the above technical solution, the melting point of the phase change layer is adjusted by changing the ratio of sodium nitrate, potassium nitrate and sodium nitrite in the heat-conducting box, thereby adapting to the temperature range corresponding to different types of magnetic cores. During the magnetic powder pressing process, the temperature of the tank wall is transferred to the heat-conducting box and then to the phase change layer. When the temperature of the tank wall is high, the phase change layer melts and absorbs heat, keeping the tank wall at a constant temperature.

[0014] Optionally, the temperature control component further includes an air pipe formed in the peripheral wall of the heat conduction box, a one-way air valve disposed at one end of the air pipe, an elastic membrane disposed at the other end of the air pipe, and a control component for controlling the release of air from the elastic membrane. The one-way air valve only allows gas to flow from the heat conduction box into the air pipe. The air pipe is filled with nitrogen, and the one-way air valve is located at the top of the heat conduction box.

[0015] By adopting the above technical solution, when the gas pipe is continuously heated, the nitrogen gas inside the gas pipe expands and squeezes the elastic membrane. When the pressure inside the gas pipe is too high, the nitrogen gas pushes open the elastic membrane, causing the elastic membrane to break through the suppression of the control device, and then the nitrogen gas enters the heat-conducting box to generate bubbles. The molten phase change layer is affected by the disturbance of the bubbles and flows faster, thereby improving the heat exchange effect between the phase change layer and the side of the heat-conducting box close to the material tank. When the pressure inside the heat-conducting box is greater than that inside the gas pipe, the nitrogen gas enters the gas pipe again through the one-way gas valve. At the same time, due to the continuous pressing operation, changes in ambient temperature, melting of the phase change layer, and other factors, the temperature of the tank wall of the material tank always changes dynamically within the specified range. That is, the temperature inside the heat-conducting box and the gas pipe is also always in dynamic change, and the pressure difference between the gas pipe and the heat-conducting box is also in dynamic change.

[0016] Optionally, the control element is a spring steel sheet with one end fixed to the inner bottom wall of the heat conduction box. The elastic membrane is divided into an adhesive part and a bonding part. The adhesive part of the elastic membrane is seamlessly bonded to the inner wall of the heat conduction box, and the bonding part of the elastic membrane is bonded to the inner wall of the heat conduction box. The spring steel sheet presses the bonding part of the elastic membrane tightly.

[0017] By adopting the above technical solution, the elastic membrane bulges under the influence of air pressure, but the spring steel sheet presses down on the bonding part of the elastic membrane, causing the pressure inside the air pipe to increase until the pressure in the air pipe exceeds the restriction of the spring steel sheet on the elastic membrane. At this time, a gap appears between the bonding part of the elastic membrane and the inner wall of the heat conduction box, and nitrogen enters the phase change layer through the gap. At the same time, as the nitrogen is discharged from the air pipe, the spring steel sheet presses down on the elastic membrane again, completing one exhaust process.

[0018] Optionally, both the air inlet end of the one-way air valve and the end of the air pipe near the elastic membrane are fixedly connected to a filter plate that only allows gas to pass through.

[0019] By adopting the above technical solution, the filter plate prevents the molten phase change layer in the heat conduction box from entering the gas pipe through the elastic membrane end of the one-way valve and the gas pipe, thereby effectively preventing the phase change material from clogging the gas pipe and the one-way valve.

[0020] Optionally, the suction assembly includes a return pipe connected to the feeding hopper, a suction pipe connected to the return pipe, and a suction pipe connected to the suction pipe. The end of the suction pipe near the return pipe is tapered, and the connection between the suction pipe and the suction pipe is located at the tapered end of the suction pipe. The suction pipe is connected to the side wall of the temporary storage box, and an air source is connected to the suction pipe.

[0021] By adopting the above technical solution, when the suction tube draws in air, the airflow moves to the constriction point of the suction tube. Due to the reduction in the orifice diameter, the airflow velocity increases and the pressure decreases. That is, the pressure at the end of the suction tube near the suction tube is less than that at the end of the suction tube near the temporary storage box. At this time, the magnetic powder in the temporary storage box is drawn in by the suction tube. At the same time, the suction tube also draws in the magnetic powder remaining on the surface of the pressed magnetic core. Thus, the magnetic powder on the temporary storage box and the magnetic core is drawn to the return tube and finally fed into the feeding bucket through the return tube to avoid waste of magnetic powder. In addition, after the magnetic core is formed, the suction tube also performs a certain cooling treatment on the magnetic core, reducing the risk of workers being burned.

[0022] Optionally, the end of the return pipe near the feed hopper is connected to a mesh with a bottom opening.

[0023] By adopting the above technical solution, the magnetic powder ejected from the return pipe collides with the mesh, which reduces the speed of the magnetic powder, making it easier for the magnetic powder to fall to the bottom of the feeding hopper and preventing the high-speed magnetic powder from scattering everywhere.

[0024] Optionally, a silicon steel sheet is provided at one end of the coil near the middle of the conveyor belt.

[0025] By adopting the above technical solution, the silicon steel sheet effectively enhances the concentration and guidance of the magnetic field generated by the coil. That is, due to factors such as the global transmission of the magnetic field, the magnetic field at the end of the coil away from the silicon steel sheet also changes accordingly, which helps to guide the alternating magnetic field to the material tank, thereby reducing magnetic field leakage and enhancing the movement efficiency and heating speed of the magnetic powder.

[0026] Optionally, multiple partition bars with a height lower than the height of the feeding frame are fixed inside the feeding frame. The partition bars are arc-shaped, and the middle part of the partition bars is located on the movement path of the material trough.

[0027] By adopting the above technical solution, when the mold plate rotates, the magnetic powder located in the feeding frame and above the mold plate is scraped into the material trough by the separator strip. Combined with the slight vibration effect of the alternating magnetic field of the coil on the magnetic powder, the magnetic powder in the material trough is compacted and the surface is concave. Then, it is filled by the feeding of the next separator strip, thereby improving the final feeding effect of the material trough.

[0028] In summary, this application includes at least one of the following beneficial technical effects:

[0029] 1. When the feed trough and the coil move synchronously and in tandem, the brushes on the coil are in close contact with the guide rods. The two guide rods provide alternating current to the coil, which in turn causes the coil to generate an alternating magnetic field. The silicon steel sheet enhances the concentration and guidance of the magnetic field generated by the coil. The magnetic powder vibrates under the action of the changing magnetic field, causing the magnetic powder to adhere tightly to each other, improving the uniformity of the magnetic powder in the feed trough. At the same time, the magnetic powder also heats up due to the eddy current phenomenon, and the whole process has high processing efficiency.

[0030] 2. During the magnetic powder pressing process, the temperature of the tank wall is transferred to the heat-conducting box and then to the phase change layer. When the temperature of the tank wall is high, the phase change layer melts and absorbs heat. At the same time, the nitrogen in the gas pipe expands and squeezes the elastic membrane. When the pressure in the gas pipe is too high, the nitrogen pushes open the elastic membrane, allowing it to break through the spring steel sheet and enter the heat-conducting box to generate bubbles. The molten phase change layer is accelerated by the disturbance of the bubbles, effectively improving the heat exchange effect between the phase change layer and the side of the heat-conducting box close to the tank. When the pressure in the heat-conducting box is greater than that in the gas pipe, nitrogen enters the gas pipe through the one-way valve. At the same time, due to the continuous pressing operation and changes in ambient temperature, the temperature of the tank wall is always dynamically changing within the specified range. That is, the temperature of the heat-conducting box and the gas pipe are also always dynamically changing, and the pressure difference between the gas pipe and the heat-conducting box is also dynamically changing.

[0031] 3. During the process of the magnetic core being pressed and guided away from the mold plate by the guide plate, the suction tube sucks up the magnetic powder remaining on the surface of the magnetic core and reduces the temperature of the magnetic core. At the same time, excess magnetic powder in the temporary storage box is sucked back by the suction tube and eventually flows into the return pipe together with the magnetic powder sucked up by the suction tube, so as to reduce the waste of magnetic powder and reduce the accident rate of personnel being burned. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of the overall structure of an embodiment of this application;

[0033] Figure 2 It is along Figure 1 Schematic diagram of the cross-sectional structure along line AA;

[0034] Figure 3 yes Figure 2 Enlarged schematic diagram of part B;

[0035] Figure 4 yes Figure 2 An enlarged schematic diagram of section C;

[0036] Figure 5 yes Figure 1 An enlarged schematic diagram of section D in the middle;

[0037] Figure 6 This application is mainly used to show the structural diagrams of the feeding frame, temporary storage box, shovel plate, separator strip, rotating shaft, mold plate and material trough.

[0038] Reference numerals: 1. Machine body; 11. Rotating shaft; 12. Mold plate; 121. Material trough; 122. Receiving trough; 13. Upper punch; 14. Lower punch; 15. Guide plate; 16. Feeding bucket; 17. Feeding pipe; 2. Mounting frame; 21. Limiting frame; 22. Conveyor belt; 23. Coil; 24. Guide rod; 25. Brush; 3. Temperature control component; 31. Heat conduction box; 32. Phase change layer; 33. Air pipe; 34. One-way air valve; 35. Elastic membrane; 36. Spring steel sheet; 41. Feeding frame; 42. Temporary storage box; 43. Shovel plate; 44. Separator strip; 5. Suction component; 51. Return pipe; 52. Suction pipe; 53. Suction pipe; 6. Filter plate; 7. Net; 8. Silicon steel sheet. Detailed Implementation

[0039] The following is in conjunction with the appendix Figure 1-6 This application will be described in further detail.

[0040] This application discloses a thermostatic pressing and molding apparatus for pressed magnetic cores. (Refer to...) Figure 1 , Figure 2 and Figure 3 The constant temperature pressing molding equipment for pressed magnetic cores includes a machine body 1, a rotating shaft 11 rotatably mounted on the machine body 1, a mold plate 12 fixed to the rotating shaft 11, an upper punch 13 lifted above the mold plate 12 on the rotating shaft 11, a lower punch 14 lifted below the mold plate 12 on the rotating shaft 11, a guide plate 15 fixed to the machine body 1, a feeding hopper 16 fixed to the machine body 1, and a feeding pipe 17 connected to the feeding hopper 16. The mold plate 12 has multiple material slots 121 adapted to the upper punch 13 and the lower punch 14. A mounting frame 2 is fixed to the outside of the mold plate 12 on the machine body 1. A limiting frame 21 adapted to the curvature of the mold plate 12 is fixed to the mounting frame 2. A conveyor belt 22 is installed inside the limiting frame 21. Multiple coils 23 are installed on the conveyor belt 22. The input and output ends of the coils 23 are fixed to the conveyor belt 22. The center of the coil 23 is aligned with the mold plate 12. The material troughs 121 of the mold plate 12 are aligned and their speeds are equal. A temperature control component 3 is installed inside the mold plate 12 to control the temperature of the trough wall of the material trough 121. Two guide rods 24 are fixedly connected to the mounting bracket 2. Brushes 25 are fixedly connected to both the input and output ends of the coil 23. When the conveyor belt 22 drives the coil 23 to a position close to the mold plate 12, the two brushes 25 on the coil 23 abut against the two guide rods 24 respectively. The mold plate 12 is free of... Magnetic stainless steel; the mounting frame 2 is fixedly connected to the side of the feeding pipe 17 away from the guide plate 15 with a feeding frame 41, the feeding frame 41 is in contact with the mold plate 12, the end of the feeding frame 41 away from the feeding pipe 17 is fixedly connected to a temporary storage box 42, the top of the temporary storage box 42 near the end of the feeding pipe 17 is fixedly connected to an inclined downward shovel plate 43, the shovel plate 43 is also in contact with the mold plate 12, and the machine body 1 is provided with a suction component 5 for suctioning excess magnetic powder in the temporary storage box 42.

[0041] The magnetic powder in the feeding hopper 16 falls into the loading frame 41 through the feeding pipe 17. When the material trough 121 on the mold plate 12 moves below the loading frame 41, the magnetic powder stored in the feeding pipe 17 and the loading frame 41 falls into the material trough 121. The coil 23 is also conveyed by the conveyor belt 22 to the area above the material trough 121 and moves synchronously with the corresponding material trough 121. At the same time, the brush 25 on the coil 23 is in close contact with the guide rod 24. The two guide rods 24 provide alternating current to the coil 23, thereby causing the coil 23 to generate an alternating magnetic field. The magnetic powder vibrates under the action of the changing magnetic field, causing the magnetic powder to adhere tightly to each other. At the same time, the magnetic powder also heats up due to eddy current phenomenon. When the coil 23 moves to the point where the brush 25 disengages from the guide rod 24, the coil 23 stops heating the magnetic powder. At this time, the magnetic powder reaches the pressing temperature due to the heating of the coil 23, completing one material trough. The feeding of magnetic powder into the material trough 121 and the heating of the magnetic powder in the material trough 121 are carried out. At this time, the magnetic powder conveyed by the mold plate 12 in the feeding frame 41 is shoveled into the temporary storage box 42 by the shovel plate 43 and then extracted by the suction component 5. As the mold plate 12 continues to rotate, the heated magnetic powder is pressed into a magnetic core by the downward pressure of the upper punch 13. After pressing, the upper punch 13 moves up and resets, and the lower punch 14 moves up to push out the magnetic core. When the pushed-out magnetic core moves to the guide plate 15, the magnetic core moves and is unloaded by the guidance of the guide plate 15. Then the lower punch 14 moves down and resets. During the pressing process of the upper punch 13, the magnetic powder and the groove wall of the material trough 121 will generate a lot of heat due to friction. During long-term operation, the temperature control component 3 controls the temperature of the groove wall of the material trough 121 to avoid the groove wall temperature of the material trough 121 being too high, which will affect the stability of the pressed magnetic core and the service life of the mold plate 12.

[0042] Reference Figure 2 and Figure 4The mold plate 12 has multiple receiving slots 122 around the wall of each material tank 121. The temperature control component 3 includes a heat-conducting box 31 placed in the receiving slot 122 and a phase change layer 32 filled in the heat-conducting box 31. The phase change layer 32 can be a ternary eutectic layer of sodium nitrate, potassium nitrate and sodium nitrite, or sebacic acid and its composite material or other phase change materials. In this application, the phase change layer 32 is a ternary eutectic layer of sodium nitrate, potassium nitrate and sodium nitrite. The temperature control component 3 also includes an air pipe 33 formed in the peripheral wall of the heat conduction box 31, a one-way air valve 34 set at one end of the air pipe 33, an elastic membrane 35 set at the other end of the air pipe 33, and a control component for controlling the release of air from the elastic membrane 35. The one-way air valve 34 only allows gas to flow from the heat conduction box 31 into the air pipe 33, and the one-way air valve 34 is located at the top of the heat conduction box 31. The air pipe 33 is filled with nitrogen or inert gas. In this application, the gas in the air pipe 33 is nitrogen. A heat conduction rod is also fixedly connected to the air pipe 33 at the bottom. The bottom of the heat conduction box 31 is made of thick high-strength steel. The heat conduction box 31 is connected to the mold plate 12 by countersunk bolts to reduce the impact of the heat conduction box 31 on the strength of the mold plate 12, and at the same time facilitate the maintenance of the heat conduction box 31.

[0043] The melting point of the phase change layer 32 is adjusted by regulating the ratio of sodium nitrate, potassium nitrate and sodium nitrite in the heat-conducting box 31, thereby adapting to the temperature range corresponding to different types of magnetic cores. During the magnetic powder pressing process, the temperature of the tank wall of the material tank 121 is transferred to the heat-conducting box 31 and then transferred from the heat-conducting box 31 to the phase change layer 32. When the temperature of the tank wall of the material tank 121 is high, the phase change layer 32 melts and absorbs heat, so that the tank wall of the material tank 121 is always in a constant temperature state. Furthermore, when the gas pipe 33 is continuously heated, the nitrogen gas inside the gas pipe 33 expands and squeezes the elastic membrane 35. When the pressure inside the gas pipe 33 is too high, the nitrogen gas pushes open the elastic membrane 35, causing the elastic membrane 35 to break through the suppression of the control element, thereby allowing the nitrogen gas to enter the heat-conducting box 31 and generate bubbles. The molten phase change layer 32 is affected by the disturbance of the bubbles and flows faster, thereby improving the heat exchange effect between the phase change layer 32 and the side of the heat-conducting box 31 close to the material tank 121. When the pressure inside the heat-conducting box 31 is greater than that inside the gas pipe 33, the nitrogen gas enters the gas pipe 33 again from the one-way gas valve 34. At the same time, due to the continuous pressing operation, changes in ambient temperature, melting of the phase change layer 32, etc., the temperature of the tank wall of the material tank 121 is always dynamically changing within the specified range. That is, the temperature inside the heat-conducting box 31 and the gas pipe 33 is also always dynamically changing, and the pressure difference between the gas pipe 33 and the heat-conducting box 31 is also dynamically changing.

[0044] Reference Figure 4The control component is a spring steel sheet 36 fixed at one end to the inner bottom wall of the heat-conducting box 31, or a heat-resistant elastic rope fixed at both ends to the inner bottom wall of the heat-conducting box 31. The elastic membrane 35 of this application is divided into an adhesive part and a bonding part. The adhesive part of the elastic membrane 35 is seamlessly bonded to the inner wall of the heat-conducting box 31, while the bonding part of the elastic membrane 35 is bonded to the inner wall of the heat-conducting box 31, and the spring steel sheet 36 presses against the bonding part of the elastic membrane 35. A filter plate 6, which only allows gas to pass through, is fixedly connected to the air inlet end of the one-way air valve 34 and the end of the air pipe 33 near the elastic membrane 35.

[0045] The elastic membrane 35 bulges under the influence of air pressure, but the spring steel sheet 36 presses down on the bonding part of the elastic membrane 35, causing the pressure inside the air pipe 33 to increase until it exceeds the restriction of the elastic membrane 35 by the spring steel sheet 36. At this point, a gap appears between the bonding part of the elastic membrane 35 and the inner wall of the heat-conducting box 31, and nitrogen enters the phase change layer 32 through this gap. At the same time, as the nitrogen is discharged from the air pipe 33, the spring steel sheet 36 presses the elastic membrane 35 again, completing one exhaust process. The filter plate 6 prevents the molten phase change layer 32 inside the heat-conducting box 31 from entering the air pipe 33 through the one-way valve 34 and the elastic membrane 35 end of the air pipe 33, thereby effectively preventing the phase change material from clogging the air pipe 33 and the one-way valve 34.

[0046] Reference Figure 2 and Figure 5 The suction assembly 5 includes a return pipe 51 connected to the feeding hopper 16, a suction pipe 52 connected to the return pipe 51, and a suction pipe 53 connected to the suction pipe 52. The end of the suction pipe 52 near the return pipe 51 is constricted, and the end of the return pipe 51 near the suction pipe 52 is also constricted. The connection between the suction pipe 53 and the suction pipe 52 is located at the constricted end of the suction pipe 53. The suction pipe 53 is connected to the side wall of the temporary storage box 42. An air source is connected to the suction pipe 52. The end of the return pipe 51 near the feeding hopper 16 is connected to a bottom-opening mesh 7 to reduce the speed of the magnetic powder ejected from the return pipe 51.

[0047] When the suction tube 52 draws in air, the airflow moves to the constriction point of the suction tube 52. Due to the reduction in the orifice diameter, the airflow velocity increases and the pressure decreases. That is, the pressure at the end of the suction tube 53 near the suction tube 52 is less than that at the end of the suction tube 53 near the temporary storage box 42. At this time, the magnetic powder in the temporary storage box 42 is drawn in by the suction tube 53. At the same time, the suction tube 52 also draws in the magnetic powder remaining on the surface of the pressed magnetic core. Thus, the magnetic powder on the temporary storage box 42 and the magnetic core is drawn to the return tube 51 and finally fed into the feeding bucket 16 through the return tube 51 to avoid waste of magnetic powder. In addition, after the magnetic core is formed, the suction tube 52 also performs a certain cooling treatment on the magnetic core to reduce the accident of workers being burned.

[0048] Reference Figure 3A plastic screw is fixed to one end of the coil 23 near the middle of the conveyor belt 22. A silicon steel sheet 8 is fitted on the plastic screw. Plastic nuts are threaded to both ends of the plastic screw and the silicon steel sheet 8. The silicon steel sheet 8 effectively enhances the concentration and guidance of the magnetic field generated by the coil 23. Due to factors such as the global transmission of the magnetic field, the magnetic field at the end of the coil 23 away from the silicon steel sheet 8 also changes. This helps to guide the alternating magnetic field to the material trough 121, thereby reducing magnetic field leakage, enhancing the movement efficiency and heating speed of the magnetic powder, and allowing the operator to adjust the height of the silicon steel sheet 8 by adjusting the plastic nuts when the type of magnetic powder or the current of the coil 23 changes.

[0049] Reference Figure 5 Multiple dividing strips 44, each lower than the height of the feeding frame 41, are fixed inside the feeding frame 41. The dividing strips 44 are arc-shaped, and their middle parts are located on the movement path of the material trough 121. When the mold plate 12 rotates, the magnetic powder located inside the feeding frame 41 and above the mold plate 12 is scraped into the material trough 121 by the dividing strips 44. Combined with the slight vibration of the magnetic powder caused by the alternating magnetic field of the coil 23, the magnetic powder in the material trough 121 is compacted and its surface is concave. Then, it is filled by the feeding of the next dividing strip 44, thereby improving the final feeding effect of the material trough 121.

[0050] The implementation principle of the constant temperature pressing molding equipment for magnetic cores in this application embodiment is as follows: the magnetic powder in the feeding barrel 16 falls into the feeding frame 41 through the feeding pipe 17. When the material trough 121 on the mold plate 12 moves to the bottom of the feeding frame 41, the magnetic powder stored in the feeding pipe 17 and the feeding frame 41 falls into the material trough 121. The coil 23 is also conveyed by the conveyor belt 22 to the top of the material trough 121 and moves synchronously with the corresponding material trough 121. At the same time, the brush 25 on the coil 23 is in close contact with the guide rod 24. The two guide rods 24 provide alternating current to the coil 23, thereby causing the coil 23 to generate an alternating magnetic field. The magnetic powder is subjected to the action of the changing magnetic field and vibrates, so that the magnetic powder is tightly attached to each other. At the same time, the magnetic powder is heated due to the eddy current phenomenon.

[0051] The mold plate 12 continues to rotate, and the heated magnetic powder is pressed into a magnetic core by the downward pressure of the upper punch 13. During the magnetic powder pressing process, the temperature of the groove wall of the material tank 121 is transferred to the heat-conducting box 31, and then from the heat-conducting box 31 to the phase change layer 32. When the temperature of the groove wall of the material tank 121 is high, the phase change layer 32 melts and absorbs heat. When the gas pipe 33 is continuously heated, the nitrogen gas in the gas pipe 33 expands and squeezes the elastic membrane 35. When the pressure in the gas pipe 33 is too high, the nitrogen gas pushes open the elastic membrane 35, allowing the elastic membrane 35 to break through the restriction of the spring steel sheet 36, and then allowing the nitrogen gas to enter the heat-conducting box 31. Bubbles are generated inside, and the molten phase change layer 32 is accelerated to flow due to the disturbance of the bubbles, thereby improving the heat exchange effect between the phase change layer 32 and the heat-conducting box 31 on the side close to the material tank 121. When the pressure inside the heat-conducting box 31 is greater than that inside the gas pipe 33, nitrogen enters the gas pipe 33 from the one-way gas valve 34. At the same time, due to the continuous pressing operation and other factors, the temperature of the tank wall of the material tank 121 is always dynamically changing within the specified range. That is, the temperature inside the heat-conducting box 31 and the gas pipe 33 is also always dynamically changing, and the pressure difference between the gas pipe 33 and the heat-conducting box 31 is also dynamically changing.

[0052] After the magnetic core is pressed and formed, the upper punch 13 moves up and resets, and the lower punch 14 moves up and pushes out the magnetic core. When the pushed-out magnetic core moves to the guide plate 15, the magnetic core moves and is unloaded by the guidance of the guide plate 15. Then the lower punch 14 moves down and resets, completing the pressing and forming process of a magnetic core.

[0053] During the process of the magnetic core being pressed and then guided away from the mold plate 12 by the guide plate 15, the suction tube 52 sucks up the magnetic powder remaining on the surface of the magnetic core and reduces the temperature of the magnetic core. At the same time, excess magnetic powder in the temporary storage box 42 is sucked back by the suction tube 52 and eventually flows into the return pipe 51 together with the magnetic powder sucked up by the suction tube 52, so as to reduce the waste of magnetic powder.

[0054] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A dust core constant temperature press forming equipment, comprising a machine body (1), a rotating shaft (11) rotatably arranged on the machine body (1), a mold disc (12) fixedly connected to the rotating shaft (11), an upper punch (13) arranged above the mold disc (12) on the rotating shaft (11), a lower punch (14) arranged below the mold disc (12) on the rotating shaft (11), a guide plate (15) fixedly connected to the machine body (1), a feeding barrel (16) fixedly connected to the machine body (1), and a feeding pipe (17) in communication with the feeding barrel (16), a plurality of material grooves (121) are formed on the mold disc (12) and matched with the upper punch (13) and the lower punch (14), characterized in that: The machine body (1) is fixedly connected with a mounting frame (2) outside the mold disc (12), the mounting frame (2) is fixedly connected with a limiting frame (21) matched with the arc of the mold disc (12), a conveying belt (22) is arranged in the limiting frame (21), a plurality of coils (23) are arranged on the conveying belt (22), the input end and the output end of the coil (23) are fixedly connected to the conveying belt (22), the center of the coil (23) is aligned with the trough (121) of the mold disc (12) and the speed is equal, and a temperature control assembly (3) for controlling the temperature of the trough wall of the trough (121) is arranged in the mold disc (12); ​ Two guide rods (24) are fixedly connected to the mounting frame (2), the input end and the output end of the coil (23) are fixedly connected with an electric brush (25), and when the conveying belt (22) drives the coil (23) to move to a position close to the mold disc (12), the two electric brushes (25) on the coil (23) are respectively abutted against the two guide rods (24), and the mold disc (12) is made of non-magnetic stainless steel; The mounting frame (2) is fixedly connected with a feeding frame (41) away from the guide plate (15) of the feeding pipe (17), the feeding frame (41) is attached to the mold disc (12), one end of the feeding frame (41) away from the feeding pipe (17) is fixedly connected with a temporary storage box (42), the top of the temporary storage box (42) close to one end of the feeding pipe (17) is fixedly connected with an inclined downward shovel plate (43), the shovel plate (43) is also attached to the mold disc (12), and the machine body (1) is provided with a suction assembly (5) for sucking excess magnetic powder in the temporary storage box (42); A plurality of accommodating grooves (122) are arranged around the trough wall of each trough (121) of the mold disc (12), the temperature control assembly (3) comprises a heat conducting box (31) placed in the accommodating groove (122) and a phase change layer (32) filled in the heat conducting box (31), and the phase change layer (32) is a ternary eutectic layer of sodium nitrate, potassium nitrate and sodium nitrite; The temperature control assembly (3) further comprises an air pipe (33) arranged in the peripheral wall of the heat conducting box (31), a one-way air valve (34) arranged at one end of the air pipe (33), an elastic membrane (35) arranged at the other end of the air pipe (33), and a control member for controlling the deflation of the elastic membrane (35), the one-way air valve (34) only allows gas to flow from the heat conducting box (31) into the air pipe (33), the air pipe (33) is filled with nitrogen, and the one-way air valve (34) is located at the top end of the heat conducting box (31).

2. The powder compaction constant temperature press molding apparatus according to claim 1, characterized by: The control member is a spring steel sheet (36) fixed at one end of the bottom wall of the heat-conducting box (31), the elastic film (35) is divided into a bonding part and a fitting part, the bonding part of the elastic film (35) is seamlessly bonded to the inner wall of the heat-conducting box (31), the fitting part of the elastic film (35) is fitted to the inner wall of the heat-conducting box (31), and the spring steel sheet (36) presses the fitting part of the elastic film (35).

3. The powder compaction constant temperature press molding apparatus according to claim 2, characterized by: The air inlet end of the one-way air valve (34) and one end of the air pipe (33) close to the elastic film (35) are fixed with filter plates (6) allowing only gas to pass through.

4. The powder compaction constant temperature press molding apparatus according to claim 1, characterized by: The suction assembly (5) comprises a return pipe (51) in communication with the feeding barrel (16), a suction pipe (52) in communication with the return pipe (51), and a suction pipe (53) in communication with the suction pipe (52), one end of the suction pipe (52) close to the return pipe (51) is in a closed shape, the connection between the suction pipe (52) and the suction pipe (53) is located at the closed end of the suction pipe (53), the suction pipe (53) is in communication with the side wall of the temporary storage box (42), and the suction pipe (52) is externally connected with a gas source.

5. A dust core constant temperature press forming apparatus according to claim 4, characterized in that: One end of the return pipe (51) close to the feeding barrel (16) is connected with an open-bottomed pocket net (7).

6. The powder compaction constant temperature press molding apparatus according to claim 1, characterized by: The coil (23) is provided with a silicon steel sheet (8) at one end close to the middle of the conveying belt (22).

7. The powder compaction constant temperature press molding apparatus according to claim 1, characterized by: A plurality of partition strips (44) with a height lower than that of the feeding frame (41) are fixed in the feeding frame (41), the partition strips (44) are arc-shaped, and the middle part of the partition strips (44) is located on the movement path of the trough (121).

Images