A rare earth powder continuous hot pressing molding strengthening process

Abstract

The present invention relates to the technical field of rare earth powder processing, and discloses a rare earth powder continuous hot pressing molding strengthening process, comprising S1, according to the requirements of the composition of rare earth finished material, preparing corresponding high-purity rare earth metals and transition metals, determining the raw material ratio to meet the performance requirements of the final product, and strictly inspecting the raw materials; S2, melting in a high vacuum environment to prevent metal oxidation. The rare earth powder continuous hot pressing molding strengthening process can effectively solve the problem that in the process of pressing and molding loose rare earth powder to obtain parts with specific geometric shapes in the prior art, due to the irregular shape of rare earth powder particles and uneven particle size distribution, the flow in the mold is not smooth during feeding, there will be too much or too little local accumulation, the internal density of the rare earth powder is inconsistent, and the pressure transmission will be hindered, so that the powder in these parts cannot be fully compacted, thereby affecting the density of the pressed product.

Description

Technical Field

[0001] The invention relates to the technical field of rare earth powder processing, and in particular to a rare earth powder continuous hot pressing molding strengthening process. Background Art

[0002] Rare earth powder is a fine granular substance made from rare earth elements or their compounds. Rare earth elements include scandium, yttrium and lanthanide elements. The compounds or pure metals of these elements are processed through physical processes such as crushing and grinding to form powders with a certain particle size distribution. In the metallurgical industry, rare earths can significantly improve the performance of steel and non-ferrous metals, and improve their strength, toughness, corrosion resistance and wear resistance.

[0003] In the prior art, in the process of pressing loose rare earth powder to obtain parts with specific geometric shapes, due to the irregular shape of rare earth powder particles and uneven particle size distribution, the flow in the mold is not smooth when feeding, and there will be too much or too little accumulation in some areas. The internal density of the rare earth powder is inconsistent, and the pressure transmission will be hindered, so that the powder in these areas cannot be fully compacted, thereby affecting the density of the pressed product. Summary of the invention

[0004] In view of the above-mentioned shortcomings of the prior art, the present invention provides a rare earth powder continuous hot pressing molding strengthening process, which can effectively solve the problem that in the process of pressing and molding loose rare earth powder in the prior art to obtain parts of specific geometric shapes, due to the irregular shape of rare earth powder particles and uneven particle size distribution, the flow in the mold is not smooth during feeding, there will be too much or too little local accumulation, the internal density of the rare earth powder is inconsistent, and the pressure transmission will be hindered, so that the powder in these parts cannot be fully compacted, thereby affecting the density of the pressed product.

[0005] To achieve the above objectives, the present invention is implemented through the following technical solutions:

[0006] The present invention provides a rare earth powder continuous hot pressing molding strengthening process, comprising:

[0007] S1. Prepare the corresponding high-purity rare earth metals and transition metals according to the composition requirements of rare earth finished products, determine the raw material ratio to meet the performance requirements of the final product, and conduct strict quality inspection on the raw materials;

[0008] S2. Melt in a high vacuum environment to prevent metal oxidation, control melting temperature and time, ensure uniform alloy composition, and adopt appropriate cooling methods to obtain an ideal rare earth crystal structure;

[0009] S3, breaking the alloy ingot into pieces of appropriate size to facilitate subsequent powder making, using high-energy ball milling and airflow milling methods to prepare fine and evenly distributed powders, and performing surface treatment on the powders to improve the activity of the powders;

[0010] S4, placing the powder into a pressing device, applying pressure and temperature to shape it, and controlling the pressure, holding time and demolding speed during the pressing process to obtain a dense rare earth product;

[0011] S5. Test the size and density of the product to ensure that it meets the standard requirements;

[0012] S6. Grind and polish the formed rare earth products to remove surface unevenness and demoulding marks, so that the product surface reaches the required precision standard, and clean and package qualified products;

[0013] Wherein, the pressing device in S4 includes a conveying part, the conveying part includes a rotating shaft seat, a transmission rod is fixedly connected to the circumferential outer surface of the rotating shaft seat, four transmission rods are arranged and distributed in a circumferential array with the rotating shaft seat as the center, a base is arranged on the circumferential outer surface of the rotating shaft seat, and an arc-shaped cavity is opened on the upper surface of the base;

[0014] The placing part includes a lower die, a side of the lower die close to the rotating shaft seat is fixedly connected to the output end of the transmission rod, an outer surface of the lower die is fixedly connected to an arc plate that fits the upper surface of the base, a stripping plate is slidably connected to the circumferential inner wall of the lower die, a beating piece that can be used to vibrate the external rare earth powder is provided at the bottom of the lower die, and the stripping plate is provided with an inflatable component through a placing cavity opened inside the stripping plate;

[0015] Among them, the beating part includes an arc rack, the upper surface of the arc rack is fixedly connected to the bottom of the lower mold, the circumferential inner wall of the arc-shaped cavity is rotatably connected to a connecting shaft, the circumferential outer surface of the connecting shaft is sleeved with a gear meshing with the arc rack, and a cam is fixedly connected to the circumferential middle part of the connecting shaft.

[0016] Furthermore, it also includes a pressing part, which includes a frame, and the frame is slidably connected to an upper mold that can be used for pressing external rare earth powder through a hydraulic cylinder arranged on the top of the frame.

[0017] Furthermore, the inflation component includes a ventilation column, the circumferential outer surface of the ventilation column is in contact with the inner wall of the placement cavity, the upper surface of the ventilation column is fixedly connected to a valve core, and the circumferential outer surface of the valve core is fixedly connected to an annular filter.

[0018] Furthermore, a guide rod is fixedly connected to the upper surface of the arc plate, a lifting frame is slidably connected to the outer surface of the guide rod, the lifting frame is fixedly connected to a pressure-maintaining plate for maintaining the pressure of rare earth powder via a connecting frame arranged on the inner wall surface thereof, and a pressure-maintaining assembly is arranged at the bottom of the lifting frame.

[0019] Furthermore, the pressure maintaining assembly includes a connecting rod, the top of which is fixedly connected to the lower surface of the lifting frame, the connecting rod is rotatably connected to a ratchet plate via an inclined groove provided therein, the connecting rod is slidably connected to a reset plate via a sliding groove provided therein, and a ratchet groove engaged with the ratchet plate is provided on one side of the lower mold close to the connecting rod.

[0020] Furthermore, an oil cylinder is provided at the bottom of the base, and a piston rod which can be used to lift the stripping plate is slidably connected inside the oil cylinder, and an L-shaped support frame which fits the lower surface of the connecting frame is fixedly connected to the middle part of a piston rod away from the side of the frame.

[0021] Furthermore, the side of the lifting frame away from the base adopts a magnetic design, the top of the guide rod is fixedly connected to a magnetic plate magnetically connected to the top of the lifting frame, the side of the lifting frame away from the rotating shaft seat is fixedly connected to a buckle, and the upper surface of the base is fixedly connected to a guide plate.

[0022] Compared with the prior art, the technical solution provided by the present invention has the following beneficial effects:

[0023] The present invention is provided with a lower die, a base and a beating member. The lower die moves toward the pressing station so that the arc rack on its lower surface meshes with the gear, driving the cam in the middle of the connecting shaft to rotate. The side with a larger radius of the cam intermittently beats the bottom of the lower die and the stripping plate, so that the bottom of the lower die separates from the base and vibrates slightly up and down, applying a vibration force to the lower die; when the cam hits the bottom of the stripping plate, it moves slightly up and down in the inner wall of the lower die, effectively removing the air between the rare earth powders, making the powder gap more uniform, improving the compactness and density of the powder, and facilitating the uniform density of the subsequently pressed product. The vibration treatment also helps to level the surface of the rare earth powder, avoiding excessive or insufficient local accumulation, and preparing for the subsequent pressing process. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the prior art descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0025] Figure 1This is a flow chart of a rare earth powder hot pressing molding process according to an embodiment of the present invention;

[0026] Figure 2 It is a three-dimensional structural schematic diagram of an embodiment of the present invention;

[0027] Figure 3 This is a schematic diagram of the separation structure of the conveying part, the placing part and the pressing part in an embodiment of the present invention;

[0028] Figure 4 It is a structural schematic diagram of a placement part according to an embodiment of the present invention;

[0029] Figure 5 It is a schematic cross-sectional structure diagram of a pressure-maintaining plate in multiple states according to an embodiment of the present invention;

[0030] Figure 6 For the embodiment of the present invention Figure 5 A schematic diagram of the structure with a partial enlargement at the center;

[0031] Figure 7 For the embodiment of the present invention Figure 5 A schematic diagram of the structure with a partial enlargement at B in the middle;

[0032] Figure 8 It is a schematic cross-sectional structure diagram of a placement portion according to an embodiment of the present invention;

[0033] Fig. 9 This is a schematic structural diagram of an oil cylinder, an L-shaped support frame, a stripping plate and a connecting frame according to an embodiment of the present invention;

[0034] Fig.10 is a cross-sectional view of a base according to an embodiment of the present invention;

[0035] Fig.11 It is a schematic structural diagram of a pressure-maintaining assembly according to an embodiment of the present invention.

[0036] The numbers in the figure represent: 1, conveying part; 11, rotating shaft seat; 12, transmission rod; 13, base; 131, arc cavity; 132, guide plate; 2, placement part; 21, lower mold; 211, arc plate; 212, stripping plate; 213, guide rod; 22, flapper; 221, arc rack; 222, connecting shaft; 223, gear; 224, cam; 23, inflation component; 231, ventilation column; 232, valve core; 2 33. Annular filter; 24. Lifting frame; 241. Connecting frame; 242. Pressure-maintaining plate; 243. Buckle; 25. Pressure-maintaining assembly; 251. Connecting rod; 2511. Inclined groove; 252. Ratchet plate; 253. Slide groove; 254. Reset plate; 255. Ratchet groove; 256. Connecting frame; 26. Magnetic plate; 3. Pressing unit; 31. Frame; 32. Upper die; 33. Cylinder; 331. Piston rod; 332. L-shaped support frame. DETAILED DESCRIPTION

[0037] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0038] The present invention will be further described below in conjunction with the embodiments.

[0039] Example:

[0040] See also Figure 1-Figure 11 The present invention provides a technical solution: a rare earth powder continuous hot pressing molding strengthening process, comprising:

[0041] S1. Prepare the corresponding high-purity rare earth metals and transition metals according to the composition requirements of rare earth finished products, determine the raw material ratio to meet the performance requirements of the final product, and conduct strict quality inspection on the raw materials;

[0042] S2. Melt in a high vacuum environment to prevent metal oxidation, control melting temperature and time, ensure uniform alloy composition, and adopt appropriate cooling methods to obtain an ideal rare earth crystal structure;

[0043] S3, breaking the alloy ingot into pieces of appropriate size to facilitate subsequent powder making, using high-energy ball milling and airflow milling methods to prepare fine and evenly distributed powders, and performing surface treatment on the powders to improve the activity of the powders;

[0044] S4, placing the powder into a pressing device, applying pressure and temperature to shape it, and controlling the pressure, holding time and demolding speed during the pressing process to obtain a dense rare earth product;

[0045] S5. Test the size and density of the product to ensure that it meets the standard requirements;

[0046] S6. Grind and polish the formed rare earth products to remove surface unevenness and demoulding marks, so that the product surface reaches the required precision standard, and clean and package qualified products;

[0047] The pressing device in S4 includes a conveying part 1, which includes a rotating shaft seat 11, a transmission rod 12 is fixedly connected to the circumferential outer surface of the rotating shaft seat 11, four transmission rods 12 are arranged and distributed in a circumferential array with the rotating shaft seat 11 as the center, a base 13 is arranged on the circumferential outer surface of the rotating shaft seat 11, and an arc-shaped cavity 131 is opened on the upper surface of the base 13;

[0048] The placing part 2 includes a lower die 21, a side of the lower die 21 close to the rotating shaft seat 11 is fixedly connected to the output end of the transmission rod 12, an outer surface of the lower die 21 is fixedly connected to an arc plate 211 that fits the upper surface of the base 13, a stripping plate 212 is slidably connected to the circumferential inner wall of the lower die 21, a beating piece 22 that can be used to vibrate the external rare earth powder is provided at the bottom of the lower die 21, and the stripping plate 212 is provided with an inflatable component 23 through a placing cavity opened therein;

[0049] Among them, the beating member 22 includes an arc rack 221, the upper surface of the arc rack 221 is fixedly connected to the bottom of the lower mold 21, the circumferential inner wall of the arc cavity 131 is rotatably connected to a connecting shaft 222, the circumferential outer surface of the connecting shaft 222 is sleeved with a gear 223 meshing with the arc rack 221, and the circumferential middle part of the connecting shaft 222 is fixedly connected with a cam 224, and two gears 223 are provided and are symmetrically distributed with the connecting shaft 222 as the center.

[0050] The machine body further comprises a pressing part 3, which comprises a frame 31. The frame 31 is slidably connected to an upper die 32 for pressing external rare earth powder via a hydraulic cylinder arranged on the top thereof.

[0051] The inflation component 23 includes a ventilation column 231, the circumferential outer surface of the ventilation column 231 is in contact with the inner wall of the placement cavity, and the bottom of the ventilation column 231 extends to the lower surface of the stripping template 212, the upper surface of the ventilation column 231 is fixedly connected to the valve core 232, and the circumferential outer surface of the valve core 232 is fixedly connected to the annular filter screen 233.

[0052] A guide rod 213 is fixedly connected to the upper surface of the arc plate 211, and a lifting frame 24 is slidably connected to the outer surface of the guide rod 213. The lifting frame 24 is fixedly connected to a pressure-maintaining plate 242 for maintaining the pressure of the rare earth powder via a connecting frame 241 arranged on the inner wall surface thereof. A pressure-maintaining assembly 25 is arranged at the bottom of the lifting frame 24. Two groups of guide rods 213 are arranged and are symmetrically distributed with the lifting frame 24 as the center.

[0053] The pressure-maintaining assembly 25 includes a connecting rod 251, and four connecting rods 251 are provided. The top of the connecting rod 251 is fixedly connected to the lower surface of the lifting frame 24. The connecting rod 251 is rotatably connected to the ratchet plate 252 through an inclined groove 2511 opened therein. The connecting rod 251 is slidably connected to the reset plate 254 through a sliding groove 253 opened therein. A ratchet groove 255 engaged with the ratchet plate 252 is opened on one side of the lower mold 21 close to the connecting rod 251.

[0054] An oil cylinder 33 is provided at the bottom of the base 13. There are two oil cylinders 33 distributed in a circular array with the rotating shaft seat 11 as the center. The inside of the oil cylinder 33 is slidably connected with a piston rod 331 that can be used to lift the stripping plate 212. The middle part of a piston rod 331 on the side away from the frame 31 is fixedly connected with an L-shaped support frame 332 that fits the lower surface of the connecting frame 256.

[0055] The side of the lifting frame 24 away from the base 13 adopts a magnetic design, the top of the guide rod 213 is fixedly connected to a magnetic plate 26 that is magnetically connected to the top of the lifting frame 24, the side of the lifting frame 24 away from the rotating shaft seat 11 is fixedly connected to a buckle 243, and the upper surface of the base 13 is fixedly connected to a guide plate 132.

[0056] Four placement parts 2 are provided in the pressing equipment, corresponding to the four workstations of loading, pressing, cooling and holding pressure, and unloading respectively. In actual application, the rotating shaft seat 11 rotates, and the four transmission rods 12 fixedly connected thereto move the four lower molds 21 synchronously inside the base 13. An arc-shaped cavity 131 is opened on the upper surface of the base 13, and the arc-shaped plates 211 on both sides of the lower mold 21 are in contact with the upper surface of the base 13.

[0057] Rare earth powder feeding process:

[0058] In the initial state, the side of the stripper plate 212 inside the lower mold 21 is tightly fitted and slid with the circumferential inner wall of the lower mold 21, and is located at the bottom of the inner wall of the lower mold 21. The magnetic plate 26 is tightly attached to the upper surface of the lifting frame 24. The lifting frame 24 drives the connecting frame 241, the pressure-maintaining plate 242 and the connecting rod 251. Under the action of the guide rod 213, they are at the top of the lower mold 21, and do not affect the normal feeding. During operation, the rare earth powder is transported to the lower mold 21 in the loading station by an external conveying device, and the rare earth powder is located in the space surrounded by the lower mold 21 and the stripper plate 212. After the rare earth powder has been put in, the rotating shaft seat 11 is started and the placement part 2 of the workstation is rotated counterclockwise around the rotating shaft seat 11. During this process, when the arc rack 221 fixedly connected to the bottom of the lower mold 21 passes through the arc cavity 131 on the upper surface of the base 13, the arc rack 221 will engage with the gear 223. When the arc rack 221 passes, it will drive the gear 223 to rotate. At the same time, the connecting shaft 222 fixedly connected to the gear 223 and the cam 224 will rotate together. When the side with a smaller radius of the cam 224 rotates to the highest point, the cam 224 does not contact the stripping plate 212 and the lower mold 21. When the side with a larger radius of the cam 224 rotates to the highest point, the top outer surface of the cam 224 contacts the bottom of the lower mold 21, slightly separating the lower mold 21 as a whole from the base 13. Through the indirect contact between the highest point of the cam 224 and the lower mold 21, a certain vibration force is applied to the lower mold 21, and the air between the rare earth powders inside is discharged upward during the vibration process, making the gaps between the rare earth powders more uniform.

[0059] The lower die 21 continues to rotate following the transmission rod 12. At this time, the side with a larger radius of the cam 224 will contact the lower surface of the stripper plate 212 and lift the stripper plate 212 upward on the inner wall of the lower die 21. When the cam 224 rotates to the side with a smaller radius, the cam 224 does not contact the stripper plate 212. The stripper plate 212 slides down to the bottom under the action of itself and the weight of the rare earth powder. This process is repeated for several cycles. Through the trend of the movement of the lower die 21, the stripper plate 212 moves up and down, making the density of the rare earth powder inside more compact, and the rare earth powder above the lower die 21 is vibrated to be relatively flat. When the lower die 21 continues to move, it will drive the cam 224 to contact the lower surface of the lower die 21 again, transmitting vibration force to the rare earth inside.

[0060] The lower die 21 continues to move with the transmission rod 12 under the action of the rotating shaft seat 11, and the arc rack 221 at the bottom of the lower die 21 is separated from the gear 223. At this time, the rare earth powder density inside the lower die 21 is relatively large, and more air is discharged to the outside. When the lower die 21 continues to move, the buckle 243 on the side of the top lifting frame 24 passes through the guide plate 132. During the movement of this group of placement parts 2, the guide plate 132 gradually becomes lower, driving the buckle 243 to move downward. During the process of the buckle 243 gradually moving downward, the distance between the lifting frame 24 and the magnetic plate 26 increases. After reaching a certain distance, the magnetic plate 26 loses its magnetic connection with the upper surface of the lifting frame 24. The lifting frame 24 drives the connecting frame 241, the connecting rod 251 and the pressure-maintaining plate 242 to move vertically downward under the action of the guide rod 213. The pressure-maintaining plate 242 is concentric with the stripping plate 212, and the moving speed is moderate until the pressure-maintaining plate 242 contacts the upper surface of the rare earth powder. This group of placement parts 2 continues to move. During the movement, the pressure-maintaining plate 242 contacts the rare earth powder in the lower mold 21, so that the surface of the rare earth powder tends to be flat.

[0061] The process of rare earth powder pressing:

[0062] When this set of placement parts 2 continues to rotate clockwise until 90 degrees, the placement part 2 reaches the bottom of the frame 31 and the top of the oil cylinder 33, and the shaft seat 11 stops moving. The shaft seat 11 cooperates with the precision positioning component inside the base 13 to transport the placement part 2 to the exact location. The base 13 of this station is also provided with an inert gas filling device. The inert gas port is inserted from the ventilation column 231 and lifted upward. The ventilation hole opened on the outer surface of the ventilation column 231 moves to the cavity on the outer surface of the valve core 232. In the process, the valve core 232 is no longer tightly fitted with the stripping plate 212, and the valve core 232 moves upward. The annular filter screen 233 fixedly connected to the outer surface of the valve core 232 moves to a position higher than the stripping plate 212. The inflation component 23 adopts a one-way valve design to continuously fill the rare earth powder with inert gas and discharge the air inside the rare earth powder, thereby preventing the rare earth powder from contacting with oxygen. During high-temperature pressing, even if the powder is in an active state, the surrounding inert gas environment can prevent the oxidation reaction from occurring. The airflow generated by inflation can make the rare earth powder produce a "boiling" effect. When the gas flows upward from the bottom, it will push the powder particles upward, reduce the friction between the powder particles, and enhance the fluidity. This helps the powder to be redistributed in the container. After the inflation is completed, it is pulled out from the position of the ventilation column 231, and the ventilation column 231 and the valve core 232 fall back rapidly under the action of gravity and are in a sealed state again.

[0063] At this time, the upper mold 32 is concentric with the lower mold 21, and the oil cylinder 33 is started to drive the piston rod 331 to move upward until its output end contacts the stripping plate 212, giving the stripping plate 212 a supporting force, and then the hydraulic cylinder on the top of the frame 31 is started to drive the upper mold 32 to press downward, and the output end of the upper mold 32 contacts the upper surface of the pressure-maintaining plate 242, and drives the pressure-maintaining plate 242 to move downward together, giving the rare earth powder in the lower mold 21 a higher temperature and greater pressure for hot pressing. In this process, the pressure-maintaining plate 242 is fixedly connected to the connecting frame 241, the lifting frame 24, and the connecting rod 251. When the pressure-maintaining plate 242 descends, it will drive the pressure-maintaining assembly 25 to move downward synchronously. In the initial state, the reset plate 254 inside the connecting rod 251 is at the bottom of the slide groove 253 under the action of its own gravity and the connecting frame 256. The lower surface of the connecting rod 251 does not contact the upper surface of the connecting frame 256, and the inclined groove 2511 is tilted to the right. The right side of the ratchet plate 252 inside the connecting rod 251 is not blocked by the reset plate 254 and is in a state of expansion to the upper right.

[0064] When the pressure-maintaining assembly 25 moves downward, the pawl plate 252 passes through the pawl groove 255 on the outer surface of the lower mold 21. As the depth of descent increases, the pawl plate 252 will continuously engage with the notch at the corresponding position in the pawl groove 255. During this process, the connecting rod 251 and the lower mold 21 move in one direction. Under the action of the pawl plate 252 and the pawl groove 255, the connecting rod 251 can only move downward but not upward. After the frame 31 drives the upper mold 32 to complete the pressing of the powder through the hydraulic cylinder, it is lifted up and restored to the initial state. Since the pawl plate 252 is engaged with the position of the pawl groove 255 corresponding to the lowest point in this stroke, the pressure-maintaining assembly 25 still remains in this position, and the lower surface of the pressure-maintaining plate 242 is tightly fitted with the pressed rare earth powder.

[0065] The process of rare earth powder cooling and pressure holding:

[0066] After the placing part 2 completes the pressing action, the rotating shaft seat 11 continues to start, and the placing part 2 is rotated clockwise by 90 degrees as a whole through the transmission rod 12 and then stops. During this process, the pressure-maintaining plate 242 in the pressure-maintaining assembly 25 is always in close contact with the formed rare earth powder. The rare earth powder pressed and formed inside the lower mold 21, the pressure-maintaining plate 242 and the stripping plate 212 is cooled by an external cooling device.

[0067] The process of feeding rare earth powder:

[0068] After the placement part 2 of this group completes the cooling action, the rotating shaft seat 11 continues to start, and the placement part 2 is rotated clockwise for 90 degrees as a whole through the transmission rod 12 and then stops. The rare earth inside the lower mold 21 completes cooling, and the volume is reduced compared to the initial stage. The height of the rare earth after molding is slightly reduced, and the pressure holding plate 242 moves slightly downward. At this time, the placement part 2 is above the oil cylinder 33. The oil cylinder 33 is started to drive the piston rod 331 to push upward. The outer surface of the circumference of the middle position of the piston rod 331 is fixedly connected to the L-shaped support frame 332. In the initial state, the bottom of the L-shaped support frame 332 is in contact with the upper surface of the oil cylinder 33, and the height of the L-shaped support frame 332 is greater than the length of the piston rod 331 above the L-shaped support frame 332. When the oil cylinder 33 is started, the L-shaped support frame 332 on the outer surface of the piston rod 331 will first contact the lower surface of the connecting frame 256, and drive the connecting frame 256 to move upward, and the reset plate 254 fixedly connected to the connecting frame 256 moves into the inside of the slide groove 253 under the push of the piston rod 331. When the reset plate 254 moves upward in the slide groove 253, the top of the reset plate 254 pushes the right inclined surface of the pawl plate 252, and the pawl plate 252 rotates into the inside of the inclined groove 2511 during the upward process. At this time, the pawl plate 252 is in a retracted state, and its outer surface is no longer in contact with the pawl groove 255, and the pressure-maintaining assembly 25 is no longer fixed to the lower mold 21.

[0069] When the reset plate 254 is completely inside the slide groove 253, the upper surface of the connecting frame 256 fits with the bottom of the connecting rod 251, driving the lifting frame 24, the connecting frame 241 and the pressure-maintaining plate 242 to move upward. At this time, the top of the piston rod 331 moves to engage with the bottom of the stripping plate 212, driving the stripping plate 212 and the formed rare earth to move upward. In this process, the stripping plate 212, the formed rare earth, the connecting rod 251, the lifting frame 24, the connecting frame 241 and the pressure-maintaining plate 242 all push the piston rod 331 upward and move at the same speed.

[0070] With the upward movement, the distance between the lifting frame 24 and the magnetic plate 26 gradually decreases. When the stripping plate 212 is about to be flush with the upper surface of the lower mold 21, the lifting frame 24 is instantly attracted by the magnetic plate 26 under the strong magnetic effect, driving the connecting rod 251, the connecting frame 241 and the pressure-maintaining plate 242 to rise to the highest point. The top of the L-shaped support frame 332 is no longer in contact with the lower surface of the connecting frame 256. The reset plate 254 moves downward inside the slide groove 253 due to gravity. The connecting frame 256 is fixedly connected to the lower surface of the reset plate 254 and no longer fits the bottom end of the connecting rod 251. The ratchet plate 252 in the inclined groove 2511 also loses the support of the reset plate 254 and expands to the outside.

[0071] The oil cylinder 33 continues to drive the piston rod 331 to move upward until the stripping plate 212 is flush with the upper surface of the lower mold 21. At this time, the lifting frame 24 and the pressure holding assembly 25 are both at the top, and the rare earth is pushed to the upper surface of the lower mold 21 through the external push rod. The oil cylinder 33 restores the piston rod 331 to the lower end, and the L-shaped support frame 332 moves downward together. At this time, the lifting frame 24 and the pressure holding assembly 25 are still affected by the magnetic force and are attracted to the magnetic plate 26. The formed rare earth is then taken away by the robotic arm to complete the unloading action.

[0072] After the placing part 2 completes the unloading action, it rotates 90 degrees clockwise and reaches the loading station again, thus completing a rare earth powder pressing process.

[0073] In summary, the process of pressing rare earth powder has the following advantages:

[0074] Advantage 1: There are four workstations for loading, pressing, cooling and pressure holding, and unloading. The four groups of placement parts 2 are driven by the rotating shaft seat 11 to rotate continuously in the four workstations, realizing the automation of the rare earth powder pressing process and significantly improving the production efficiency.

[0075] Advantage 2. After the loading is completed, when the placement part 2 moves toward the pressing station, the arc rack 221 on its lower surface meshes with the gear 223 through its own movement, driving the cam 224 in the middle of the connecting shaft 222 to rotate. The side with a larger radius of the cam 224 intermittently slaps the bottom of the lower mold 21 and the stripper plate 212, so that the bottom of the lower mold 21 is separated from the base 13 and vibrates slightly up and down, applying a vibration force to the lower mold 21. The stripper plate 212 moves slightly up and down in the inner wall of the lower mold 21, effectively removing the air between the rare earth powders, making the powder gaps more uniform, and improving the compactness and density of the powder. The vibration treatment also helps to level the surface of the rare earth powder, laying a good foundation for the subsequent pressing process.

[0076] Advantage three: Before pressing, inert gas is filled into the rare earth powder through the inert gas filling equipment using the filling component 23, which effectively avoids the contact between the rare earth powder and oxygen and prevents the oxidation reaction during high-temperature pressing. The airflow generated by the inert gas filling can make the rare earth powder produce a "boiling" effect. When the gas flows upward from the bottom, it will push the powder particles upward, reduce the friction between the powder particles, and enhance the fluidity. It also promotes the redistribution of the rare earth powder and improves the pressing effect.

[0077] Advantage 4: In the pressing station, the upper mold 32 is pressed downward to closely fit the pressure-maintaining plate 242 and the rare earth powder. The ratchet plate 252 is inside the inclined groove 2511 and is in an inclined state without external force. Due to the clamping relationship between the ratchet plate 252 and the ratchet groove 255, the connecting rod 251 can only continuously move downward on the outer surface of the lower mold 21 and cannot recover. The pressure-maintaining plate 242 is maintained and fixed at the lowest position reached during pressing, which can effectively suppress the rebound deformation of the rare earth product due to elastic recovery and ensure that the shape of the rare earth product meets the design requirements of the mold cavity. If there is no constraint on the rare earth by the pressure-maintaining plate 242, cracks, cavities and other defects may appear inside the product after molding. The pressure-maintaining plate 242 is fixed by the ratchet plate 252 clamping inside the ratchet groove 255, which can slowly release the internal stress of the product and avoid defects caused by stress concentration, thereby improving the quality and performance of the product.

[0078] Advantage 5. In the unloading station, the rare earth product formed on the stripping plate 212 is squeezed upward by the piston rod 331 and the stripping plate 212, and the reset plate 254 is lifted upward inside the slide groove 253 by the L-shaped support frame 332, so that the outward-inclined ratchet plate 252 is in a retracted state. When the lifting is continued, the lifting frame 24 and the pressure-maintaining component 25 can be smoothly restored upward, and the magnetic attraction of the magnetic plate 26 and the lifting frame 24 is used to complete the reset operation of each component, which is convenient for quickly entering the next cycle, shortening the production cycle, giving full play to the utilization efficiency of the equipment, reducing production costs, and improving production economic benefits.

[0079] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements will not cause the essence of the corresponding technical solutions to deviate from the protection scope of the technical solutions of the embodiments of the present invention.

Claims

1. A rare earth powder continuous hot pressing molding strengthening process, characterized in that: include: S1. Prepare the corresponding high-purity rare earth metals and transition metals according to the composition requirements of rare earth finished products, determine the raw material ratio to meet the performance requirements of the final product, and conduct strict quality inspection on the raw materials; S2. Melt in a high vacuum environment to prevent metal oxidation, control melting temperature and time, ensure uniform alloy composition, and adopt appropriate cooling methods to obtain an ideal rare earth crystal structure; S3, breaking the alloy ingot into pieces of appropriate size to facilitate subsequent powder making, using high-energy ball milling and airflow milling methods to prepare fine and evenly distributed powders, and performing surface treatment on the powders to improve the activity of the powders; S4, placing the powder into a pressing device, applying pressure and temperature to shape it, and controlling the pressure, holding time and demolding speed during the pressing process to obtain a dense rare earth product; S5. Test the size and density of the product to ensure that it meets the standard requirements; S6. Grind and polish the formed rare earth products to remove surface unevenness and demoulding marks, so that the product surface reaches the required precision standard, and clean and package qualified products; The pressing device in S4 comprises a conveying part (1), the conveying part (1) comprises a rotating shaft seat (11), a transmission rod (12) is fixedly connected to the circumferential outer surface of the rotating shaft seat (11), four transmission rods (12) are arranged and distributed in a circumferential array with the rotating shaft seat (11) as the center, a base (13) is arranged on the circumferential outer surface of the rotating shaft seat (11), and an arc-shaped cavity (131) is opened on the upper surface of the base (13); A placement portion (2), the placement portion (2) comprising a lower die (21), a side of the lower die (21) close to the rotating shaft seat (11) being fixedly connected to the output end of the transmission rod (12), an outer surface of the lower die (21) being fixedly connected to an arc-shaped plate (211) that fits the upper surface of the base (13), a circumferential inner wall of the lower die (21) being slidably connected to a stripping plate (212), a beating piece (22) that can be used to vibrate rare earth powder being provided at the bottom of the lower die (21), and an inflatable component (23) being provided to the stripping plate (212) via a placement cavity provided therein; The beating member (22) comprises an arc rack (221), the upper surface of the arc rack (221) is fixedly connected to the bottom of the lower mold (21), the circumferential inner wall of the arc-shaped cavity (131) is rotatably connected to a connecting shaft (222), the circumferential outer surface of the connecting shaft (222) is sleeved with a gear (223) meshing with the arc rack (221), and the circumferential middle part of the connecting shaft (222) is fixedly connected to a cam (224); The upper surface of the arc plate (211) is fixedly connected to a guide rod (213), the outer surface of the guide rod (213) is slidably connected to a lifting frame (24), the lifting frame (24) is fixedly connected to a pressure-maintaining plate (242) for maintaining the pressure of rare earth powder through a connecting frame (241) arranged on the inner wall surface thereof, the bottom of the lifting frame (24) is provided with a pressure-maintaining assembly (25), the pressure-maintaining assembly (25) comprises a connecting rod (251), the top of the connecting rod (251) is fixedly connected to the lower surface of the lifting frame (24), and the connecting rod (251) is rotatably connected to a ratchet through an inclined groove (2511) provided inside the connecting rod (251). The connecting rod (251) is slidably connected to a reset plate (254) through a sliding groove (253) provided therein; a pawl groove (255) meshing with the pawl plate (252) is provided on a side of the lower mold (21) close to the connecting rod (251); a side of the lifting frame (24) away from the base (13) adopts a magnetic design; a top end of the guide rod (213) is fixedly connected to a magnetic plate (26) magnetically connected to the top of the lifting frame (24); a side of the lifting frame (24) away from the rotating shaft seat (11) is fixedly connected to a buckle (243); and a guide plate (132) is fixedly connected to the upper surface of the base (13).

2. The rare earth powder continuous hot pressing molding strengthening process according to claim 1, characterized in that: The invention also comprises a pressing part (3), wherein the pressing part (3) comprises a frame (31), and the frame (31) is slidably connected to an upper die (32) for pressing external rare earth powder via a hydraulic cylinder arranged on the top thereof.

3. The rare earth powder continuous hot pressing molding strengthening process according to claim 1, characterized in that: The inflation component (23) comprises a ventilation column (231), the circumferential outer surface of the ventilation column (231) is in contact with the inner wall of the placement cavity, the upper surface of the ventilation column (231) is fixedly connected to a valve core (232), and the circumferential outer surface of the valve core (232) is fixedly connected to an annular filter screen (233).

4. The rare earth powder continuous hot pressing molding strengthening process according to claim 2, characterized in that: An oil cylinder (33) is provided at the bottom of the base (13), and a piston rod (331) which can be used to lift the stripping plate (212) is slidably connected inside the oil cylinder (33), and an L-shaped support frame (332) which fits the lower surface of the connecting frame (256) is fixedly connected to the middle of a piston rod (331) on a side away from the frame (31).

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