A multi-stage screening device and control method for injection molding titanium alloy powder

Abstract

The application relates to a multi-stage screening device and a control method for injection forming of a titanium alloy powder, the screening device comprising a rack, screening devices, a feeding assembly, a first classifier, a second classifier, a third classifier and a dust collector being sequentially arranged on the rack, the feeding assembly being used for conveying the powder into a feeding end of the first classifier, a discharging end of the first classifier being communicated with a feeding end of the second classifier, and a discharging end of the second classifier being communicated with a feeding end of the third classifier and a feeding end of the dust collector, a fan being installed on the rack, an air inlet pipe being communicated between an air outlet end of the fan and the first classifier, a discharging end of the feeding assembly being communicated with the air inlet pipe, a return air pipe being communicated between the dust collector and the air inlet end of the fan, a first screening net and a second screening net being sequentially installed in the screening device from top to bottom, the second screening net having a mesh number of 270 meshes, and the first screening net having a mesh number of 180 meshes. The application has the effect of improving the screening precision of the screening device on MIN powder.

Description

Technical Field

[0001] This application relates to the field of alloy powder sieving technology, and in particular to a multi-stage sieving device and control method for injection-molded titanium alloy powder. Background Technology

[0002] MIM powder (titanium alloy powder for metal injection molding) possesses characteristics such as high strength, low density, good corrosion resistance, and biocompatibility, and has wide applications in aerospace, medical devices, electronic components, and the automotive industry. Due to increasingly stringent requirements for surface finish in the 3C (computer, communication, and consumer electronics) sectors, the control of coarse particles in MIM powder is extremely stringent. The particle size distribution of MIM powder is typically 0-20 μm.

[0003] During sieving, the raw metal powder (0-150μm) that has not been sieved or graded after powdering processes such as atomization is passed through four sieving processes in the air classifier (four classifiers sieve, with sieving precision of 90-150μm, 56-90μm, 20-56μm and 0-20μm respectively). Among them, 90-150μm and 56-90μm are treated as waste, 20-56μm medium powder is used as TC4 powder for 3D printing, and the remaining 0-20μm is MIN powder required for processing.

[0004] However, when classifying metal powders of a specified size, the screening rate cannot reach 100%. Moreover, as the air classifier is used for a long time, the screening accuracy will gradually decrease. Therefore, in the 0-20μm screening stage, a small amount of powder larger than 40μm will be mixed in (the previous screening process did not completely screen the 20-56μm). When using MIN powder to polish the surface of other parts, it will affect the polishing degree of the part surface and cause a few pits on the part surface. Therefore, it is necessary to modify the existing air classifier. Summary of the Invention

[0005] To improve the screening accuracy of MIN powder in screening equipment, this application provides a multi-stage screening device and control method for injection-molded titanium alloy powder.

[0006] This application provides a multi-stage sieving device and control method for injection-molded titanium alloy powder, using the following technical solution: A multi-stage sieving device for injection-molded titanium alloy powder includes a frame. A sieving device, a feeding assembly, a first classifier, a second classifier, a third classifier, and a dust collector are sequentially arranged on the frame. The feeding assembly conveys the powder into the feed end of the first classifier. The discharge end of the first classifier is connected to the feed end of the second classifier, and so on, connecting the second classifier, the third classifier, and the dust collector. A fan is mounted on the frame. An air inlet pipe connects the air outlet of the fan to the first classifier. The discharge end of the feeding assembly is connected to the air inlet pipe. A return air pipe connects the dust collector to the air inlet of the fan. Inside the sieving device, a first sieving screen and a second sieving screen are sequentially installed from top to bottom. The second sieving screen has a mesh size of 270, and the first sieving screen has a mesh size of 180.

[0007] By adopting the above technical solution, during sieving, the powder is sieved to below 90μm through the first sieve screen inside the sieving device, and then sieved to below 56μm through the second sieve screen. The 0-56μm powder enters the air inlet pipe through the feeding assembly. The power of the first classifier, the second classifier, and the third classifier is adjusted so that the accuracy of the first classifier is 41μm, the accuracy of the second classifier is 21μm, and the accuracy of the third classifier is 20μm. The fan is started to transport the powder into the first classifier, and then it is sieved and collected by the first classifier, the second classifier, and the third classifier in sequence. The remaining 0-19μm powder is recycled and processed by the dust collector, achieving the effect of sieving 0-150μm powder. By adding a screening device and modifying the power of the first, second, and third classifiers, a small amount of 21-40μm powder from the previous screening process will be mixed in during the screening of the third screening machine. Compared with the existing technology, this reduces the possibility of powder larger than 40μm entering the MIN powder, reduces the possibility of MIN powder causing a few pits on the surface of the workpiece during the polishing process, and improves the screening accuracy of the screening equipment.

[0008] Optionally, an air cooler is installed on the air inlet duct.

[0009] By adopting the above technical solution, when the first, second, and third classifiers are running, the internal classifying wheels rotate at high speed, causing friction with the internal air. This easily raises the air temperature, causing the powder to heat up. This can lead to phenomena such as powder particle agglomeration, increased crystal size, and aggravated oxidation, reducing the screening efficiency of the screening equipment. By installing an air cooler, the powder and the internal classifying wheels of the three classifiers are cooled during air transport, further reducing the occurrence of the above phenomena and ensuring the powder screening efficiency.

[0010] Optionally, the screening device includes a base, a mounting cylinder, a receiving cylinder, an ultrasonic vibrator, an ultrasonic transducer, a vibrator, and a cover. The base is connected to the frame. The receiving cylinder is positioned above the base and connected to the base by several buffer springs. The vibrator is connected to the bottom of the receiving cylinder. A first discharge port is provided on the surface of the receiving cylinder, which is connected to the feed end of the feeding component. Two mounting cylinders are positioned above the receiving cylinder. A limiting component is provided on the receiving cylinder to restrict the mounting cylinder. A second discharge port is provided on the mounting cylinder. The first screening screen is detachably mounted on the upper mounting cylinder, and the second screening screen is detachably mounted on the lower mounting cylinder. Several ultrasonic transducers are mounted on both the first and second screening screens. The ultrasonic vibrator is mounted on the frame and electrically connected to the ultrasonic vibrator. The cover is detachably connected to the top of the upper mounting cylinder and has a feed port.

[0011] By adopting the above technical solution, during the initial screening of powder, the powder falls onto the first screening screen through the feed inlet. The vibrator and ultrasonic vibrator are started to make the receiving cylinder and the mounting cylinder vibrate. At the same time, the ultrasonic vibrator sends a signal to the ultrasonic transducer, causing the ultrasonic transducer to emit ultrasonic waves to the first screening screen, making the first screening screen vibrate twice to screen powder with a specification of 90-150μm. Similarly, the second screening screen screens powder with a specification of 56-90μm. Finally, the powder with a specification of 0-56 microns enters the feeding assembly and is then transported by the feeding assembly to the air inlet pipe. With the help of the fan, the powder enters the first classifier, thus achieving the effect of screening and transporting the 0-56μm powder to the first classifier.

[0012] Optionally, the limiting assembly includes a limiting ring, a fixing seat, a connecting plate, and a limiting clamp. The limiting ring is mounted on the receiving cylinder. Several fixing seats are connected to the limiting ring, and each fixing seat has a limiting groove. Several connecting plates are mounted on the mounting cylinder and located within the limiting groove. The limiting clamp is U-shaped, and both ends of the limiting clamp are connected to limiting flanges. The limiting clamp is sleeved on the fixing seat and the connecting plate. Both the fixing seat and the connecting plate have clamping grooves, and the limiting flanges are embedded in the clamping grooves. Similarly, this limits the space between the two mounting cylinders.

[0013] By adopting the above technical solution, when restricting the lower mounting cylinder, the lower mounting cylinder is placed inside the restricting ring, and the connecting plate is placed inside the restricting groove. Then, the restricting clamp is sleeved on the fixing seat and the connecting plate. During this process, the restricting flange abuts against the connecting plate and the fixing seat, and the clamp deforms until the restricting flange is embedded in the clamping groove, thereby restricting the movement of the connecting plate and achieving the installation effect of the mounting cylinder.

[0014] Optionally, the limiting clamp is provided with a disassembly assembly, which includes a connecting frame, a rotating column, and a circular plate. One connecting frame is connected to each end of the limiting clamp, and a connecting column is connected to the connecting frame. The rotating column is rotatably connected to the limiting clamp, and the circular plate is connected to the rotating column. A driving arc groove is opened on the circular plate at the position corresponding to the connecting column. The two driving arc grooves are symmetrically arranged about the center of the circular plate. The connecting column is disposed in the driving arc groove and a gap is left between it and the two side walls of the driving arc groove.

[0015] By adopting the above technical solution, during maintenance, rotating the rotating column causes the circular plate to rotate, which in turn drives the two driving arc grooves to rotate, causing the connecting column to move and the connecting frame to deform. This causes the two ends of the limiting clamp to deform until the limiting flange disengages from the clamp groove, at which point the limiting clamp can be removed to remove the lower mounting cylinder. Similarly, the upper mounting cylinder can be removed.

[0016] Optionally, the mounting cylinder is provided with a mounting assembly, which includes a fixing ring, a mounting post, a support spring, an insert block, and a fixing post. The fixing ring is connected to the inner ring wall of the mounting cylinder. Several mounting posts are vertically connected to the fixing ring, and two fixing posts are horizontally connected to the top of the mounting posts. The two fixing posts are arranged opposite each other. The mounting post passes through the first screening screen. The support spring is sleeved on the mounting post and is located between the first screening screen and the fixing ring. The insert block is provided with an abutting inclined surface, an abutting arc groove, and a displacement limiting groove. The abutting arc groove is located at the middle position in the width direction of the insert block, and the displacement limiting groove is located at the top of the insert block. The reference direction is from top to bottom. The length of the insert block gradually increases. When restricted, the abutting arc groove fits against the surface of the mounting post, and the fixing post is located in the displacement limiting groove. The insert block is provided with a stabilizing member to prevent the insert block from detaching from the mounting post.

[0017] By adopting the above technical solution, when installing the first screening screen, the support spring is sleeved on the mounting column, then the first screening screen is sleeved on the mounting column, and finally the moving block is moved to press against the inclined surface and fix the column, causing the first screening screen to descend. The support spring deforms until it contacts the arc groove and fits against the surface of the mounting column. At this time, the fixing column enters the limiting groove, thereby restricting the movement of the first screening screen and realizing the installation of the first screening screen. The second screening screen is installed in the same way.

[0018] Optionally, the stabilizing member is a stabilizing bolt, an L-plate is connected to the top wall of the insert block, the stabilizing member passes through the L-plate and the top of the mounting post, and is threadedly engaged with the mounting post.

[0019] By adopting the above technical solution, after the insert is installed, rotating the stabilizing component causes it to descend and press against the L-plate, further reducing the possibility of the insert detaching from the mounting column due to vibration.

[0020] Optionally, a counterweight is installed at the bottom of the receiving cylinder, and the counterweight is located above the vibrator.

[0021] By adopting the above technical solution, the counterweight is used to increase the weight of the receiving cylinder, thereby lowering the center of gravity of the entire screening device and further improving the stability of the screening device.

[0022] A control method for a multi-stage sieving device for injection-molded titanium alloy powder includes the following steps: S1. Preliminary Sieving: 0-150μm powder is fed into the sieving device through the inlet. The vibrator is started, causing the first and second sieving screens to vibrate. An ultrasonic vibrator sends a vibration signal to the ultrasonic transducer, causing the transducer to emit ultrasonic waves onto the first sieving screen, resulting in double vibration of the first sieving screen. This sieves the 90-150μm powder, which is then discharged from the upper second outlet. Similarly, the second sieving screen vibrates double, sieving the 56-90μm powder, which is then discharged from the lower second outlet. The remaining powder smaller than 56μm exits through the first outlet. S2, Final Sieving: Adjust the power of the first, second, and third classifiers to achieve a sieving accuracy of 41μm for the first classifier, 21μm for the second classifier, and 20μm for the third classifier. The feeding assembly conveys 0-56μm powder into the air inlet pipe. Start the fan, and the air will convey the powder to the first classifier, where it will be sieved sequentially by the first, second, and third classifiers. S3, Residual Powder Processing: The 0-19μm powder sieved by the third classifier enters the dust collector for recycling.

[0023] By adopting the above technical solution and adding a sieving device, the powder entering the first classifier is below 56μm. The power of the first, second, and third classifiers is readjusted. The first classifier sieves powder above 41μm, the second classifier sieves powder above 21μm, and the third classifier sieves powder above 20μm. The remaining 0-19μm powder is recycled in the dust collector. Among them, the 41-56μm and 21-40μm powders are used as TC4 powder for 3D printing, and the 20μm powder is used as MIN powder.

[0024] In summary, this application includes at least one of the following beneficial technical effects: 1. During sieving, the powder is sieved to below 90μm through the first sieve inside the sieving device, and then sieved to below 56μm through the second sieve. The 0-56μm powder enters the air inlet pipe through the feeding assembly. The power of the first classifier, the second classifier, and the third classifier is adjusted so that the accuracy of the first classifier is 41μm, the accuracy of the second classifier is 21μm, and the accuracy of the third classifier is 20μm. The fan is started to transport the powder into the first classifier, and then it is sieved and collected by the first classifier, the second classifier, and the third classifier in sequence. The remaining 0-19μm powder is recycled by the dust collector, achieving the effect of sieving 0-150μm powder. By adding a screening device and modifying the power of the first, second, and third classifiers, a small amount of 21-40μm powder from the previous screening process will be mixed in during the screening of the third screening machine. Compared with the existing technology, this reduces the possibility of powder larger than 40μm entering the MIN powder, reduces the possibility of MIN powder causing a few pits on the surface of the workpiece during the polishing process, and improves the screening accuracy of the screening equipment. 2. When restricting the lower mounting cylinder, place the lower mounting cylinder inside the restricting ring and put the connecting plate into the restricting groove. Then, put the restricting clamping plate on the fixing seat and the connecting plate. During this process, the restricting flange abuts against the connecting plate and the fixing seat, and the clamping plate deforms until the restricting flange is embedded in the clamping groove, thereby restricting the movement of the connecting plate and achieving the installation effect of the mounting cylinder. 3. During maintenance, rotate the rotating column to make the circular plate rotate, which will drive the two drive arc grooves to rotate, causing the connecting column to move and the connecting frame to deform. This will cause the two ends of the limiting clamp to deform until the limiting flange disengages from the clamp groove. Then the limiting clamp can be removed to remove the lower mounting cylinder. Similarly, the upper mounting cylinder can be removed. 4. When installing the first screening screen, place the support spring on the mounting column, then place the first screening screen on the mounting column. Finally, move the insert block to press against the inclined surface and fix the column, causing the first screening screen to descend. The support spring deforms until it contacts the arc groove and fits against the surface of the mounting column. At this time, the fixing column enters the limiting groove, thus restricting the movement of the first screening screen and completing the installation of the first screening screen. The second screening screen is installed in the same way. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the overall structure of the screening equipment in the embodiments of this application.

[0026] Figure 2 This is a schematic diagram of the screening device in the embodiments of this application.

[0027] Figure 3 This is a cross-sectional view used to illustrate the structure of the screening device in the embodiments of this application.

[0028] Figure 4This is an exploded view used in the embodiments of this application to illustrate the structure of the limiting component and the disassembly component.

[0029] Figure 5 yes Figure 3 Enlarged view of point A in the middle.

[0030] Figure 6 This is an exploded view used in the embodiments of this application to illustrate the structure of the installation components.

[0031] Explanation of reference numerals in the attached drawings: 1. Frame; 11. Feeding assembly; 111. Feeding pipe; 112. Feeding hopper; 113. Screw conveyor; 12. First classifier; 13. Second classifier; 14. Third classifier; 15. Dust collector; 16. Fan; 161. Air inlet pipe; 162. Air return pipe; 163. Air cooler; 2. Screening device; 21. Base; 211. Buffer spring; 22. Mounting cylinder; 221. Second discharge port; 222. First screening screen; 223. Second screening screen; 23. Receiving cylinder; 231. Counterweight; 232. First discharge port; 24. Ultrasonic... 25. Ultrasonic transducer; 26. Vibration machine; 27. Cover; 3. Limiting assembly; 31. Limiting ring; 32. Fixing seat; 321. Limiting groove; 33. Connecting plate; 34. Limiting clamp; 341. Limiting flange; 4. Disassembly assembly; 41. Connecting frame; 42. Rotating column; 43. Circular plate; 431. Drive arc groove; 5. Mounting assembly; 51. Fixing ring; 52. Mounting column; 53. Support spring; 54. Insert block; 541. Abutting inclined surface; 542. Abutting arc groove; 543. Movement limiting groove; 544. L-plate; 545. Stabilizer; 55. Fixing column. Detailed Implementation

[0032] The following is in conjunction with the appendix Figures 1-6 This application will be described in further detail.

[0033] This application discloses a multi-stage sieving device and control method for injection-molded titanium alloy powder. (Refer to...) Figure 1 The multi-stage sieving device for injection-molded titanium alloy powder includes a frame 1, on which a sieving device 2, a feeding assembly 11, a first classifier 12, a second classifier 13, a third classifier 14, and a dust collector 15 are arranged sequentially along its length.

[0034] Reference Figure 2 and Figure 3The screening device 2 includes a base 21, a mounting cylinder 22, a receiving cylinder 23, an ultrasonic vibrator 24, an ultrasonic transducer 25, a vibrator 26, and a cover 27. The base 21 is bolted to the frame 1. The receiving cylinder 23 is positioned above the base 21 and is fixedly connected to the base 21 by several buffer springs 211. A counterweight 231 is installed at the bottom of the receiving cylinder 23 to lower the center of gravity of the screening device. The vibrator 26 is installed at the bottom of the receiving cylinder 23 and located inside the base 21, with the counterweight 231 positioned above the vibrator 26. A first discharge port 232 is fixedly connected to the surface of the receiving cylinder 23.

[0035] Reference Figure 3 , Figure 4 and Figure 5 Two mounting cylinders 22 are vertically arranged above the receiving cylinder 23. Each mounting cylinder 22 has a second discharge port 221. A limiting component 3 is provided between the receiving cylinder 23 and the mounting cylinder 22, and between the two mounting cylinders 22. The limiting component 3 includes a limiting ring 31, a fixing seat 32, a connecting plate 33, and a limiting clamping plate 34. One limiting ring 31 is fixedly connected to both the receiving cylinder 23 and the lower mounting cylinder 22. Several fixing seats 32 are fixedly connected to the surfaces of both the receiving cylinder 23 and the lower mounting cylinder 22. In this embodiment, three are used as an example. The fixing seat 32 is provided with a limiting groove 321. Three connecting plates 33 are fixedly connected to both the upper and lower mounting cylinders 22. The connecting plates 33 are placed in the limiting grooves 321.

[0036] Reference Figure 4 and Figure 5 The limiting clamp 34 is U-shaped, and limiting flanges 341 are fixedly connected to the opposite side walls at both ends of the limiting clamp 34. The connecting plate 33 and the fixing seat 32 are both provided with clamping grooves. The limiting clamp 34 is sleeved on the connecting plate 33 and the fixing seat 32, and the limiting flanges 341 are embedded in the clamping grooves.

[0037] Reference Figure 4 and Figure 5 A disassembly assembly 4 is provided on the limiting clamp 34. The disassembly assembly 4 includes a connecting frame 41, a rotating column 42, and a circular plate 43. One connecting frame 41 is fixedly connected to each end of the limiting clamp 34. A connecting column is fixedly connected to the end of the connecting frame 41, and a baffle is fixedly connected to the end of the connecting column. The rotating column 42 is rotatably connected to the limiting clamp 34, and the circular plate 43 is fixedly connected to the rotating column 42. Two driving arc grooves 431 are formed on the circular plate 43, and the two driving arc grooves 431 are symmetrically arranged about the center of the circular plate 43. The connecting column is disposed within the driving arc groove 431, and a gap is left between it and the side walls of the driving arc groove 431.

[0038] When restricting the installation cylinder 22, place the lower installation cylinder 22 inside the restricting ring 31 and place the connecting plate 33 into the restricting groove 321. Then, put the restricting clamp 34 onto the connecting plate 33 and the fixing seat 32. During this process, the restricting flange 341 protrudes from the connecting plate 33 or the fixing seat 32, causing the restricting clamp 34 to deform until the restricting flange 341 enters the clamping groove. The restricting clamp 34 fits against the connecting plate 33 and the fixing groove to restrict the lower installation cylinder 22. Similarly, install the upper installation cylinder 22. During maintenance, rotate the rotating column 42 to make the circular plate 43 rotate. Drive the connecting column to move through the driving arc groove 431, causing the connecting frame 41 to deform. This causes the end of the restricting clamp 34 to deform, causing the restricting flange 341 to disengage from the clamping groove. The restricting clamp 34 can then be removed to take out the installation cylinder 22.

[0039] Reference Figure 2 and Figure 3 The upper mounting cylinder 22 is provided with a first screening screen 222 and a mounting assembly 5. The first screening screen 222 has a mesh size of 180 mesh. Several ultrasonic transducers 25 are mounted on the first screening screen 222. In this embodiment, two are used as an example. The ultrasonic vibrator 24 is mounted on the frame 1, and the ultrasonic transducer 25 is electrically connected to the ultrasonic vibrator 24.

[0040] Reference Figure 3 , Figure 5 and Figure 6 The mounting assembly 5 includes a fixing ring 51, mounting posts 52, a support spring 53, an insert block 54, and fixing posts 55. The fixing ring 51 is fixedly connected inside the upper mounting cylinder 22. Several mounting posts 52 are vertically fixedly connected to the fixing ring 51; in this embodiment, four are used as an example. Two fixing posts 55 are horizontally fixedly connected to the ends of the mounting posts 52, and the two fixing posts 55 are arranged symmetrically about the mounting posts 52. A first screening screen 222 is fitted onto the mounting posts 52, and the support spring 53 is fitted onto the mounting posts 52, located between the first screening screen 222 and the fixing ring 51. The end of the insert block 54 is provided with an abutting inclined surface 541, and the length of the insert block 54 gradually increases from top to bottom as a reference direction. An abutting arc groove 542 is opened at the middle position of the length direction of the insert block 54, and the abutting arc groove 542 fits against the surface of the mounting post 52. A limiting groove 543 is opened at the top of the insert block 54, and the fixing post 55 passes through the limiting groove 543. The mounting assembly 5 also has four sets inside the lower mounting cylinder 22. The lower mounting cylinder 22 is equipped with a second screening screen 223 through the mounting assembly 5. The second screening screen 223 has a mesh size of 270 mesh. Two ultrasonic transducers 25 are also installed on the second screening screen 223.

[0041] Reference Figure 6To reduce the possibility of the insert 54 detaching from the mounting post 52, an L-plate 544 is fixedly connected to the top of the insert 54. A stabilizing member 545 is provided on the L-plate 544. The stabilizing member 545 is a stabilizing bolt. The stabilizing member 545 passes through the L-plate 544 and is threadedly engaged with the top of the mounting post 52.

[0042] When installing the first screening screen 222, the support spring 53 is sleeved on the mounting post 52, and the first screening screen 222 is sleeved on the mounting post 52. Then, the abutting inclined surface 541 of the insert block 54 is pressed against the fixing post 55, the first screening screen 222 descends, the support spring 53 is compressed until the abutting arc groove 542 fits against the mounting post 52, and the fixing post 55 enters the limiting groove 543. Finally, the stabilizing member 545 is rotated until the stabilizing member 545 presses against the L plate 544, thus realizing the installation of the first screening screen 222.

[0043] Reference Figure 2 and Figure 3 The cover 27 is located at the top of the upper mounting cylinder 22 and is connected to the upper mounting cylinder 22 by a buckle. The cover 27 is provided with a feed port.

[0044] Reference Figure 1 The feeding assembly 11 includes a feeding pipe 111 and a feeding hopper 112. The feeding pipe 111 is fixedly connected to the feeding hopper 112 and passes through the frame 1. The feeding pipe 111 is connected to the first discharge port 232. A screw conveyor 113 is installed below the feeding hopper 112. A fan 16 is installed on the frame 1. The air outlet of the fan 16 is connected to the first classifier 12 via an air inlet pipe 161. The discharge port of the screw conveyor 113 is connected to the air inlet pipe 161. An air cooler 163 is installed on the air inlet pipe 161 to reduce the temperature of the powder and the classifying wheels inside the classifier. The discharge port of the first classifier 12 is connected to the feed port of the second classifier 13, and so on. A return air pipe 162 is connected between the dust collector 15 and the air inlet of the classifier.

[0045] Reference Figure 1 The dust collector 15 has a built-in filter bag and is also equipped with a pulse jet generator. The inlet of the return air duct 162 is located inside the filter bag. During collection, powder smaller than 20μm adheres to the surface of the filter bag. The pulse jet generator impacts the filter bag, causing the powder to fall off, thus achieving the effect of collecting powder smaller than 20μm.

[0046] The implementation principle of a multi-stage sieving device for injection-molded titanium alloy powder in this application embodiment is as follows: During sieving, the powder is poured into the sieving device 2 and falls onto the first sieving screen 222. The vibrator 26 and the ultrasonic vibrator 24 are started, and the mounting cylinder 22 and the receiving cylinder 23 vibrate. The first sieving screen 222 is vibrated by the ultrasonic transducer 25, which sieves the powder above 90μm. Similarly, the second sieving screen 223 sieves the powder above 56μm. The remaining powder enters the feed hopper 112 and is transported to the air inlet pipe 161 by the screw conveyor 113. The fan 16 is started, and the powder is transported to the first classifier 12 by the air, which sieves the powder to below 41μm. The second classifier 13 sieves the powder to above 21μm, and the third classifier 14 sieves the powder to 20μm. Finally, the dust collector 15 is used to recycle the powder below 20μm, thus achieving the effect of sieving 20μm powder.

[0047] By adding a screening device 2 and modifying the power of the first classifier 12, the second classifier 13 and the third classifier 14, a small amount of 21-40μm powder from the previous screening process will be mixed in during the screening of the third screening machine. Compared with the existing technology, this reduces the possibility of powder larger than 40μm entering the MIN powder, reduces the possibility of MIN powder causing a few pits on the surface of the workpiece during the polishing process, and improves the screening accuracy of the screening equipment.

[0048] A control method for a multi-stage sieving device for injection-molded titanium alloy powder includes the following steps: S1. Preliminary screening: 0-150μm powder is placed into screening device 2. Vibrator 26 and ultrasonic vibrator 24 are started. Receiving cylinder 23 and mounting cylinder 22 vibrate. Ultrasonic vibrator 24 sends vibration signal to ultrasonic transducer 25. Ultrasonic transducer 25 emits ultrasonic waves to first screening screen 222. Both first screening screen 222 and second screening screen 223 are subjected to double vibration. First screening screen 222 screens powder above 90μm, and second screening screen 223 screens powder above 56μm. Finally, 0-56μm powder is conveyed to feed hopper 112. Through screw conveyor 113 and fan 16, the powder is conveyed into first classifier 12. 56-150μm powder is treated as waste.

[0049] S2. Final Sieving: Adjust the power of the first classifier 12, the second classifier 13, and the third classifier 14 so that the sieving accuracy of the first classifier 12 is 41μm, the sieving accuracy of the second classifier 13 is 21μm, and the sieving accuracy of the third classifier 14 is 20μm. The powder is conveyed by the fan 16 and sieved by the first classifier 12, the second classifier 13, and the third classifier 14 in sequence. Finally, the powder below 20μm is sent to the dust collector 15 for collection. The 41-56μm and 21-40μm powders are used as TC4 powder for 3D printing, and the 20μm powder is used as MIN powder.

[0050] S3. Residual Powder Treatment: Powder smaller than 20μm falls onto the surface of the filter bag inside the dust collector 15. A pulse is released to the filter bag through the pulse generator, causing the filter bag to vibrate and the powder to fall off, thus collecting the powder smaller than 20μm.

[0051] 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 multi-stage sieving device for injection-molded titanium alloy powder, characterized in that: The equipment includes a frame (1), on which a screening device (2), a feeding assembly (11), a first classifier (12), a second classifier (13), a third classifier (14), and a dust collector (15) are sequentially arranged. The feeding assembly (11) is used to convey powder into the feed end of the first classifier (12). The discharge end of the first classifier (12) is connected to the feed end of the second classifier (13), and so on, connecting the second classifier (13), the third classifier (14), and the dust collector (15). A fan (16) is installed on the frame (1), and the air outlet end of the fan (16) is connected to the first classifier. The machine (12) is connected by an air inlet pipe (161), the discharge end of the feeding component (11) is connected to the air inlet pipe (161), the dust collector (15) and the air inlet end of the fan (16) are connected by a return air pipe (162), the screening device (2) is installed with a first screening screen (222) and a second screening screen (223) from top to bottom, the second screening screen (223) has a mesh size of 270 mesh, and the first screening screen (222) has a mesh size of 180 mesh; the screening device (2) includes a base (21), a mounting cylinder (22), a receiving cylinder (23), an ultrasonic vibrator (24), and an ultrasonic transducer. The machine consists of a device (25), a vibrator (26), and a cover (27). A base (21) is connected to a frame (1). A receiving cylinder (23) is positioned above the base (21) and connected to the base (21) by several buffer springs (211). The vibrator (26) is connected to the bottom of the receiving cylinder (23). A first discharge port (232) is provided on the surface of the receiving cylinder (23), which is connected to the feed end of the feeding assembly (11). Two mounting cylinders (22) are positioned above the receiving cylinder (23). A limiting assembly (3) is provided on the receiving cylinder (23) to restrict the mounting cylinder (22). The mounting cylinder (22) is provided with a second discharge port (221). The first screening screen (222) is detachably mounted on the upper mounting cylinder (22), and the second screening screen (223) is detachably mounted on the lower mounting cylinder (22). Several ultrasonic transducers (25) are mounted on both the first screening screen (222) and the second screening screen (223). The ultrasonic vibrator (24) is mounted on the frame (1). The ultrasonic transducer (25) is electrically connected to the ultrasonic vibrator (24). The cover (27) is detachably connected to the top of the upper mounting cylinder (22). The cover (27) is provided with a feed port.The limiting component (3) includes a limiting ring (31), a fixing seat (32), a connecting plate (33), and a limiting clamp (34). The limiting ring (31) is installed on the receiving cylinder (23). Several fixing seats (32) are connected to the limiting ring (31). The fixing seat (32) is provided with a limiting groove (321). Several connecting plates (33) are installed on the mounting cylinder (22) and are located in the limiting groove (321). The limiting clamp (34) is U-shaped. Both ends of the limiting clamp (34) are connected with limiting flanges (341). The limiting clamp (34) is sleeved on the fixing seat (32) and the connecting plate (33). The fixing seat (32) and the connecting plate (33) are both provided with clamping grooves. The limiting flanges (341) are embedded in the clamping grooves. Similarly, the limiting... The control component (3) is positioned between two mounting cylinders (22); a disassembly component (4) is provided on the limiting clamp (34). The disassembly component (4) includes a connecting frame (41), a rotating column (42), and a circular plate (43). One connecting frame (41) is connected to each end of the limiting clamp (34), and a connecting column is connected to the connecting frame (41). The rotating column (42) is rotatably connected to the limiting clamp (34), and the circular plate (43) is connected to the rotating column (42). A drive arc groove (431) is opened on the circular plate (43) at the position corresponding to the connecting column. The two drive arc grooves (431) are symmetrically arranged about the center of the circular plate (43). The connecting column is located in the drive arc groove (431) and a gap is left between it and the two side walls of the drive arc groove (431).

2. The multi-stage sieving device for injection-molded titanium alloy powder according to claim 1, characterized in that: An air cooler (163) is installed on the air inlet pipe (161).

3. The multi-stage sieving device for injection-molded titanium alloy powder according to claim 1, characterized in that: An installation assembly (5) is provided on the installation cylinder (22). The installation assembly (5) includes a fixing ring (51), an installation column (52), a support spring (53), an insert (54), and a fixing column (55). The fixing ring (51) is connected to the inner ring wall of the installation cylinder (22). Several installation columns (52) are vertically connected to the fixing ring (51). Two fixing columns (55) are horizontally connected to the top of the installation column (52). The two fixing columns (55) are arranged opposite to each other. The installation column (52) passes through the first screening screen (222). The support spring (53) is sleeved on the installation column (52) and located on the first screening screen. Between 222) and the fixing ring (51), the insert (54) is provided with an abutting inclined surface (541), an abutting arc groove (542) and a limiting groove (543). The abutting arc groove (542) is located in the middle position of the width direction of the insert (54), and the limiting groove (543) is located at the top of the insert (54). The length of the insert (54) gradually increases from top to bottom. When restricted, the abutting arc groove (542) fits against the surface of the mounting post (52), and the fixing post (55) is located in the limiting groove (543). The insert (54) is provided with a stabilizing member (545) to prevent the insert (54) from detaching from the mounting post (52).

4. The multi-stage sieving device for injection-molded titanium alloy powder according to claim 3, characterized in that: The stabilizing member (545) is a stabilizing bolt. An L-plate (544) is connected to the top wall of the insert (54). The stabilizing member (545) passes through the L-plate (544) and the top of the mounting post (52) and is threadedly engaged with the mounting post (52).

5. The multi-stage sieving device for injection-molded titanium alloy powder according to claim 1, characterized in that: A counterweight (231) is installed at the bottom of the receiving cylinder (23), and the counterweight (231) is located above the vibrator (26).

6. A control method for the screening device according to any one of claims 1-5, characterized in that: Includes the following steps: S1. Preliminary screening: 0-150μm powder is fed into the screening device (2) through the feed port. The vibrator (26) is started to make the first screening screen (222) and the second screening screen (223) vibrate. The ultrasonic vibrator (24) sends a vibration signal to the ultrasonic transducer (25) so that the ultrasonic transducer (25) emits ultrasonic waves to the first screening screen (222), causing the first screening screen (222) to vibrate twice, so that the 90-150μm powder is screened and discharged from the upper second discharge port (221). Similarly, the second screening screen (223) is vibrated twice to make the 56-90μm powder screened and discharged from the lower second discharge port (221). The remaining powder below 56μm enters the feeding assembly (11) from the first discharge port (232). S2, Final sieving: Adjust the power of the first classifier (12), the second classifier (13) and the third classifier (14) so ​​that the sieving accuracy of the first classifier (12) is 41μm, the sieving accuracy of the second classifier (13) is 21μm and the sieving accuracy of the third classifier (14) is 20μm. The feeding assembly (11) conveys the 0-56μm powder into the air inlet pipe (161). Start the fan (16) and the air conveys the powder to the first classifier (12), which is then sieved by the first classifier (12), the second classifier (13) and the third classifier (14) in sequence. S3. Residual powder treatment: The 0-19 micron powder after being screened by the third classifier (14) enters the dust collector (15) for recycling.

Images