Isostatic pressing apparatus for molding silicon nitride powder
By incorporating a rotating disk, rack, and gear structure into the silicon nitride powder molding equipment, combined with a stirring shaft and spiral blades, the problem of uneven density caused by powder accumulation was solved, achieving uniform powder distribution and quantitative conveying, thereby improving the density and quality of the molded parts.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- ANYANG JSH NEW MATERIAL CO LTD
- Filing Date
- 2025-06-03
- Publication Date
- 2026-06-23
AI Technical Summary
When silicon nitride powder is loaded into the sheathing tube, the powder tends to accumulate vertically, resulting in uneven filling density and affecting molding quality.
The device employs a rotating disk, rack, and gear structure. The meshing of the rack and gears drives the sheath tube to oscillate back and forth. Combined with the design of the stirring shaft, stirring rod, and spiral blades, it achieves uniform distribution and quantitative delivery of powder.
This improved the pre-compaction of the powder, reduced the porosity of the molded parts, ensured uniform pressure on the powder during the subsequent isostatic pressing process, and improved the density and quality of the molded parts.
Smart Images
Figure CN224388891U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of silicon nitride powder technology, and in particular to an isostatic pressing device for silicon nitride powder molding. Background Technology
[0002] The molding process is a key step in the preparation of silicon nitride materials. Currently, isostatic pressing (especially cold isostatic pressing) has become one of the mainstream methods because it can achieve uniform pressure on the blank and improve density and mechanical properties. This process involves loading powder into an elastic mold (such as a rubber or plastic sleeve), placing it in a high-pressure container, and using a liquid medium to uniformly transmit pressure, so that the powder is compacted and formed.
[0003] However, when loading silicon nitride powder into the sheathing tube, the powder is usually directly fed into the sheathing tube through the feed pipe. The powder enters the sheathing tube vertically, which can easily cause the powder to accumulate inside the tube, resulting in large gaps between the powder particles and inconsistent powder filling density in different areas of the sheathing tube. Therefore, we need to consider how to solve this problem. Utility Model Content
[0004] The purpose of this invention is to address the shortcomings of existing technologies by proposing an isostatic pressing device for silicon nitride powder molding. This device is equipped with a rotating disk, rack and gears, etc. Under the meshing transmission of the rack and gears, the cladding tube can reciprocate, causing the powder inside to rearrange under the action of gravity and inertia, thus providing a uniform material base for subsequent isostatic pressing.
[0005] To achieve the above objectives, the present invention adopts the following technical solution:
[0006] An isostatic pressing device for silicon nitride powder molding includes a conveyor. A sheath is placed at the upper end of the conveyor, and a pipe cover is installed at the upper end of the sheath. An mounting plate is fixedly connected to one side wall of the conveyor. Two hydraulic cylinders are installed at the lower end of the mounting plate. The output ends of the two hydraulic cylinders are fixedly connected to connecting plates. A material hopper is fixedly connected to the opposite sides of the two connecting plates. A stirring shaft is rotatably connected to the inner top of the material hopper. Multiple stirring rods are fixedly connected to the outer wall of the stirring shaft. A spiral blade is fixedly connected to the lower end of the stirring shaft. A through hole is opened at the upper end of the pipe cover. A fixing plate is fixedly connected to the other side wall of the conveyor, and a reciprocating swing mechanism is provided on the fixing plate.
[0007] Preferably, a first motor is installed at the upper end of the material barrel, and the end of the output shaft of the first motor extends into the interior of the material barrel and is fixedly connected to the upper end of the stirring shaft.
[0008] Preferably, a telescopic rod is installed on the inner side wall of the pipe cover, and a stop block is fixedly connected to the telescopic end of the telescopic rod. The stop block cooperates with the through hole. A spring is sleeved on the outer wall of the telescopic rod, and the two ends of the spring are elastically connected to the inner wall of the pipe cover and the side wall of the stop block, respectively.
[0009] Preferably, the reciprocating swing mechanism includes a second motor installed at the lower end of the fixed plate, the output shaft of the second motor passing through the fixed plate and fixedly connected to a rotating disk, and a transmission rod fixedly connected to the upper end of the rotating disk.
[0010] Preferably, two fixing blocks are fixedly connected to the upper end of the fixing plate, a guide rod is fixedly connected between the two fixing blocks, a rack slides through the guide rod, a transmission plate is fixedly connected to one side wall of the rack, a transmission groove that cooperates with the transmission rod is opened on the transmission plate, a rotating shaft is rotatably connected to the upper end of the fixing plate, a gear is fixedly connected to the outer wall of the rotating shaft, and the gear meshes with the rack.
[0011] Preferably, a rotating plate is fixedly connected to the upper end of the rotating shaft, two electric push rods are installed on one side wall of the rotating plate, a rectangular plate is fixedly connected to the other end of each of the two electric push rods, and clamping plates are fixedly connected to the opposite sides of the two rectangular plates, with the two clamping plates cooperating with the sheathing tube.
[0012] Compared with the prior art, the advantages of this utility model are as follows:
[0013] 1. The structure includes a stirring shaft, stirring rods, and spiral blades. The stirring shaft drives multiple stirring rods to rotate, which breaks up the agglomerated powder particles in the material bucket and avoids molding defects caused by local density differences. The axial thrust generated by the spiral blades can stably transport the powder from the material bucket to the casing tube, realizing quantitative feeding of powder.
[0014] 2. The structure includes a rotating disk, rack and pinion, and gears. The meshing of the rack and pinion drives the sleeving tube to swing, which makes the powder particles more compact and improves the pre-compaction. This provides a more uniform pressure base for the subsequent isostatic pressing process and avoids uneven density or hole defects in the molded parts caused by loose accumulation. Attached Figure Description
[0015] Figure 1 This is a schematic diagram of the isostatic pressing equipment for silicon nitride powder molding proposed in this utility model.
[0016] Figure 2 for Figure 1 A schematic diagram of the front cross-section;
[0017] Figure 3 for Figure 2 Enlarged view of point A;
[0018] Figure 4 for Figure 1 A schematic diagram of the right-side cross-section;
[0019] Figure 5 for Figure 4 Enlarged view of point B;
[0020] Figure 6 for Figure 1 A schematic diagram of the upper cross-section.
[0021] In the diagram: 1 Conveyor, 2 Sheath, 3 Pipe Cover, 4 Mounting Plate, 5 Hydraulic Cylinder, 6 Connecting Plate, 7 Material Bucket, 8 Agitator Shaft, 9 Agitator Rod, 10 Spiral Blade, 11 First Motor, 12 Telescopic Rod, 13 Stop Block, 14 Spring, 15 Fixing Plate, 16 Second Motor, 17 Rotating Disc, 18 Transmission Rod, 19 Fixing Block, 20 Guide Rod, 21 Rack, 22 Transmission Plate, 23 Transmission Groove, 24 Rotating Shaft, 25 Gear, 26 Rotating Plate, 27 Electric Push Rod, 28 Rectangular Plate, 29 Clamping Plate. Detailed Implementation
[0022] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments.
[0023] Reference Figures 1-6 An isostatic pressing device for silicon nitride powder molding includes a conveyor 1, which is existing technology and will not be described in detail here. The end of the conveyor 1 is directly connected to the feed port of the isostatic pressing chamber via a conveyor belt. A sheathing tube 2 is placed on the upper end of the conveyor 1, and a tube cover 3 is installed on the upper end of the sheathing tube 2. An mounting plate 4 is fixedly connected to one side wall of the conveyor 1. Two hydraulic cylinders 5 are installed on the lower end of the mounting plate 4. A connecting plate 6 is fixedly connected to the output end of each of the two hydraulic cylinders 5. A material bucket 7 is fixedly connected to the opposite side of the two connecting plates 6. A feed port is fixedly connected to the upper end of the material bucket 7. A stirring shaft 8 is rotatably connected to the inner top of the material bucket 7. Multiple stirring rods 9 are fixedly connected to the outer wall of the stirring shaft 8. By using the stirring shaft 8 and multiple stirring rods 9, the silicon nitride powder can be stirred to ensure that the powder particles are evenly dispersed and to avoid uneven molding density caused by agglomeration. A spiral blade 10 is fixedly connected to the lower end of the stirring shaft 8. A discharge port is fixedly connected to the lower end of the material bucket 7, and the spiral blade 10 is located inside the discharge port.
[0024] The material barrel 7 is equipped with a first motor 11 at its upper end. The first motor 11 is a servo motor. The output shaft of the first motor 11 extends into the material barrel 7 and is fixedly connected to the upper end of the stirring shaft 8. The spiral blade 10 is matched with the discharge port. The continuous quantitative conveying of powder can be achieved by controlling the speed of the first motor 11. The upper end of the pipe cover 3 is provided with a through hole, which is matched with the discharge port. The inner side wall of the pipe cover 3 is equipped with a telescopic rod 12. The telescopic end of the telescopic rod 12 is fixedly connected with a stop block 13. The stop block 13 is matched with the through hole to block the through hole. The outer wall of the telescopic rod 12 is fitted with a spring 14. The two ends of the spring 14 are elastically connected to the inner wall of the pipe cover 3 and the side wall of the stop block 13, respectively. When the through hole of the pipe cover 3 is aligned with the discharge port, the stop block 13 opens the through hole under the action of the telescopic rod 12, and the powder falls into the casing tube 2. After the feeding is completed, the spring 14 pushes the stop block 13 to reset, thereby sealing the through hole and preventing powder leakage or external impurities from entering during the isostatic pressing process.
[0025] Among them, a fixed plate 15 is fixedly connected to the other side wall of the conveyor 1. A reciprocating swing mechanism is provided on the fixed plate 15. The reciprocating swing mechanism includes a second motor 16 installed at the lower end of the fixed plate 15. The second motor 16 is a servo motor. The output shaft of the second motor 16 passes through the fixed plate 15 and is fixedly connected to a rotating disk 17. A transmission rod 18 is fixedly connected to the upper end of the rotating disk 17. Two fixed blocks 19 are fixedly connected to the upper end of the fixed plate 15. A guide rod 20 is fixedly connected between the two fixed blocks 19. A rack 21 slides through the guide rod 20. The transmission rod 18 is located at the edge of the rotating disk 17 and can drive the rack 21 to move back and forth. A transmission plate 22 is fixedly connected to one side wall of the rack 21. A transmission groove 23 that cooperates with the transmission rod 18 is opened on the transmission plate 22. The transmission groove 23 is an arc groove with a radius of curvature that is consistent with the radius of rotation of the transmission rod 18. The transmission rod 18 can slide in the transmission groove 23.
[0026] The upper end of the fixed plate 15 is rotatably connected to a rotating shaft 24. A gear 25 is fixedly connected to the outer wall of the rotating shaft 24, and the gear 25 meshes with a rack 21. A rotating plate 26 is fixedly connected to the upper end of the rotating shaft 24. The second motor 16 drives the rotating disk 17 to rotate. Through the cooperation of the transmission rod 18 and the rack 21, the circular motion is converted into the linear reciprocating motion of the rack 21. Then, through the meshing transmission of the gear 25 and the rack 21, the oscillation of the rotating plate 26 can be realized. Two electric push rods 27 are installed on one side wall of the rotating plate 26. The other end of 7 is fixedly connected to a rectangular plate 28. The opposite sides of the two rectangular plates 28 are fixedly connected to a clamping plate 29. The two clamping plates 29 are arc-shaped and cooperate with the sleeve tube 2. The two electric push rods 27 drive the rectangular plates 28 and the clamping plates 29 to clamp and fix the sleeve tube 2. In this way, the reciprocating swing of the rotating plate 26 can be transmitted to the sleeve tube 2 through the clamping plate 29, so that the powder in the tube undergoes a swinging process before isostatic pressing, reducing the air gap between the powders, increasing the density after isostatic pressing, and reducing the porosity of the molded part.
[0027] In this utility model, during use, the equipment transports the sheath tube 2 to the designated work station via the conveyor 1. When the sheath tube 2 reaches the designated position of the conveyor 1, the hydraulic cylinder 5 is activated to push the material bucket 7 down, so that the discharge port at the lower end of the material bucket 7 is aligned with the through hole of the tube cover 3. At this time, the stop block 13 will move away from the through hole, and the discharge port will be connected to the through hole to form a powder conveying channel. Then, the first motor 11 is activated to drive the stirring shaft 8 to rotate, which drives the stirring rod 9 to stir the silicon nitride powder in the material bucket 7, break up the lumps and mix them evenly. At the same time, the spiral blade 10 at the lower end of the stirring shaft 8 is located in the discharge port. The axial thrust generated by its rotation pushes the powder from the discharge port into the sheath tube 2. In this way, by controlling the speed of the first motor 11, the powder conveying amount can be adjusted to achieve quantitative feeding. After the feeding is completed, the elastic action of the spring 14 will push the stop block 13 to reset, tightly sealing the through hole to prevent powder leakage or external impurities from entering during the isostatic pressing process.
[0028] Then, the two electric push rods 27 are activated, causing the two clamping plates 29 to clamp the sleeve tube 2. The arc-shaped clamping plates 29 fit against the outer wall of the tube, providing a stable clamping force. Next, the second motor 16 can be activated to drive the rotating disk 17 to rotate. The transmission rod 18 fixed on the edge of the rotating disk 17 then makes a circular motion. The transmission rod 18 is inserted into the arc-shaped transmission groove 23 of the transmission plate 22, driving the transmission plate 22 and the rack 21 to move back and forth linearly along the guide rod 20. The rack 21 meshes with the gear 25, converting the linear motion into the reciprocating oscillation of the gear 25, which in turn drives the rotating plate 26 to oscillate through the rotating shaft 24. The oscillation of the rotating plate 26 is transmitted to the sleeve tube 2 through the clamping plate 29, causing the powder inside the tube to rearrange under the action of gravity and oscillation inertia, filling the pores and improving the pre-compaction.
[0029] After compaction, conveyor 1 transports the sheath 2 to the inlet of the isostatic pressure chamber. After the sheath 2 enters the chamber with conveyor 1, the equipment fills the chamber with a high-pressure medium (such as oil or water). Through uniform pressure in all directions, the silicon nitride powder is finally formed into a high-density preform. After forming, the sheath 2 is sent out by conveyor 1, the tube cover 3 is opened to take out the blank, and it enters the subsequent process.
[0030] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model, based on the technical solution and the inventive concept of the present utility model, should be included within the protection scope of the present utility model.
Claims
1. An isostatic pressing device for silicon nitride powder molding, comprising a conveyor (1), characterized in that, The upper end of the conveyor (1) is provided with a sheath (2), and the upper end of the sheath (2) is provided with a pipe cover (3). A mounting plate (4) is fixedly connected to one side wall of the conveyor (1). Two hydraulic cylinders (5) are installed at the lower end of the mounting plate (4). A connecting plate (6) is fixedly connected to the output end of each of the two hydraulic cylinders (5). A material bucket (7) is fixedly connected to the opposite side of the two connecting plates (6). A stirring shaft (8) is rotatably connected to the inner top of the material bucket (7). Multiple stirring rods (9) are fixedly connected to the outer wall of the stirring shaft (8). A spiral blade (10) is fixedly connected to the lower end of the stirring shaft (8). A through hole is opened at the upper end of the pipe cover (3). A fixing plate (15) is fixedly connected to the other side wall of the conveyor (1). The fixed plate (15) is provided with a reciprocating swing mechanism.
2. The isostatic pressing equipment for silicon nitride powder molding according to claim 1, characterized in that, The upper end of the material barrel (7) is equipped with a first motor (11), the output shaft of the first motor (11) extends into the material barrel (7) and is fixedly connected to the upper end of the stirring shaft (8).
3. The isostatic pressing equipment for silicon nitride powder molding according to claim 1, characterized in that, The inner wall of the pipe cover (3) is equipped with a telescopic rod (12), and the telescopic end of the telescopic rod (12) is fixedly connected to a stop block (13). The stop block (13) cooperates with the through hole. The outer wall of the telescopic rod (12) is fitted with a spring (14), and the two ends of the spring (14) are elastically connected to the inner wall of the pipe cover (3) and the side wall of the stop block (13), respectively.
4. The isostatic pressing equipment for silicon nitride powder molding according to claim 1, characterized in that, The reciprocating swing mechanism includes a second motor (16) installed at the lower end of the fixed plate (15). The output shaft of the second motor (16) passes through the fixed plate (15) and is fixedly connected to a rotating disk (17). A transmission rod (18) is fixedly connected to the upper end of the rotating disk (17).
5. The isostatic pressing equipment for silicon nitride powder molding according to claim 4, characterized in that, The upper end of the fixed plate (15) is fixedly connected to two fixed blocks (19), and a guide rod (20) is fixedly connected between the two fixed blocks (19). A rack (21) slides through the guide rod (20). A transmission plate (22) is fixedly connected to one side wall of the rack (21). A transmission groove (23) that cooperates with the transmission rod (18) is opened on the transmission plate (22). A rotating shaft (24) is rotatably connected to the upper end of the fixed plate (15). A gear (25) is fixedly connected to the outer wall of the rotating shaft (24). The gear (25) meshes with the rack (21).
6. The isostatic pressing equipment for silicon nitride powder molding according to claim 5, characterized in that, The upper end of the rotating shaft (24) is fixedly connected to a rotating plate (26). Two electric push rods (27) are installed on one side wall of the rotating plate (26). The other end of each of the two electric push rods (27) is fixedly connected to a rectangular plate (28). The opposite sides of the two rectangular plates (28) are fixedly connected to clamps (29). The two clamps (29) cooperate with the sheath (2).