A preforming device and forming method for manufacturing a silicon nitride ceramic green body

Abstract

The present invention discloses a preforming method for manufacturing a silicon nitride ceramic green body, which is applied to a preforming device for manufacturing a silicon nitride ceramic green body. The preforming device includes a base bracket, and a first bracket is fixedly connected to the top of the base bracket. By means of the rotation driving assembly of the present invention, two forming die assemblies can be switched, and the double-station switching improves the forming efficiency of the pressing block. The preformed silicon nitride ceramic green body will be ejected from the top of the forming die. When the second cylinder extends, the formed silicon nitride ceramic green body will be pushed away from the top of the rotating plate by the push plate and discharged through the diversion of the ramp plate. Without adding materials and taking out the preformed silicon nitride ceramic green body inside the preforming device, the method of double-station switching can be used for pressing block forming. The addition of materials does not need to be close to the pressing block forming device, and the formed silicon nitride ceramic green body is automatically ejected from the pressing block platform, with relatively high safety, achieving the purpose of improving the forming efficiency of the silicon nitride ceramic green body.

Description

Technical Field

[0001] The present invention belongs to the technical field of manufacturing silicon nitride ceramic green bodies, and particularly relates to a preforming device and a forming method for manufacturing silicon nitride ceramic green bodies. Background Art

[0002] Silicon nitride ceramics are inorganic material ceramics that do not shrink during sintering. Silicon nitride has high strength. In particular, hot-pressed silicon nitride is one of the hardest substances in the world and has properties such as high strength, low density, and high temperature resistance.

[0003] Block pressing is a method for manufacturing silicon nitride ceramic green bodies. Generally, silicon nitride ceramic raw materials are added to a stamping die, and the silicon nitride powder is pressed into blocks and then sintered into silicon nitride ceramics. In the actual operation process, the efficiency of single-station stamping to manufacture silicon nitride ceramic green bodies is relatively low. After stamping and forming, the silicon nitride ceramic green body needs to be manually removed from the stamping table, and the degree of automation is relatively low. Moreover, both feeding and removing the formed silicon nitride ceramic green body need to be operated on the stamping equipment, which is prone to safety hazards. Therefore, we propose a preforming device and a forming method for manufacturing silicon nitride ceramic green bodies, which use a two-station switching method for block pressing. The feeding does not need to be close to the block pressing forming equipment, and the formed silicon nitride ceramic green body is automatically pushed out of the block pressing platform, with relatively high safety and improved forming efficiency of the silicon nitride ceramic green body. Summary of the Invention

[0004] The purpose of the present invention is to provide a preforming device and a forming method for manufacturing silicon nitride ceramic green bodies, which use a two-station switching method for block pressing, the feeding does not need to be close to the block pressing forming equipment, the formed silicon nitride ceramic green body is automatically pushed out of the block pressing platform, with relatively high safety and improved forming efficiency of the silicon nitride ceramic green body, so as to solve the above-mentioned problems in the background art.

[0005] The technical solution for the present invention to solve the above technical problems is as follows: A preforming method for manufacturing a silicon nitride ceramic green body, which is applied to a preforming device for manufacturing a silicon nitride ceramic green body. The preforming device includes a base bracket. A first bracket is fixedly connected to the top of the base bracket. A bearing plate is fixedly connected to the top of the first bracket. A second bracket is fixedly installed on the top of the bearing plate. A fixing plate is fixedly connected to the front side of the second bracket. An activity cylinder is slidably connected to the inner cavity of the fixing plate. A shaft rod is rotatably connected to the bottom of the inner cavity of the activity cylinder. The top of the shaft rod extends to the top of the activity cylinder and is fixedly connected to a rotating plate. A rotating drive assembly is arranged between the activity cylinder and the shaft rod. Forming die assemblies are fixedly installed in an embedded manner on the front side and the rear side of the top of the rotating plate. The forming die assembly includes a forming die fixedly connected to the rotating plate. A die bottom plate that is in close fit with the inner wall of the forming die is slidably connected to the inner cavity of the forming die. A vertical frame is fixedly connected to the tops of the base bracket and the bearing plate. A hydraulic cylinder is fixedly installed on the vertical frame. The output end of the hydraulic cylinder is fixedly installed with an upper pressure head adapted to the forming die assembly. A first cylinder is fixedly installed in an embedded manner on the top of the bearing plate. The output end of the first cylinder is fixedly installed with an ejecting plate. The ejecting plate is adapted to the forming die assembly. A side fixing plate is fixedly installed on the right side of the top of the second bracket. A slope plate is fixedly connected to the left side of the top of the second bracket. A second cylinder is fixedly installed on the top of the side fixing plate. The output end of the second cylinder is fixedly installed with a pushing plate. A jacking assembly is arranged between the activity cylinder and the base bracket;

[0006] A preforming method for manufacturing a silicon nitride ceramic green body. The steps of the preforming method are as follows:

[0007] Step 1: Add silicon nitride ceramic raw materials into the inner cavity of the outer forming die. Then, the motor works to drive the cam plate to rotate clockwise by 90 degrees. The pin on the cam plate causes the inclined push arm to rotate. Due to the fixed bottom plate of the bottom inclined push arm, the cam plate, the motor, and the lifting plate slide upward on the surface of the slide rail due to the sliding sleeve. The top inclined push arm pushes the activity cylinder to move upward in the inner cavity of the fixing plate. The activity cylinder drives the shaft rod, the rotating drive assembly, the rotating plate, and the forming die assembly to move upward until the forming die assembly moves above the pushing plate;

[0008] Step 2: Then, motor 1 drives gear 2 to rotate, drives the threaded rod to rotate through gear 3. The threaded sleeve moves under the guidance of the thread and the guide rod, and then drives the rack to move. The rack drives gear 1 and the shaft rod to rotate 180 degrees. The shaft rod drives the rotating plate to rotate 180 degrees. At this time, the forming die assembly filled with silicon nitride ceramic raw materials enters the inner side and is located directly below the upper pressure head, and the forming die assembly without silicon nitride ceramic raw materials is located on the outer side;

[0009] Step 3: At this time, the motor drives the cam plate to rotate counterclockwise by 90 degrees. Through the cooperation of the shaft pin and the inclined push arm, the lifting plate drives the sliding sleeve to slide downward on the surface of the slide rail, and further makes the movable cylinder, the shaft rod, the rotation drive assembly, the rotating plate and the molding die assembly move downward, so that the rotating plate falls above the second bracket and is located between the side fixed plate and the slope plate. At this time, the hydraulic cylinder works to drive the upper pressure head into the inner cavity of the molding die to press the silicon nitride ceramic raw material into a block, and then the hydraulic cylinder drives the upper pressure head to move upward and reset.

[0010] Step 4: At this time, the first cylinder drives the ejector plate to move upward. When the ejector plate extends into the inner cavity of the molding die, it pushes the die bottom plate upward to eject the molded silicon nitride ceramic raw material out of the inner cavity of the molding die. At this time, the die bottom plate drives the movable rod and the connecting plate to move upward and squeeze the spring. Then the second cylinder drives the push plate to move, and ejects the molded silicon nitride ceramic raw material onto the slope plate and discharges it through the guidance of the slope plate. The first cylinder drives the ejector plate to retract. At this time, the restoring force of the spring makes the connecting plate and the movable rod move downward, and the movable rod drives the die bottom plate to move downward to the bottom of the inner cavity of the molding die for reset. At this time, a quantitative amount of silicon nitride ceramic raw material is loaded into the inner cavity of the outer molding die, and according to the above operations, the briquetting operation is continued.

[0011] Preferably, the rotation drive assembly includes a first gear fixedly connected to the surface of the shaft rod. A threaded rod is rotatably connected to the inner cavity of the movable cylinder. A threaded sleeve is threadedly connected to the surface of the threaded rod. A rack is fixedly connected to one side of the threaded sleeve. The rack meshes with the first gear.

[0012] Preferably, a first motor is fixedly installed in the inner cavity of the movable cylinder. The output shaft of the first motor is fixedly installed with a second gear. A third gear meshing with the second gear is fixedly connected to the surface of the threaded rod.

[0013] Preferably, a guide rod is fixedly connected to the inner cavity of the movable cylinder. The threaded sleeve is slidably connected to the surface of the guide rod.

[0014] Preferably, the jacking assembly includes a bottom plate fixedly connected to the front side of the top of the base bracket. Both sides of the top of the bottom plate are fixedly connected with slide rails. The top of the slide rails is fixedly connected with a fixed plate. The surface of the slide rails is slidably connected with a sliding sleeve. The front sides of the two sliding sleeves are fixedly connected with a lifting plate.

[0015] Preferably, a motor is fixedly installed on the front side of the lifting plate. The output shaft of the motor is fixedly installed with a cam plate. Both ends of the front side of the cam plate are fixedly connected with shaft pins. The surface of the shaft pins is rotatably connected with an inclined push arm. The top of the inclined push arm at the top is rotatably connected with the movable cylinder through a rotating shaft. The bottom of the inclined push arm at the bottom is rotatably connected with the bottom plate through a rotating shaft.

[0016] Preferably, two symmetrical limiting strips are fixedly connected to the surface of the movable cylinder, and limiting grooves for the limiting strips to slide are formed on both sides of the inner cavity of the fixing plate.

[0017] Preferably, a limiting rotating ring is fixedly connected to the bottom of the rotating plate, and the limiting rotating ring is rotatably connected to the top of the surface of the movable cylinder.

[0018] Preferably, movable rods are fixedly connected to the four corners of the bottom of the mold bottom plate, and the bottoms of the movable rods penetrate to the bottom of the forming mold and are slidably connected to the forming mold.

[0019] Preferably, a connecting plate is fixedly connected to the bottom of the movable rod, and a spring is welded between the connecting plate and the forming mold.

[0020] The beneficial effects of the present invention are as follows:

[0021] 1. The present invention can switch between two forming mold assemblies through the rotation drive assembly, and the dual-station switching improves the forming efficiency of the briquette. The preformed silicon nitride ceramic blank will be ejected from the top of the forming mold. When the second cylinder extends, the formed silicon nitride ceramic blank will be pushed away from the top of the rotating plate through the push plate and discharged through the diversion of the ramp plate. It is not necessary to add materials and take out the preformed silicon nitride ceramic blank inside the preforming equipment, and the method of dual-station switching can be used for briquette forming. It is not necessary to approach the briquette forming equipment for feeding, and the formed silicon nitride ceramic blank is automatically ejected from the briquette platform, with relatively high safety, achieving the purpose of improving the forming efficiency of the silicon nitride ceramic blank;

[0022] 2. Through the cooperation of the limiting strip and the limiting groove in the present invention, when the movable cylinder moves up and down, the limiting strip will slide in the inner cavity of the limiting groove, which can guide and support the up and down movement of the movable cylinder, avoiding the situation of lateral deviation of the movable cylinder and ensuring the stability and reliability of the up and down movement of the movable cylinder;

[0023] 3. Through the setting of the limiting rotating ring in the present invention, when the shaft rod drives the rotating plate to rotate, the limiting rotating ring will rotate on the surface of the movable cylinder, limiting and supporting the rotation of the rotating plate and improving the stability of the rotation of the rotating plate;

[0024] 4. Through the setting of the guide rod in the present invention, the threaded sleeve will slide on the surface of the guide rod to guide the movement of the threaded sleeve, avoiding the rotation of the threaded sleeve following the rotation of the threaded rod and improving the stability of the movement of the threaded sleeve. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Through the following detailed description in conjunction with the accompanying drawings, the above and / or other advantages of the present invention will become clearer and easier to understand. These drawings are only schematic and do not limit the present invention, where:

[0026] Figure 1 Schematic three-dimensional view of an embodiment of the present invention;

[0027] Figure 2 Bottom-up three-dimensional view of an embodiment of the present invention;

[0028] Figure 3 Schematic three-dimensional view of a partial structure of an embodiment of the present invention;

[0029] Figure 4 Schematic three-dimensional view of a rotating plate and a lifting assembly of an embodiment of the present invention;

[0030] Figure 5 Schematic exploded three-dimensional view of a fixing plate, a movable cylinder and a rotating plate of an embodiment of the present invention;

[0031] Figure 6 Top view sectional schematic view of a movable cylinder of an embodiment of the present invention;

[0032] Figure 7 Schematic exploded three-dimensional view of a forming die assembly of an embodiment of the present invention.

[0033] In the drawings, the list of components represented by each reference numeral is as follows:

[0034] 1. Base bracket, 2. First bracket, 3. Bearing plate, 4. Second bracket, 5. Fixing plate, 6. Movable cylinder, 7. Shaft rod, 8. Rotating drive assembly, 81. First gear, 82. Threaded rod, 83. Threaded sleeve, 84. Rack, 85. First motor, 86. Second gear, 87. Third gear, 88. Guide rod, 9. Rotating plate, 10. Forming die assembly, 101. Forming die, 102. Die bottom plate, 103. Movable rod, 104. Connecting plate, 105. Spring, 11. Vertical frame, 12. Hydraulic cylinder, 13. Upper punch, 14. First cylinder, 15. Ejector plate, 16. Side fixing plate, 17. Slope plate, 18. Second cylinder, 19. Pushing plate, 20. Lifting assembly, 201. Bottom plate, 202. Slide rail, 203. Sliding sleeve, 204. Lifting plate, 205. Motor, 206. Cam plate, 207. Axle pin, 208. Inclined push arm, 21. Limit strip, 22. Limit groove, 23. Limit rotating ring. Detailed implementation manners

[0035] Hereinafter, embodiments of a preforming device and a forming method for manufacturing a silicon nitride ceramic green body according to the present invention will be described with reference to the drawings.

[0036] The embodiments described herein are specific and particular embodiments of the present invention, which are used to illustrate the concept of the present invention. They are all explanatory and exemplary, and should not be construed as limiting the embodiments of the present invention and the scope of the present invention. Except for the embodiments described herein, those skilled in the art can also adopt other obvious technical solutions based on the content disclosed in the claims and the specification of this application. These technical solutions include those that make any obvious substitutions and modifications to the embodiments described herein.

[0037] The drawings in this specification are schematic diagrams, which assist in illustrating the concept of the present invention and schematically show the shapes of various parts and their mutual relationships. Please note that in order to clearly show the structures of the components in the embodiments of the present invention, the drawings are not drawn in the same proportion. The same reference numerals are used to represent the same parts.

[0038] Embodiment 1

[0039] Figures 1-7A preforming method for manufacturing a silicon nitride ceramic green body according to an embodiment of the present invention is applied to a preforming device for manufacturing a silicon nitride ceramic green body. The preforming device includes a base bracket 1. A bracket 2 is fixedly connected to the top of the base bracket 1. A bearing plate 3 is fixedly connected to the top of the bracket 2. A bracket 4 is fixedly installed on the top of the bearing plate 3. A fixing plate 5 is fixedly connected to the front side of the bracket 4. An activity cylinder 6 is slidably connected to the inner cavity of the fixing plate 5. Two symmetrical limiting strips 21 are fixedly connected to the surface of the activity cylinder 6. Limiting grooves 22 for the limiting strips 21 to slide are formed on both sides of the inner cavity of the fixing plate 5. By the cooperation of the limiting strips 21 and the limiting grooves 22, when the activity cylinder 6 rises and falls, the limiting strips 21 will slide in the inner cavity of the limiting grooves 22, which can guide and support the rising and falling of the activity cylinder 6, avoid the situation of side deviation of the activity cylinder 6, and ensure the stability and reliability of the rising and falling of the activity cylinder 6. A shaft rod 7 is rotatably connected to the bottom of the inner cavity of the activity cylinder 6. The top of the shaft rod 7 extends to the top of the activity cylinder 6 and is fixedly connected to a rotating plate 9. A limiting rotating ring 23 is fixedly connected to the bottom of the rotating plate 9. The limiting rotating ring 23 is rotatably connected to the top of the surface of the activity cylinder 6. Through the setting of the limiting rotating ring 23, when the shaft rod 7 drives the rotating plate 9 to rotate, the limiting rotating ring 23 will rotate on the surface of the activity cylinder 6, limit and support the rotation of the rotating plate 9, and improve the stability of the rotation of the rotating plate 9. A rotation driving assembly 8 is arranged between the activity cylinder 6 and the shaft rod 7. Forming die assemblies 10 are fixedly installed in an embedded manner on the front side and the rear side of the top of the rotating plate 9. The forming die assembly 10 includes a forming die 101 fixedly connected to the rotating plate 9. A die bottom plate 102 that is in close fit with the inner wall of the forming die 101 is slidably connected to the inner cavity of the forming die 101. Four corners of the bottom of the die bottom plate 102 are fixedly connected with activity rods 103. The bottom of the activity rods 103 penetrates to the bottom of the forming die 101 and is slidably connected to the forming die 101. A connecting plate 104 is fixedly connected to the bottom of the activity rods 103. A spring 105 is welded between the connecting plate 104 and the forming die 101. An upright frame 11 is fixedly connected to the top of the base bracket 1 and the bearing plate 3. A hydraulic cylinder 12 is fixedly installed on the upright frame 11. An upper pressing head 13 adapted to the forming die assembly 10 is fixedly installed at the output end of the hydraulic cylinder 12. An air cylinder 14 is fixedly installed in an embedded manner on the top of the bearing plate 3. A top plate 15 is fixedly installed at the output end of the air cylinder 14. The top plate 15 is adapted to the forming die assembly 10. A side fixing plate 16 is fixedly installed on the right side of the top of the bracket 4. A slope plate 17 is fixedly connected to the left side of the top of the bracket 4. An air cylinder 18 is fixedly installed on the top of the side fixing plate 16. A push plate 19 is fixedly installed at the output end of the air cylinder 18. A jacking assembly 20 is arranged between the activity cylinder 6 and the base bracket 1;

[0040] A preforming method for manufacturing a silicon nitride ceramic green body, the steps of the preforming method are as follows:

[0041] Step 1: Add silicon nitride ceramic raw materials into the inner cavity of the outer forming die 101. Then, the motor 205 operates to drive the cam plate 206 to rotate clockwise by 90 degrees. The pin 207 on the cam plate 206 causes the inclined push arm 208 to rotate. Due to the fixed bottom plate 201 of the bottom inclined push arm 208, the cam plate 206, the motor 205, and the lifting plate 204 move upward as the sliding sleeve 203 slides on the surface of the slide rail 202. The top inclined push arm 208 pushes the movable cylinder 6 to move upward in the inner cavity of the fixed plate 5. The movable cylinder 6 drives the shaft rod 7, the rotational drive assembly 8, the rotating plate 9, and the forming die assembly 10 to move upward until the forming die assembly 10 moves above the push plate 19.

[0042] Step 2: Then, the motor 1 85 drives the gear 2 86 to rotate, drives the threaded rod 82 to rotate through the gear 3 87. The threaded sleeve 83 moves under the guidance of the thread and the guide rod 88, thereby driving the rack 84 to move. The rack 84 drives the gear 1 81 and the shaft rod 7 to rotate 180 degrees. The shaft rod 7 drives the rotating plate 9 to rotate 180 degrees. At this time, the forming die assembly 10 filled with silicon nitride ceramic raw materials enters the inner side and is directly below the upper pressure head 13, while the forming die assembly 10 without silicon nitride ceramic raw materials is located on the outer side.

[0043] Step 3: At this time, the motor 205 drives the cam plate 206 to rotate counterclockwise by 90 degrees. Through the cooperation of the pin 207 and the inclined push arm 208, the lifting plate 204 drives the sliding sleeve 203 to slide downward on the surface of the slide rail 202, thereby causing the movable cylinder 6, the shaft rod 7, the rotational drive assembly 8, the rotating plate 9, and the forming die assembly 10 to move downward, causing the rotating plate 9 to fall above the support 2 4 and between the side fixed plate 16 and the ramp plate 17. At this time, the hydraulic cylinder 12 operates to drive the upper pressure head 13 into the inner cavity of the forming die 101 to press the silicon nitride ceramic raw materials into blocks. Then, the hydraulic cylinder 12 drives the upper pressure head 13 to move upward and reset.

[0044] Step 4: At this time, the air cylinder 1 14 drives the ejector plate 15 to move upward. The ejector plate 15 extends into the inner cavity of the forming die 101 and pushes the die bottom plate 102 upward to eject the formed silicon nitride ceramic raw materials from the inner cavity of the forming die 101. At this time, the die bottom plate 102 drives the movable rod 103 and the connecting plate 104 to move upward and squeeze the spring 105. Then, the air cylinder 2 18 drives the push plate 19 to move, pushing the formed silicon nitride ceramic raw materials onto the ramp plate 17 and discharging them through the guidance of the ramp plate 17. The air cylinder 1 14 drives the ejector plate 15 to retract. At this time, the restoring force of the spring 105 causes the connecting plate 104 and the movable rod 103 to move downward, and the movable rod 103 drives the die bottom plate 102 to move downward to the bottom of the inner cavity of the forming die 101 for reset. At this time, a fixed amount of silicon nitride ceramic raw materials is loaded into the inner cavity of the outer forming die 101. According to the above operations, continue the block pressing and forming operations.

[0045] Example Two

[0046] It is basically the same as Example One. Further, the rotation driving assembly 8 includes a first gear 81 fixedly connected to the surface of the shaft rod 7. A threaded rod 82 is rotatably connected to the inner cavity of the movable cylinder 6. A threaded sleeve 83 is threadedly connected to the surface of the threaded rod 82. One side of the threaded sleeve 83 is fixedly connected to a rack 84. The rack 84 meshes with the first gear 81. A first motor 85 is fixedly installed in the inner cavity of the movable cylinder 6. A second gear 86 is fixedly installed on the output shaft of the first motor 85. A third gear 87 meshing with the second gear 86 is fixedly connected to the surface of the threaded rod 82. A guide rod 88 is fixedly connected to the inner cavity of the movable cylinder 6. The threaded sleeve 83 is slidably connected to the surface of the guide rod 88. Through the arrangement of the guide rod 88, the threaded sleeve 83 will slide on the surface of the guide rod 88 to guide the movement of the threaded sleeve 83, avoiding the rotation of the threaded sleeve 83 following the rotation of the threaded rod 82 and improving the stability of the movement of the threaded sleeve 83.

[0047] Example Three

[0048] It is basically the same as Example One. Further, the jacking assembly 20 includes a bottom plate 201 fixedly connected to the front side of the top of the base bracket 1. Both sides of the top of the bottom plate 201 are fixedly connected to slide rails 202. The top of the slide rails 202 is fixedly connected to the fixing plate 5. A sliding sleeve 203 is slidably connected to the surface of the slide rails 202. The front sides of the two sliding sleeves 203 are fixedly connected to a lifting plate 204. A motor 205 is fixedly installed on the front side of the lifting plate 204. A cam plate 206 is fixedly installed on the output shaft of the motor 205. Both ends of the front side of the cam plate 206 are fixedly connected to a pin 207. A slanting push arm 208 is rotatably connected to the surface of the pin 207. The top of the slanting push arm 208 at the top is rotatably connected to the movable cylinder 6 through a rotating shaft. The bottom of the slanting push arm 208 at the bottom is rotatably connected to the bottom plate 201 through a rotating shaft.

[0049] In summary, for the preforming equipment and forming method for manufacturing silicon nitride ceramic blanks, the rotation driving assembly 8 can switch between the two forming die assemblies 10, and the double-station switching improves the forming efficiency of the pressing block. The preformed silicon nitride ceramic blank will be ejected from the top of the forming die 101. When the second cylinder 18 extends, the formed silicon nitride ceramic blank will be pushed away from the top of the rotating plate 9 through the push plate 19 and discharged through the diversion of the slope plate 17. It is not necessary to add materials and take out the preformed silicon nitride ceramic blank inside the preforming equipment. By using the method of double-station switching for pressing block forming, the feeding does not need to be close to the pressing block forming equipment, the formed silicon nitride ceramic blank is automatically ejected from the pressing block platform, with relatively high safety, and the purpose of improving the forming efficiency of the silicon nitride ceramic blank is achieved.

[0050] Each of the technical features disclosed above is not limited to the combinations with other features already disclosed. Those skilled in the art can also make other combinations among the technical features according to the purpose of the invention, subject to achieving the purpose of the present invention.

Claims

1. A preforming method for manufacturing a silicon nitride ceramic green body, which is applied to a preforming device for manufacturing a silicon nitride ceramic green body, and is characterized in that, The preforming device includes a base bracket (1). A first bracket (2) is fixedly connected to the top of the base bracket (1). A bearing plate (3) is fixedly connected to the top of the first bracket (2). A second bracket (4) is fixedly installed on the top of the bearing plate (3). A fixing plate (5) is fixedly connected to the front side of the second bracket (4). An activity cylinder (6) is slidably connected to the inner cavity of the fixing plate (5). A shaft rod (7) is rotatably connected to the bottom of the inner cavity of the activity cylinder (6). The top of the shaft rod (7) extends to the top of the activity cylinder (6) and is fixedly connected to a rotating plate (9). A rotating drive assembly (8) is arranged between the activity cylinder (6) and the shaft rod (7). Forming die assemblies (10) are fixedly installed in an embedded manner on the front side and the rear side of the top of the rotating plate (9). The forming die assembly (10) includes a forming die (101) fixedly connected to the rotating plate (9). A die bottom plate (102) that is in close fit with the inner wall of the forming die (101) is slidably connected to the inner cavity of the forming die (101). An upright frame (11) is fixedly connected to the tops of the base bracket (1) and the bearing plate (3). A hydraulic cylinder (12) is fixedly installed on the upright frame (11). An upper pressure head (13) adapted to the forming die assembly (10) is fixedly installed at the output end of the hydraulic cylinder (12). A first cylinder (14) is fixedly installed in an embedded manner on the top of the bearing plate (3). A jacking plate (15) is fixedly installed at the output end of the first cylinder (14). The jacking plate (15) is adapted to the forming die assembly (10). A side fixing plate (16) is fixedly installed on the right side of the top of the second bracket (4). A slope plate (17) is fixedly connected to the left side of the top of the second bracket (4). A second cylinder (18) is fixedly installed on the top of the side fixing plate (16). A push plate (19) is fixedly installed at the output end of the second cylinder (18). A jacking assembly (20) is arranged between the activity cylinder (6) and the base bracket (1); A preforming method for manufacturing a silicon nitride ceramic blank, and the steps of the preforming method are as follows: Step 1: Add silicon nitride ceramic raw materials into the inner cavity of the outer forming die (101). Then, the motor (205) works to drive the cam plate (206) to rotate clockwise by 90 degrees. The shaft pin (207) on the cam plate (206) causes the inclined push arm (208) to rotate. Due to the fixed bottom plate (201), the bottom inclined push arm (208) causes the cam plate (206), the motor (205), and the lifting plate (204) to move upward due to the sliding sleeve (203) sliding on the surface of the slide rail (202). The top inclined push arm (208) pushes the activity cylinder (6) to move upward in the inner cavity of the fixing plate (5). The activity cylinder (6) drives the shaft rod (7), the rotating drive assembly (8), the rotating plate (9), and the forming die assembly (10) to move upward until the forming die assembly (10) moves above the push plate (19); Step 2: Next, the first motor (85) drives the second gear (86) to rotate, drives the threaded rod (82) to rotate through the third gear (87), and the threaded sleeve (83) moves under the guidance of the thread and the guide rod (88), thereby driving the rack (84) to move. The rack (84) drives the first gear (81) and the shaft rod (7) to rotate 180 degrees, and the shaft rod (7) drives the rotating plate (9) to rotate 180 degrees. At this time, the molding die assembly (10) containing the silicon nitride ceramic raw material enters the inner side and is directly below the upper pressure head (13), and the molding die assembly (10) without the silicon nitride ceramic raw material is located on the outer side; Step 3: At this time, the motor (205) drives the cam plate (206) to rotate counterclockwise by 90 degrees. Through the cooperation of the shaft pin (207) and the inclined push arm (208), the lifting plate (204) drives the sliding sleeve (203) to slide downward on the surface of the slide rail (202), thereby causing the movable cylinder (6), the shaft rod (7), the rotation drive assembly (8), the rotating plate (9), and the molding die assembly (10) to move downward, so that the rotating plate (9) lands above the second bracket (4) and is located between the side fixed plate (16) and the slope plate (17). At this time, the hydraulic cylinder (12) works to drive the upper pressure head (13) into the inner cavity of the molding die (101) to press the silicon nitride ceramic raw material into a block. Then, the hydraulic cylinder (12) drives the upper pressure head (13) to move upward and reset; Step 4: At this time, the first cylinder (14) drives the ejector plate (15) to move upward. The ejector plate (15) extends into the inner cavity of the molding die (101) and pushes the mold bottom plate (102) to move upward to eject the formed silicon nitride ceramic raw material out of the inner cavity of the molding die (101). At this time, the mold bottom plate (102) drives the movable rod (103) and the connecting plate (104) to move upward and compress the spring (105). Then, the second cylinder (18) drives the push plate (19) to move, and ejects the formed silicon nitride ceramic raw material onto the slope plate (17), and discharges it through the guidance of the slope plate (17). The first cylinder (14) drives the ejector plate (15) to retract. At this time, the restoring force of the spring (105) causes the connecting plate (104) and the movable rod (103) to move downward, and the movable rod (103) drives the mold bottom plate (102) to move downward to the bottom of the inner cavity of the molding die (101) for reset. At this time, a fixed amount of silicon nitride ceramic raw material is loaded into the inner cavity of the outer molding die (101). According to the above operations, the block pressing and forming operation is continued.

2. The preforming method for manufacturing a silicon nitride ceramic green body according to claim 1, wherein The rotation drive assembly (8) includes a first gear (81) fixedly connected to the surface of the shaft rod (7). A threaded rod (82) is rotatably connected to the inner cavity of the movable cylinder (6). A threaded sleeve (83) is threadedly connected to the surface of the threaded rod (82). One side of the threaded sleeve (83) is fixedly connected to a rack (84), and the rack (84) meshes with the first gear (81).

3. The preforming method for manufacturing a silicon nitride ceramic green body according to claim 2, characterized in that, A motor one (85) is fixedly installed in the inner cavity of the movable cylinder (6). A gear two (86) is fixedly installed on the output shaft of the motor one (85). A gear three (87) meshing with the gear two (86) is fixedly connected to the surface of the threaded rod (82).

4. A preforming method for manufacturing a silicon nitride ceramic green body according to claim 3, characterized in that, A guide rod (88) is fixedly connected to the inner cavity of the movable cylinder (6). The threaded sleeve (83) is slidably connected to the surface of the guide rod (88).

5. The preforming method for manufacturing a silicon nitride ceramic green body according to claim 4, characterized in that, The jacking assembly (20) includes a bottom plate (201) fixedly connected to the front side of the top of the base bracket (1). Slide rails (202) are fixedly connected to both sides of the top of the bottom plate (201). The top of the slide rails (202) is fixedly connected to the fixed plate (5). A sliding sleeve (203) is slidably connected to the surface of the slide rails (202). A lifting plate (204) is fixedly connected to the front sides of the two sliding sleeves (203).

6. A preforming method for manufacturing a silicon nitride ceramic green body according to claim 5, characterized in that, A motor (205) is fixedly installed on the front side of the lifting plate (204). A cam plate (206) is fixedly installed on the output shaft of the motor (205). Axle pins (207) are fixedly connected to both ends of the front side of the cam plate (206). An inclined push arm (208) is rotatably connected to the surface of the axle pins (207). The top of the inclined push arm (208) at the top is rotatably connected to the movable cylinder (6) through a rotating shaft. The bottom of the inclined push arm (208) at the bottom is rotatably connected to the bottom plate (201) through a rotating shaft.

7. A preforming method for manufacturing a silicon nitride ceramic green body according to claim 6, characterized in that, Two symmetrical limiting strips (21) are fixedly connected to the surface of the movable cylinder (6). Limiting grooves (22) for the limiting strips (21) to slide are formed on both sides of the inner cavity of the fixed plate (5).

8. A preforming method for manufacturing a silicon nitride ceramic green body according to claim 7, characterized in that, A limiting rotating ring (23) is fixedly connected to the bottom of the rotating plate (9). The limiting rotating ring (23) is rotatably connected to the top of the surface of the movable cylinder (6).

9. A preforming method for manufacturing a silicon nitride ceramic green body according to claim 8, characterized in that, Movable rods (103) are fixedly connected to the four corners of the bottom of the mold bottom plate (102). The bottom of the movable rods (103) penetrates to the bottom of the forming mold (101) and is slidably connected to the forming mold (101).

10. The preforming method for manufacturing a silicon nitride ceramic green body according to claim 9, characterized in that, A connecting plate (104) is fixedly connected to the bottom of the movable rod (103). A spring (105) is welded between the connecting plate (104) and the forming mold (101).

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