Compartment type powder cleaning system with fixed formed part

Abstract

A piston driving device drives a forming piston to do lifting motion in a forming cylinder, a forming cylinder lifting driving device drives the forming cylinder to do lifting motion, and the upper end of the forming cylinder can be inserted into an opening of a bottom plate of a forming chamber in a sealed mode and is connected with a working plane on the upper side of the bottom plate of the forming chamber in an aligned mode. The powder cleaning cylinder driving device drives the powder cleaning outer cylinder to do lifting motion, the upper end face of the powder cleaning outer cylinder can make sealing contact with the lower side face of a bottom plate of the forming chamber, the lower portion of the forming cylinder and the lower portion of the powder cleaning outer cylinder can be aligned and connected with the upper end face of a forming piston after 3D printing is completed, and a powder containing space with the upper end face of the forming cylinder and the upper end face of the forming piston as the bottom face can be formed in the powder cleaning outer cylinder. According to the 3D printing equipment, the centering precision of the forming cylinder can be guaranteed, and intelligent and automatic powder cleaning and piece taking of the 3D printing equipment are achieved.

Description

Technical Field

[0001] The present invention relates to a laser vacuum SLM printer, and particularly to a box-type powder cleaning system with a stationary formed part. Background Art

[0002] With the popularization of metal 3D printing forming technology, people's requirements for the automation of metal 3D printing are getting higher and higher. The traditional workpiece taking method is as follows: first, the entire forming cylinder is moved out of the machine, then the workpiece is pushed upward out of the forming cylinder, and the powder on the workpiece is removed manually to expose the workpiece, and then the workpiece is taken. This workpiece taking method is very cumbersome, time-consuming, and has high requirements for the movement system of the forming cylinder. For C-class (disk-shaped) metal 3D printed parts, the height is generally relatively low. If the traditional workpiece taking method is adopted, it will lead to extremely low production efficiency of the product and high production costs. Summary of the Invention

[0003] In order to make up for the above deficiencies, the present invention provides a box-type powder cleaning system with a stationary formed part. The box-type powder cleaning system with a stationary formed part has a simple structure, can simplify the movement system of the forming cylinder of the 3D printing device, realize rapid workpiece taking, and is beneficial to realizing the automated production of 3D printing.

[0004] The technical solution adopted by the present invention to solve its technical problems is: a box-type powder cleaning system with a stationary formed part, including a forming chamber, a forming cylinder, a forming piston, and a piston driving device. The forming piston is circumferentially stopped and axially slidable up and down in the forming cylinder, and the piston driving device drives the forming piston to move up and down. It also includes a forming cylinder lifting driving device, a powder cleaning outer cylinder, a powder cleaning cylinder driving device, and a vacuum cleaner. The forming cylinder is installed below the forming chamber and can move up and down. The forming cylinder lifting driving device can drive the forming cylinder to move up and down. After the forming cylinder rises, its upper end can be inserted into the opening of the bottom plate of the forming chamber in a sealed manner and aligned with the working plane on the upper side of the bottom plate of the forming chamber, or can be tightly abutted against the lower surface of the bottom plate of the forming chamber in a sealed manner and the inner side surface of the forming cylinder is aligned with the inner side wall of the opening of the bottom plate of the forming chamber. After the forming cylinder descends, its upper end plane can be aligned with the upper end face of the forming piston when 3D printing is completed. The powder cleaning outer cylinder is installed directly below the forming chamber and can move up and down. The upper end face of the powder cleaning outer cylinder can be in sealed contact with the lower side surface of the bottom plate of the forming chamber, and the inner side surface of the powder cleaning outer cylinder is in sealed contact with the outer side surface of the forming cylinder. The powder cleaning cylinder driving device can drive the powder cleaning outer cylinder to move up and down so that its upper end face is in sealed contact with the lower side surface of the bottom plate of the forming chamber or aligned with the upper end face of the forming cylinder when 3D printing is completed. When the forming cylinder descends to align with the forming piston inside it, a powder-containing space with the upper end faces of the forming cylinder and the forming piston as the bottom surface is formed inside the powder cleaning outer cylinder. A powder suction port is provided on the side wall of the powder cleaning outer cylinder, and the vacuum cleaner can suck the powder in the powder-containing space through the powder suction port.

[0005] As a further improvement of the invention, a plurality of powder suction ports are arranged on the peripheral side walls of the outer purifying powder cylinder. The plurality of powder suction ports are evenly spaced in the width direction and the height direction of the side wall of the outer purifying powder cylinder. A plurality of vacuum cleaners are respectively and hermetically connected to each powder suction port through anti-static hoses.

[0006] As a further improvement of the invention, an air supply port is provided on the side wall of the outer purifying powder cylinder. The air supply port is located above the powder suction port. A protective gas filtering device is provided on the vacuum cleaner. The protective gas filtering device of the vacuum cleaner can filter and separate the protective gas mixed in the powder. A air supply pipe is further provided on the vacuum cleaner. The air supply pipe is hermetically connected to the air supply port on the side wall of the outer purifying powder cylinder. The vacuum cleaner can send the protective gas filtered by the protective gas filtering device back into the interior of the outer purifying powder cylinder through the air supply pipe and the air supply port.

[0007] As a further improvement of the invention, a longitudinally downward extending guide rail is fixedly provided on the lower side surface of the bottom plate of the forming chamber. The outer side wall of the outer purifying powder cylinder can move linearly up and down along the guide rail.

[0008] As a further improvement of the invention, a packing sealing groove is formed on the upper end surface of the outer purifying powder cylinder. The packing sealing groove is filled with a sealing packing. The upper end surface of the outer purifying powder cylinder is kept sealed with the lower side surface of the bottom plate of the forming chamber through the sealing packing.

[0009] As a further improvement of the invention, the cross sections of the outer purifying powder cylinder, the forming cylinder and the forming piston are all square. The driving device of the purifying powder cylinder is at least four cylinders. The cylinder bodies of the cylinders are fixedly installed on the frame of the 3D printing device. The piston rods of at least four cylinders are respectively fixedly connected to the peripheral side walls of the outer purifying powder cylinder.

[0010] As a further improvement of the invention, a dust collecting box is further provided on the outer side wall of the outer purifying powder cylinder. The vacuum cleaner can discharge the powder it sucks into the dust collecting box for collection.

[0011] As a further improvement of the invention, at least one circle of sealing rings is provided on the outer circumference of the upper end of the forming cylinder. The outer circumference side wall of the forming cylinder is in sealing contact with the inner side wall of the outer purifying powder shell through the sealing rings.

[0012] As a further improvement of the invention, the lifting driving device of the forming cylinder includes a forming cylinder bottom support plate, a forming cylinder lifting guide rail, a forming cylinder driving motor and a forming cylinder driving lead screw. The forming cylinder lifting guide rail is fixedly installed on the frame of the 3D printing device. The forming cylinder bottom support plate is slidably installed on the forming cylinder lifting guide rail up and down. The forming cylinder bottom support plate supports the lower end surface of the cylinder bottom of the forming cylinder. The forming cylinder driving lead screw is axially stopped and circumferentially rotatable and installed on the frame of the 3D printing device. The forming cylinder driving lead screw extends in the vertical direction, and the forming cylinder driving lead screw is movably screwed to the forming cylinder bottom support plate. The forming cylinder driving motor drives the forming cylinder driving lead screw to rotate through a reducer.

[0013] As a further improvement of the invention, a forming cylinder driving column is fixedly arranged in the frame of the 3D printing device. An avoidance hole is arranged on the bottom of the forming cylinder. The forming cylinder driving column is a hollow cylindrical structure. A piston driving column is fixedly arranged at the lower end of the forming piston. The piston driving column can move up and down through the avoidance hole and the inner hole of the forming cylinder driving column. The piston driving device includes a piston driving motor, a piston driving speed reducer and a piston driving screw rod. The piston driving motor and the piston driving speed reducer are both fixedly installed on the forming cylinder driving column. The piston driving screw rod is movably screwed with the piston driving column. The piston driving screw rod is axially stopped and can rotate circumferentially in the forming cylinder driving column. And the piston driving motor drives the piston driving screw rod to rotate intermittently through the piston driving speed reducer.

[0014] The beneficial technical effects of the present invention are as follows: The present invention cancels the horizontal movement function system of the forming cylinder, simplifies the transmission chain of the forming cylinder, and is more beneficial to ensuring the centering accuracy of the forming cylinder. By arranging a powder cleaning outer cylinder outside the forming cylinder, the upper end of the powder cleaning outer cylinder is hermetically connected with the lower side surface of the bottom plate of the forming chamber to form a powder-containing space. After the workpiece is formed, the forming cylinder drops until its upper opening is flush with the upper plane of the forming piston, exposing the workpiece and the residual powder around it. The residual powder is quickly sucked away by the vacuum cleaner through the powder suction port, achieving the purpose of automatic powder cleaning. And during the powder cleaning process, the powder-containing space inside the powder cleaning outer cylinder remains in a sealed state, which can prevent oxygen from entering the powder cleaning outer cylinder and causing an explosion. After the powder cleaning is completed, the powder cleaning outer cylinder descends to be flush with the upper end surface of the forming cylinder and the upper cross section of the piston, vacating the working space height for accessing the forming bottom plate and the formed workpiece. When taking the workpiece, the forming cylinder does not need to move horizontally, and the translation workpiece taking device can easily take out the workpiece together with the forming bottom plate. At the same time, a new forming bottom plate is replaced to prepare for the next 3D printing. After the workpiece is taken out by an external force, under the action of the air cylinder, the powder cleaning outer cylinder returns to be flush with the lower side surface of the forming chamber bottom plate and is pressed tightly, and the forming cylinder resets and fills with protective gas, completing an action cycle. The present invention can realize the intelligent and automatic powder cleaning and workpiece taking of the 3D printing device, save labor, reduce the cost of the 3D printing device, and improve the overall production efficiency. Description of the Drawings

[0015] Figure 1 It is a schematic diagram of the powder cleaning and workpiece taking principle of the invention;

[0016] Figure 2 It is a three-dimensional structure diagram of the invention;

[0017] Figure 3 It is a three-dimensional sectional view of the structural principle of the present invention. Detailed Embodiments

[0018] Embodiment: A box-type flour cleaning system with a stationary formed part, comprising a forming chamber 10, a forming cylinder 3, a forming piston 7, and a piston driving device 8. The forming piston 7 is circumferentially stopped and axially slidable up and down and is installed in the forming cylinder 3. The piston driving device 8 drives the forming piston 7 to move up and down. It further includes a forming cylinder lifting driving device, a flour cleaning outer cylinder 5, a flour cleaning cylinder driving device 4, and a dust collector 9. The forming cylinder 3 is installed below the forming chamber 10 and can move up and down. The forming cylinder lifting driving device can drive the forming cylinder 3 to move up and down. After the forming cylinder 3 rises, its upper end can be hermetically inserted into the opening of the forming chamber bottom plate 1 and aligned and connected with the working plane on the upper side of the forming chamber bottom plate 1, or can be hermetically pressed against the lower surface of the forming chamber bottom plate 1 and the inner side surface of the forming cylinder 3 is aligned and connected with the inner side wall of the opening of the forming chamber bottom plate 1. After the forming cylinder descends, its upper end plane can be aligned and connected with the upper end face of the forming piston 7 when 3D printing is completed. The flour cleaning outer cylinder 5 is installed directly below the forming chamber 10 and can move up and down. The upper end face of the flour cleaning outer cylinder 5 can be in sealed contact with the lower side surface of the bottom plate of the forming chamber 10, and the inner side surface of the flour cleaning outer cylinder 5 is in sealed contact with the outer side surface of the forming cylinder 3. The flour cleaning cylinder driving device 4 can drive the flour cleaning outer cylinder 5 to move up and down so that its upper end face is in sealed contact with the lower side surface of the bottom plate of the forming chamber 10 or is aligned and connected with the upper end face of the forming cylinder 3 when 3D printing is completed. When the forming cylinder descends to align with the forming piston inside it, a powder-containing space with the upper end faces of the forming cylinder and the forming piston as the bottom surface is formed inside the flour cleaning outer cylinder 5. A powder suction port 12 is provided on the side wall of the flour cleaning outer cylinder 5, and the dust collector 9 can suck away the powder 13 in the powder-containing space through the powder suction port 12.

[0019] When the 3D printing device finishes laser printing, the forming cylinder drops until its upper opening is flush with the upper plane of the forming piston. The workpiece 11 and the residual powder 13 around it enter the powder-containing space of the flour cleaning outer cylinder 5. The dust collector 9 is turned on, and the residual powder 13 is sucked away from the powder suction port 12 of the flour cleaning outer cylinder 5 by the dust collector 9. The complete workpiece is exposed. At this time, the flour cleaning cylinder driving device 4 is started, and the flour cleaning outer cylinder 5 descends to align with the upper end face of the forming cylinder 3, creating a working space height for accessing the forming bottom plate 14 and the formed workpiece. The workpiece and the forming bottom plate are taken out together by a translation workpiece-taking device, and a new forming bottom plate is replaced onto the forming piston. The flour cleaning cylinder driving device 4 and the forming cylinder lifting driving device respectively drive the flour cleaning outer cylinder 5 and the forming cylinder 3 to rise and reset, preparing for the next 3D printing. The above mechanism realizes rapid powder cleaning and workpiece taking of the 3D printing device, greatly improves the efficiency of powder cleaning and workpiece taking, avoids manual operation, and during the powder cleaning and workpiece taking process, the forming cylinder does not need to move horizontally to the outside of the 3D printing device, and the forming cylinder only needs to retain the function of moving up and down. It simplifies the transmission chain of the forming cylinder and is more beneficial to ensuring the centering accuracy of the forming cylinder.

[0020] A number of powder suction ports 12 are arranged on the side walls around the outer powder cleaning cylinder 5. The number of powder suction ports 12 are evenly spaced in the width direction and height direction of the side wall of the outer powder cleaning cylinder 5. A number of vacuum cleaners 9 are respectively and hermetically connected to each powder suction port 12 through anti-static hoses. In this way, no matter what height the upper plane of the forming cylinder is located at, there is a corresponding powder suction port 12, and dust is sucked from all four sides of the outer powder cleaning cylinder 5, making it easier to suck up the residual powder completely. Furthermore, the powder 13 in the powder-containing space can be completely emptied. The industrial vacuum cleaner 9 is connected to the powder suction port 12 on the side wall of the outer powder cleaning cylinder 5 through an anti-static hose, and the anti-static hose moves up and down together with the outer powder cleaning cylinder 5, and is reliably grounded to prevent explosion during movement and powder cleaning.

[0021] An air supply port 15 is provided on the side wall of the outer powder cleaning cylinder 5. The air supply port 15 is located above the powder suction port 12. A protective gas filtering device is provided on the vacuum cleaner 9. The protective gas filtering device of the vacuum cleaner 9 can filter and separate the protective gas mixed in the powder 13. A air supply pipe is also provided on the vacuum cleaner 9. The air supply pipe is hermetically connected to the air supply port 15 on the side wall of the outer powder cleaning cylinder 5. The vacuum cleaner 9 can send the protective gas filtered by the protective gas filtering device back into the interior of the outer powder cleaning cylinder 5 through the air supply pipe and the air supply port 15. The vacuum cleaner 9 sends the filtered protective gas back into the powder cleaning space through the air supply pipe and the air supply port 15, which can ensure that no oxygen enters (mixes in) during the powder suction process to prevent explosion and ensure the safety of powder suction. The air supply port 15 is preferably multiple and arranged horizontally at intervals to form a row, and is provided above the powder suction ports 12 arranged in an array.

[0022] A longitudinally downward extending guide rail 2 is fixedly provided on the lower side surface of the bottom plate of the forming chamber 10. The outer side wall of the outer powder cleaning cylinder 5 can move linearly up and down along the guide rail 2. The powder cleaning cylinder guiding system connected integrally with the bottom plate of the forming chamber avoids the multi-reference design of the whole machine, realizes a unified central reference point, provides a unified reference for the design, manufacture, measurement and assembly of the whole machine, facilitates the work such as manufacturing and debugging, and improves the efficiency.

[0023] A packing seal groove is formed on the upper end surface of the outer powder cleaning cylinder 5. The packing seal groove is filled with a sealing packing. The upper end surface of the outer powder cleaning cylinder 5 is kept sealed with the lower side surface of the bottom plate of the forming chamber 10 through the sealing packing. Ensure the sealing performance between the outer powder cleaning cylinder 5 and the bottom plate of the forming chamber, and prevent air from entering the powder-containing space during powder suction, which may lead to an explosion.

[0024] The cross-sections of the external purifying powder cylinder 5, the forming cylinder, and the forming piston 7 are all square. The purifying powder cylinder driving device 4 is at least four cylinders. The cylinder bodies of the cylinders are fixedly installed on the 3D printing equipment frame 22, and the piston rods of at least four cylinders are respectively fixedly connected to the peripheral side walls of the external purifying powder cylinder 5. It is optimal that the four cylinders are evenly and symmetrically distributed around the external purifying powder cylinder 5. For example, the piston rods of the four-cylinder cylinders are fixedly connected to the middle positions of the peripheral side walls of the purifying powder outer shell, or symmetrically distributed at the four corners of the external purifying powder cylinder 5.

[0025] A dust collection box 6 is also provided on the outer side wall of the external purifying powder cylinder 5. The vacuum cleaner 9 can discharge the sucked powder 13 into the dust collection box 6 for collection. The sucked powder 13 is uniformly collected by the dust collection box 6. When the powder 13 in the dust collection box 6 reaches a certain amount, it can be opened or removed from the external purifying powder cylinder 5 to uniformly process the collected powder 13.

[0026] At least one circle of sealing rings 16 is provided on the outer circumference of the upper end of the forming cylinder. The outer circumferential side wall of the forming cylinder is in sealed contact with the inner side wall of the purifying powder outer shell through the sealing rings 16. The above structure enables the upper end of the forming cylinder 3 to be radially sealed and combined with the upper opening of the bottom plate of the forming chamber 10, and the upper end of the external purifying powder cylinder 5 to be end-face sealed and combined with the lower side of the bottom plate of the forming chamber 10. At the same time, the upper end of the forming cylinder 3 is radially sealed and combined with the inner side of the external purifying powder cylinder 5. This ensures the sealing of the forming cylinder 3 in the forming chamber 10 during the workpiece forming process, ensuring high-quality workpiece forming. After the workpiece is formed, a powder-containing space sealed and communicated with the forming chamber 10 is also formed inside the external purifying powder cylinder 5, realizing the rapid suction of the powder 13 without gas leakage, improving the safety of powder purification, and also avoiding the dispersion of metal powder 13 in the workshop, further ensuring safe production.

[0027] The forming cylinder lifting driving device includes a forming cylinder bottom 21 support plate 17, a forming cylinder lifting guide rail 18, a forming cylinder driving motor 19, and a forming cylinder driving lead screw 20. The forming cylinder lifting guide rail 18 is fixedly installed on the frame 22 of the 3D printing equipment. The forming cylinder bottom 21 support plate 17 is slidably installed on the forming cylinder lifting guide rail 18. The forming cylinder bottom 21 support plate 17 supports the lower end face of the bottom of the forming cylinder. The forming cylinder driving lead screw 20 is axially fixed and rotatable in the circumferential direction and is installed on the frame 22 of the 3D printing equipment. The forming cylinder driving lead screw 20 extends in the vertical direction, and the forming cylinder driving lead screw 20 is movably screwed with the forming cylinder bottom 21 support plate 17. The forming cylinder driving motor 19 drives the forming cylinder driving lead screw 20 to rotate through a speed reducer. The forming cylinder driving motor 19 can realize the rising or falling of the forming cylinder by forward and reverse rotation. When rising, the forming cylinder is lifted by the forming cylinder bottom 21 support plate 17. When falling, using the own mass of the forming cylinder, the forming cylinder bottom 21 support plate 17 reduces the supporting force to realize the falling of the forming cylinder. This structure can effectively reduce the energy input and save energy.

[0028] A forming cylinder driving column 23 is also fixedly arranged in the frame 22 of the 3D printing device. An avoidance hole 24 is arranged on the bottom 21 of the forming cylinder. The forming cylinder driving column 23 is a hollow cylindrical structure. A piston driving column 25 is fixedly arranged at the lower end of the forming piston. The piston driving column 25 can move up and down through the avoidance hole 24 and the inner hole of the forming cylinder driving column 23. The piston driving device 8 includes a piston driving motor 26, a piston driving speed reducer and a piston driving screw. The piston driving motor 26 and the piston driving speed reducer are both fixedly installed on the forming cylinder driving column 23. The piston driving screw is movably screwed with the piston driving column 25. The piston driving screw is axially stopped and circumferentially rotatably installed in the forming cylinder driving column 23. And the piston driving motor 26 drives the piston driving screw to rotate intermittently through the piston driving speed reducer. The forming cylinder driving column 23 is used on the one hand to install the piston driving motor 26, the piston driving speed reducer and the piston driving screw for driving the forming piston to move up and down, so as to hide the piston driving device 8 in the forming cylinder, saving space. At the same time, the upper end of the forming cylinder driving column 23 can also be used to limit the descending distance of the forming cylinder, preventing the forming cylinder from descending too far and separating from the powder cleaning outer shell.

Claims

1. A box-type purifying system with a stationary forming part, comprising a forming chamber (10), a forming cylinder (3), a forming piston (7) and a piston driving device (8). The forming piston is circumferentially stopped and axially slidable up and down and is installed in the forming cylinder. The piston driving device drives the forming piston to move up and down. It is characterized in that: It further includes a forming cylinder lifting drive device, a flour cleaning outer cylinder (5), a flour cleaning cylinder drive device (4) and a dust collector (9). The forming cylinder is movably mounted below the forming chamber in a liftable manner. The forming cylinder lifting drive device can drive the forming cylinder to move up and down. After the forming cylinder rises, its upper end can be inserted into the opening of the bottom plate (1) of the forming chamber in a sealed manner and aligned and connected with the working plane on the upper side of the bottom plate of the forming chamber, or can be tightly abutted against the lower surface of the bottom plate of the forming chamber in a sealed manner and the inner side surface of the forming cylinder is aligned and connected with the inner side wall of the opening of the bottom plate of the forming chamber. After the forming cylinder descends, its upper end plane can be aligned and connected with the upper end face of the forming piston when 3D printing is completed. The flour cleaning outer cylinder is movably mounted directly below the forming chamber. The upper end face of the flour cleaning outer cylinder can be in sealed contact with the lower side face of the bottom plate of the forming chamber, and the inner side surface of the flour cleaning outer cylinder is in sealed contact with the outer side surface of the forming cylinder. The flour cleaning cylinder drive device can drive the flour cleaning outer cylinder to move up and down so that its upper end face is in sealed contact with the lower side face of the bottom plate of the forming chamber or is aligned and connected with the upper end face of the forming cylinder when 3D printing is completed. When the forming cylinder descends to be aligned with the forming piston inside it, a powder-containing space with the upper end faces of the forming cylinder and the forming piston as the bottom surface is formed inside the flour cleaning outer cylinder. A powder suction port (12) is provided on the side wall of the flour cleaning outer cylinder, and the dust collector can suck away the powder (13) in the powder-containing space through the powder suction port.

2. The box-type purifying system with a stationary formed part as described in claim 1, wherein: A plurality of powder suction ports are arranged on the peripheral side walls of the flour cleaning outer cylinder. The plurality of powder suction ports are evenly spaced along the width direction and the height direction of the side wall of the flour cleaning outer cylinder. A plurality of dust collectors are respectively hermetically connected to each powder suction port through anti-static hoses.

3. The box-type purifying system with a stationary formed part as described in claim 1 or 2, characterized in that: An air supply port (15) is provided on the side wall of the flour cleaning outer cylinder. The air supply port is located above the powder suction port. A protective gas filtering device is provided on the dust collector. The protective gas filtering device of the dust collector can filter and separate the protective gas mixed in the powder. A air supply pipe is also provided on the dust collector. The air supply pipe is hermetically connected to the air supply port on the side wall of the flour cleaning outer cylinder. The dust collector can send the protective gas filtered by the protective gas filtering device back into the interior of the flour cleaning outer cylinder through the air supply pipe and the air supply port.

4. The box-type purifying system with a stationary formed part as described in claim 1, characterized in that: A longitudinally downward extending guide rail (2) is fixedly provided on the lower side face of the bottom plate of the forming chamber. The outer side wall of the flour cleaning outer cylinder can move up and down linearly along the guide rail.

5. The box-type purifying system with a stationary formed part as claimed in claim 1, wherein: A packing sealing groove is formed on the upper end face of the flour cleaning outer cylinder. The packing sealing groove is filled with sealing packing. The upper end face of the flour cleaning outer cylinder is kept sealed with the lower side face of the bottom plate of the forming chamber through the sealing packing.

6. The box-type purifying system with a stationary formed part as claimed in claim 4 or 5, characterized in that: The cross sections of the flour cleaning outer cylinder, the forming cylinder and the forming piston are all square. The flour cleaning cylinder drive device is at least four cylinders. The cylinder bodies of the cylinders are fixedly installed on the frame of the 3D printing device. The piston rods of at least four cylinders are respectively fixedly connected to the peripheral side walls of the flour cleaning outer cylinder.

7. The box-type purifying system with a stationary formed part as described in claim 1, characterized in that: A dust collection box (6) is further provided on the outer side wall of the flour cleaning outer cylinder. The dust collector can discharge the powder it sucks into the dust collection box for collection.

8. The box-type purifying system with a stationary formed part as claimed in claim 1, wherein: At least one ring of sealing rings (16) is provided on the outer circumference of the upper end of the forming cylinder. The outer circumference side wall of the forming cylinder is in sealed contact with the inner side wall of the flour cleaning outer shell through the sealing ring.

9. The box-type purifying system with a stationary formed part as described in claim 1, characterized in that: The forming cylinder lifting drive device includes a forming cylinder bottom support plate (17), a forming cylinder lifting guide rail (18), a forming cylinder drive motor (19), and a forming cylinder drive screw rod (20). The forming cylinder lifting guide rail is fixedly installed on the frame of the 3D printing device. The forming cylinder bottom support plate is slidably installed on the forming cylinder lifting guide rail and supports the bottom end face of the bottom of the forming cylinder (21). The forming cylinder drive screw rod is axially stopped and rotatable in the circumferential direction and is installed on the frame (22) of the 3D printing device. The forming cylinder drive screw rod extends in the vertical direction and is movably screwed to the forming cylinder bottom support plate. The forming cylinder drive motor drives the forming cylinder drive screw rod to rotate through a reducer.

10. The box-type purifying system with the formed part being stationary as claimed in claim 9, wherein: A forming cylinder drive column (23) is also fixedly provided inside the frame of the 3D printing device. An avoidance hole (24) is provided on the bottom of the forming cylinder. The forming cylinder drive column is a hollow cylindrical structure. A piston drive column (25) is fixedly provided at the lower end of the forming piston. The piston drive column can move up and down through the avoidance hole and the inner hole of the forming cylinder drive column. The piston drive device includes a piston drive motor (26), a piston drive reducer, and a piston drive screw rod. The piston drive motor and the piston drive reducer are both fixedly installed on the forming cylinder drive column. The piston drive screw rod is movably screwed to the piston drive column. The piston drive screw rod is axially stopped and rotatable in the circumferential direction and is installed inside the forming cylinder drive column. The piston drive motor drives the piston drive screw rod to rotate intermittently through the piston drive reducer.

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