Dynamic oxygen exhaust sealing system of sintered neodymium iron boron forming equipment and control method

Abstract

The invention discloses a dynamic oxygen exhaust sealing system of sintered neodymium iron boron forming equipment and a control method, and belongs to the technical field of neodymium iron boron forming. The system comprises a system bin, a forming bin and a discharging bin, the forming bin and the discharging bin are arranged on the inner side of the system bin, and the system bin, the forming bin and the discharging bin are each provided with a visual feedback sealing device, an oxygen content sensor and an oxygen exhaust port; ndFeB is formed through the forming bin, enters the discharging bin through the system bin and is discharged through the discharging bin. The sealing system further comprises a main gas supply pipe, an auxiliary gas supply pipe and an emergency gas supply pipe, the main gas supply pipe and the emergency gas supply pipe communicate with the system bin, the forming bin and the discharging bin correspondingly, and the main gas supply pipe is in a normally-open state and used for providing continuous nitrogen with the first flow for the system bin, the forming bin and the discharging bin correspondingly. According to the method, a low-oxygen environment can be maintained in the neodymium iron boron forming process, and the production quality of products is guaranteed while the cost is saved.

Description

Technical Field

[0001] This invention belongs to the field of NdFeB forming technology, specifically relating to a dynamic oxygen degassing and sealing system and control method for sintered NdFeB forming equipment. Background Technology

[0002] Sintered NdFeB permanent magnets are currently the highest-performance permanent magnets, widely used in motors, wind power generation, medical devices, and consumer electronics. Their forming process is a crucial step in producing high-performance magnets, primarily involving powder metallurgy technology, including alloy melting, powder preparation, orientation forming, sintering, and post-processing. During the sintering process, a low-oxygen environment is critical for ensuring product quality. In the NdFeB forming process, a significant oxygen rebound during the discharge stage directly leads to a decline in the material's performance. Existing sealing structures lack a real-time and effective early warning mechanism, increasing production risks. Because current technologies fail to effectively address the problem of instantaneous oxygen rebound, maintaining a low-oxygen environment in critical stages such as discharge is difficult, increasing equipment manufacturing costs and maintenance complexity. Summary of the Invention

[0003] In view of this, the purpose of this invention is to provide a dynamic oxygen degassing and sealing system and control method for sintering NdFeB molding equipment, which can maintain a low-oxygen environment during the NdFeB molding process, thereby saving costs while ensuring product quality.

[0004] To achieve the above objectives, the present invention provides the following technical solution: This invention discloses a dynamic oxygen venting and sealing system for a sintered NdFeB molding equipment, comprising a system chamber, a molding chamber and a discharge chamber located inside the system chamber. Each of the system chamber, molding chamber, and discharge chamber is equipped with a visual feedback sealing device, an oxygen content sensor, and an oxygen vent. After NdFeB is formed in the molding chamber, it enters the discharge chamber through the system chamber and is discharged through the discharge chamber. The sealing system also includes a main gas supply pipe, an auxiliary gas supply pipe, and an emergency gas supply pipe. The main gas supply pipe and the emergency gas supply pipe are respectively connected to the system chamber, molding chamber, and discharge chamber. The main gas supply pipe is normally open and is used to provide a continuous first flow rate of nitrogen to the system chamber, molding chamber, and discharge chamber. When the oxygen content reaches a threshold, the emergency gas supply pipe is used to provide a second flow rate of nitrogen to the system chamber, molding chamber, and discharge chamber. The auxiliary gas supply pipe is connected to the molding chamber and is used to provide a third flow rate of nitrogen to the molding chamber.

[0005] Furthermore, the main gas supply pipe, auxiliary gas supply pipe, and emergency gas supply pipe are installed at the top of the system. The oxygen vents are arranged at even intervals along the vertical direction. A push plate is also installed inside the system chamber. The edge of the push plate slides and seals with the inner wall of the system chamber. The push plate is connected to a pushing device that drives the push plate to move up and down. The edge of the push plate has a notch for making way for the forming chamber and the discharge chamber.

[0006] Furthermore, an adsorption chamber is formed on the inner side of the pusher plate, and the adsorption chamber is filled with deoxygenating material. An axial flow fan is connected to the side of the adsorption chamber. The axial flow fan is connected to a first air-gathering channel through a first channel. The first air-gathering channel is connected to a plurality of first oxygen-absorbing holes, which are evenly distributed on the upper surface of the pusher plate. A second air-gathering channel is connected to the lower side of the adsorption chamber through a second channel. The second air-gathering channel is connected to a plurality of second oxygen-absorbing holes, which are evenly distributed on the lower surface of the pusher plate.

[0007] Furthermore, the push plate includes an upper plate and a lower plate joined together. A lower groove is formed on the lower side of the upper plate, and an upper groove is formed on the upper side of the lower plate. The upper groove and the lower groove are combined to form the adsorption cavity.

[0008] Furthermore, the system compartment has through holes installed on its side walls, and rubber gloves are installed at the through holes. The rubber gloves can be folded up to the outside of the system compartment.

[0009] Furthermore, during the gas supply process, the formula for calculating the nitrogen compensation amount is Q=0.0245·V·ΔC / ln(P1 / P2), where Q is the nitrogen compensation amount, V is the corresponding volume of the chamber, ΔC is the change in oxygen concentration, and P1 / P2 is the pressure ratio between the chamber and the outside environment.

[0010] Furthermore, an operating platform is installed at the bottom of the system compartment. A central hole is opened in the middle of the push plate to allow the operating platform to pass. Multiple rectangular blocks are arranged in an array inside the central hole. An elastic tension tube is sealed between two adjacent rectangular blocks and between the rectangular blocks and the push plate. The elastic tension tube is filled with magnetorheological fluid. A coil corresponding to the magnetorheological fluid and an electromagnetic control system connected to the coil are installed on the outside of the elastic tension tube.

[0011] Furthermore, the side wall of the system compartment is provided with protrusions, and the edge of the push plate is provided with an opening groove corresponding to the protrusion. Several slide plates are evenly distributed in the horizontal direction in the opening groove. The lower edge of the slide plate is provided with a wedge-shaped surface. An elastic sealing block is fixed to the outer end of the slide plate. Adjacent slide plates are slidably sealed together. The slide plate is also slidably sealed together with the push plate. The slide plate is connected to the push plate through an elastic support device. The elastic support device is used to provide longitudinal elastic support force to the slide plate.

[0012] A dynamic oxygen removal control method for sintering NdFeB molding equipment employs a sealing system as described above. During normal production, the main gas supply pipe is normally open, providing a continuous first flow rate of nitrogen to the system chamber, molding chamber, and discharge chamber to maintain an oxygen content of <50ppm within the system. When the oxygen content reaches a threshold, an emergency gas supply pipe provides a second flow rate of nitrogen to the system chamber, molding chamber, and discharge chamber to rapidly reduce the oxygen content near the discharge port and suppress oxygen rebound. An auxiliary gas supply pipe is connected to the molding chamber to provide a third flow rate of nitrogen. The sealing effect is monitored in real time through a visual feedback sealing device, and the nitrogen flow rate is adjusted based on the feedback data.

[0013] The beneficial effects of this invention are as follows: This invention discloses a dynamic oxygen desiccation and sealing system and control method for sintering NdFeB molding equipment. This system enables control of oxygen content during the NdFeB molding process, reducing downtime and improving equipment smoothness during operation. By maintaining the NdFeB molding space in a low-oxygen environment at all times, costs are saved while ensuring product quality. Attached Figure Description

[0014] To make the objectives, technical solutions, and beneficial effects of this invention clearer, the following figures are provided for illustration: Figure 1 This is a schematic diagram of the sealing system of the present invention; Figure 2 This is a schematic diagram of the internal structure of the system warehouse of the present invention; Figure 3 This is a diagram showing the distribution of the pipelines; Figure 4 This is a schematic diagram of the push plate structure; Figure 5 This is a schematic diagram showing the distribution of rectangular blocks; Figure 6 A diagram illustrating the clearance for the rectangular block; Figure 7 This is a schematic diagram of the adsorption cavity structure; Figure 8 for Figure 4 Enlarged view of point A in the middle; Figure 9 for Figure 5 Enlarged view of point B in the middle; Figure 10 for Figure 7 Enlarged view of point C in the middle.

[0015] The following are labeled in the attached diagram: System compartment 1, Forming compartment 2, Discharge compartment 3, Oxygen outlet 4, Main air supply pipe 5, Auxiliary air supply pipe 6, Emergency air supply pipe 7, Push plate 8, Pushing device 9, Notch 10, Adsorption chamber 11, Axial flow fan 12, First channel 13, First air collection channel 14, First oxygen intake hole 15, Second channel 16, Second air collection channel 17, Second oxygen intake hole 18, Upper plate 19, Lower plate 20, Through hole 21, Rubber glove 22, Operating platform 23, Center hole 24, Rectangular block 25, Elastic tension tube 26, Coil 27, Protrusion 28, Opening groove 29, Slide plate 30, Wedge-shaped surface 31, Elastic sealing block 32, Elastic support device 33. Detailed Implementation

[0016] like Figures 1-10 As shown, this invention discloses a dynamic oxygen venting and sealing system for a sintered NdFeB molding equipment. The system includes a system chamber 1, a molding chamber 2 located inside the system chamber 1, and a discharge chamber 3. The chambers are relatively sealed, with the chamber doors opened only during NdFeB transfer. Each of the system chamber 1, molding chamber 2, and discharge chamber 3 is equipped with a visual feedback sealing device, an oxygen content sensor, and an oxygen vent 4. The oxygen content sensor utilizes existing technology to detect the oxygen content within each chamber. The visual feedback sealing device also employs existing technology and is used for real-time monitoring of the sealing effect.

[0017] After being formed in the forming chamber 2, the neodymium iron boron enters the discharge chamber 3 through the system chamber 1 and is discharged through the discharge chamber 3. The sealing system also includes a main gas supply pipe 5, an auxiliary gas supply pipe 6, and an emergency gas supply pipe 7. The main gas supply pipe 5 and the emergency gas supply pipe 7 are connected to the system chamber 1, the forming chamber 2, and the discharge chamber 3, respectively. The main gas supply pipe 5 is in a normally open state and is used to provide a continuous first flow of nitrogen to the system chamber 1, the forming chamber 2, and the discharge chamber 3. The first flow rate is 20-30 L / min. When the oxygen content reaches the threshold, the emergency gas supply pipe 7 is used to provide a second flow of nitrogen to the system chamber 1, the forming chamber 2, and the discharge chamber 3. The outlet of the emergency gas supply pipe 7 is equipped with a solenoid valve, which can precisely control the flow rate. The second flow rate is 80-100 L / min, which can quickly reduce the oxygen content. The auxiliary gas supply pipe 6 is connected to the molding chamber 2, and the gas supply pressure is 0.1-0.15MPa. It provides nitrogen gas at a third flow rate to the molding chamber 2. The auxiliary gas supply pipe 6 can supplement gas under specific working conditions to further optimize the oxygen content.

[0018] This invention continuously fills the system with nitrogen to promote oxygen expulsion, thereby maintaining a low-oxygen environment in the molding space of NdFeB at all times, which saves costs while ensuring product quality.

[0019] As a further improvement to this invention, the main gas supply pipe 5, auxiliary gas supply pipe 6, and emergency gas supply pipe 7 are installed at the top of the system. Due to the light weight of nitrogen, the downward pressure promotes oxygen discharge. Oxygen vents 4 are evenly spaced vertically. To conserve nitrogen, a pusher plate 8 is installed inside the system chamber 1. The pusher plate 8 is used to remove oxygen from the system. The edge of the pusher plate 8 slides and seals against the inner wall of the system chamber 1 to ensure a tight seal. The pusher plate 8 is connected to a pushing device 9 that moves it up and down. The pushing device 9 is a hydraulic cylinder and can be controlled by a controller. Short-term pressure fluctuations are ignored during pushing. The edge of the pusher plate 8 has a notch 10 to allow passage for the forming chamber 2 and the discharge chamber 3. It is understood that pushers 8 of corresponding sizes can also be installed in the forming chamber 2 and the discharge chamber 3 to facilitate oxygen removal. Those skilled in the art will understand this.

[0020] In this embodiment, an adsorption chamber 11 is formed on the inner side of the push plate 8. The adsorption chamber 11 is filled with deoxygenating material. An axial flow fan 12 is connected to the side of the adsorption chamber 11. The axial flow fan 12 is connected to a first air collection channel 14 through a first channel 13. The first air collection channel 14 is connected to a plurality of first oxygen intake holes 15, which are evenly distributed on the upper surface of the push plate 8. The lower side of the adsorption chamber 11 is connected to a second air collection channel 17 through a second channel 16. The second air collection channel 17 is connected to a plurality of second oxygen intake holes 18, which are evenly distributed on the lower surface of the push plate 8. When the push plate 8 reaches the bottom or top of the system chamber 1, it is prone to dead space due to the influence of air pipes or other equipment. Therefore, the present invention also provides an active air intake device, which uses an axial flow fan 12 to achieve bidirectional air intake and exhaust. For example, when the pusher plate 8 reaches the bottom of the system chamber 1, the second oxygen intake hole 18 draws in air, which is then collected through the second gas collection channel 17 and enters the adsorption chamber 11. After deoxygenation is achieved in the adsorption chamber 11, the air is discharged above the pusher plate 8 through the first oxygen intake hole 15. This invention uses the evenly distributed first and second oxygen intake holes 15 and 18, which can also uniformly adsorb oxygen across the entire planar area, thereby further reducing the oxygen content.

[0021] In this embodiment, the push plate 8 includes an upper plate 19 and a lower plate 20 joined together. A lower groove is formed on the lower side of the upper plate 19, and an upper groove is formed on the upper side of the lower plate 20. The upper and lower grooves combine to form the adsorption cavity 11. The upper plate 19 and the lower plate 20 can be connected and fixed together by through bolts. By providing a detachable upper plate 19 and lower plate 20, disassembly is convenient, thereby allowing timely replacement of the deoxygenating material in the adsorption cavity 11.

[0022] In this embodiment, a through hole 21 is installed on the side wall of the system compartment 1, and a rubber glove 22 is installed at the through hole 21. The rubber glove 22 can be folded over the outside of the system compartment 1 to avoid affecting the movement of the push plate 8. When in use, the rubber glove 22 can be folded over the system compartment 1 to facilitate manual handling of the materials inside the compartment.

[0023] In this embodiment, during the gas supply process, the nitrogen compensation amount of the emergency gas supply pipe 7 is calculated using the formula Q=0.0245·V·ΔC / ln(P1 / P2), where Q is the nitrogen compensation amount, V is the corresponding volume of the chamber, ΔC is the change in oxygen concentration, and P1 / P2 is the pressure ratio between the chamber and the outside environment. This effectively removes oxygen from the chamber.

[0024] In this embodiment, an operating platform 23 is installed at the bottom of the system compartment 1. A central hole 24 is provided in the middle of the push plate 8 to allow the operating platform 23 to pass. Multiple rectangular blocks 25 are arranged in an array within the central hole 24. An elastic tension tube 26 is sealed between adjacent rectangular blocks 25 and between the rectangular blocks 25 and the push plate 8. The elastic tension tube 26 is filled with magnetorheological fluid. A coil 27 corresponding to the magnetorheological fluid and an electromagnetic control system connected to the coil 27 are installed on the outside of the elastic tension tube 26. The electromagnetic control system adopts existing technology. A magnetic field can be generated around the magnetorheological fluid through the coil 27, thereby changing its flow properties. When the push plate 8 moves above the operating platform 23, the electromagnetic control system is activated, causing the magnetorheological fluid in the elastic tension tube 26 to harden. At this time, when the push plate 8 discharges oxygen in the system compartment 1, it can reduce the pressure effect between the rectangular blocks 25. When the pusher plate 8 moves to the bottom of the system compartment 1 until the rectangular block 25 contacts the operating platform 23, it needs to make way for the operating platform 23. At this time, the fluidity of the magnetorheological fluid is increased, which makes the elastic tension tube 26 softer, thereby increasing the oxygen removal volume and reducing the oxygen content in the system.

[0025] In this embodiment, a protrusion 28 is provided on the side wall of the system compartment 1. The protrusion 28 can be a temperature sensor or other monitoring device related to the system. An opening groove 29 corresponding to the protrusion 28 is formed on the edge of the push plate 8. Several sliding plates 30 are evenly distributed laterally within the opening groove 29. By providing multiple sliding plates 30, different shapes of the protrusion 28 can be accommodated. A wedge-shaped surface 31 is formed on the lower edge of the sliding plate 30. An elastic sealing block 32 is fixed to the outer end of the sliding plate 30. Adjacent sliding plates 30 slide and seal against each other, and the sliding plate 30 also slides and seals against the push plate 8. The sliding plate 30 is connected to the push plate 8 through an elastic support device 33, which provides longitudinal elastic support force to the sliding plate 30. In actual use, the push plate 8 moves each sliding plate 30 downwards until the sliding plate 30 contacts the protrusion 28. At this point, the protrusion 28 contacts the wedge-shaped surface 31 of the slide plate 30. As the push plate 8 continues to move downward, the wedge-shaped surface 31 helps drive the slide plate 30 to move longitudinally. After the slide plate 30 moves, it compresses the elastic support device 33, thus making way for the protrusion 28. When the slide plate 30 moves, the elastic support device 33 provides longitudinal elastic support to the slide plate 30, ensuring that the elastic sealing block 32 at the outer end of the slide plate 30 can also make tight contact with the protrusion 28, achieving a good sealing effect. It is understandable that since the push plate 8 passes the protrusion 28 for a short time, the sealing effect between the slide plate 30 and the protrusion 28 does not need to be too strict; a certain level of sealing is sufficient, without significantly affecting the oxygen content.

[0026] A dynamic oxygen removal control method for sintering NdFeB molding equipment employs a sealing system as described above. During normal production, the main gas supply pipe 5 is normally open, providing a continuous first flow rate of nitrogen to the system chamber 1, molding chamber 2, and discharge chamber 3 to maintain the oxygen content in the system <50ppm. When the oxygen content reaches the threshold, the emergency gas supply pipe 7 provides a second flow rate of nitrogen to the system chamber 1, molding chamber 2, and discharge chamber 3 to rapidly reduce the oxygen content near the discharge port and suppress oxygen rebound. The auxiliary gas supply pipe 6 is connected to the molding chamber 2 to provide a third flow rate of nitrogen to the molding chamber 2. The sealing effect is monitored in real time through a visual feedback sealing device, and the nitrogen flow rate is adjusted according to the feedback data.

[0027] The control logic of this invention adopts a three-layer architecture, including a sensing layer, a decision layer, and an execution layer. The sensing layer consists of an oxygen content sensor, a camera, and a pressure sensor, responsible for real-time acquisition of data such as oxygen content, visual feedback on sealing status, and pressure within the molding system. The decision layer uses a PLC comparator with a built-in threshold library to analyze and compare the data acquired by the sensing layer. The execution layer includes solenoid valves, proportional valves, and alarms, which execute corresponding actions according to the instructions from the decision layer, such as adjusting gas flow and issuing alarm signals. The typical operating procedure is as follows: 1. Regular production: The main gas supply pipe 5 continuously supplies gas to maintain the oxygen content in the system at <50ppm, providing a stable low-oxygen environment for NdFeB molding.

[0028] 2. Discharge Trigger: When the discharge operation is performed, the emergency gas supply pipe 7 is activated, and nitrogen gas is injected at a flow rate of 80-100L / min for 12 seconds to quickly reduce the oxygen content near the discharge port and suppress oxygen rebound.

[0029] 3. Real-time calibration: The visual feedback sealing device detects the sealing condition, and the system adjusts the flow rate based on the feedback data to ensure that the sealing effect is always at its best.

[0030] Through actual operation verification, the oxygen content fluctuation of this invention is controlled within 31±4 ppm, and MSA analysis shows good data stability. The equipment has a continuous operating time of 480 hours, and the mean time between failures (MTBF) is improved by 60% compared with traditional equipment, which fully demonstrates the reliability and stability of this invention.

[0031] Finally, it should be noted that the above preferred embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail through the above preferred embodiments, those skilled in the art should understand that various changes can be made to it in form and detail without departing from the scope defined by the claims of the present invention.

Claims

1. A dynamic oxygen degassing and sealing system for a sintering NdFeB forming equipment, characterized in that: The system includes a system chamber, a molding chamber located inside the system chamber, and a discharge chamber. Each of the system chamber, molding chamber, and discharge chamber is equipped with a visual feedback sealing device, an oxygen content sensor, and an oxygen vent. After being formed in the molding chamber, NdFeB magnets enter the discharge chamber through the system chamber and are discharged through the discharge chamber. The sealing system also includes a main gas supply pipe, an auxiliary gas supply pipe, and an emergency gas supply pipe. The main gas supply pipe and the emergency gas supply pipe are connected to the system chamber, molding chamber, and discharge chamber, respectively. The main gas supply pipe is normally open and provides a continuous first flow rate of nitrogen to each of the system chamber, molding chamber, and discharge chamber. When the oxygen content reaches a threshold, the emergency gas supply pipe provides a second flow rate of nitrogen to each of the system chamber, molding chamber, and discharge chamber. The auxiliary gas supply pipe is connected to the molding chamber and provides a third flow rate of nitrogen to the molding chamber.

2. The dynamic oxygen degassing and sealing system for a sintering NdFeB forming equipment according to claim 1, characterized in that: The main gas supply pipe, auxiliary gas supply pipe and emergency gas supply pipe are installed at the top of the system. The oxygen vents are arranged at even intervals along the vertical direction. A push plate is also installed inside the system chamber. The edge of the push plate slides and seals with the inner wall of the system chamber. The push plate is connected to a pushing device that drives the push plate to move up and down. The edge of the push plate has a notch for making way for the forming chamber and the discharge chamber.

3. The dynamic oxygen degassing and sealing system for a sintering NdFeB forming equipment according to claim 2, characterized in that: An adsorption chamber is formed on the inner side of the push plate, and the adsorption chamber is filled with deoxygenating material. An axial flow fan is connected to the side of the adsorption chamber. The axial flow fan is connected to a first air collection channel through a first channel. The first air collection channel is connected to a plurality of first oxygen absorption holes, which are evenly distributed on the upper surface of the push plate. A second air collection channel is connected to the lower side of the adsorption chamber through a second channel. The second air collection channel is connected to a plurality of second oxygen absorption holes, which are evenly distributed on the lower surface of the push plate.

4. The dynamic oxygen degassing and sealing system for a sintering NdFeB forming equipment according to claim 3, characterized in that: The push plate includes an upper plate and a lower plate that are spliced ​​together. A lower groove is formed on the lower side of the upper plate and an upper groove is formed on the upper side of the lower plate. The upper groove and the lower groove are combined to form the adsorption cavity.

5. The dynamic oxygen degassing and sealing system for a sintering NdFeB forming equipment according to claim 1, characterized in that: The system compartment has through holes installed on its side walls, and rubber gloves are installed at the through holes. The rubber gloves can be folded up to the outside of the system compartment.

6. The dynamic oxygen degassing and sealing system for a sintering NdFeB forming equipment according to claim 1, characterized in that: During the gas supply process, the nitrogen compensation amount is calculated using the formula Q=0.0245·V·ΔC / ln(P1 / P2), where Q is the nitrogen compensation amount, V is the corresponding volume of the chamber, ΔC is the change in oxygen concentration, and P1 / P2 is the pressure ratio between the chamber and the outside environment.

7. A dynamic oxygen degassing and sealing system for a sintering NdFeB forming equipment according to any one of claims 1-6, characterized in that: An operating platform is installed at the bottom of the system compartment. A central hole is opened in the middle of the push plate to allow the operating platform to move. Multiple rectangular blocks are arranged in an array inside the central hole. An elastic tension tube is sealed between two adjacent rectangular blocks and between the rectangular blocks and the push plate. The elastic tension tube is filled with magnetorheological fluid. A coil corresponding to the magnetorheological fluid and an electromagnetic control system connected to the coil are installed on the outside of the elastic tension tube.

8. The dynamic oxygen degassing and sealing system for a sintering NdFeB forming equipment according to claim 7, characterized in that: The system compartment has protrusions on its side walls, and the push plate has openings corresponding to the protrusions on its edges. Several slide plates are evenly distributed in the openings along the transverse direction. The lower edge of the slide plate has a wedge-shaped surface, and an elastic sealing block is fixed to the outer end of the slide plate. Adjacent slide plates slide and seal with each other. The slide plates also slide and seal with the push plate. The slide plates are connected to the push plate through an elastic support device, which provides longitudinal elastic support force to the slide plates.

9. A dynamic oxygen removal control method for sintering NdFeB forming equipment, characterized in that: Using the sealing system as described in any one of claims 1-8, during normal production, the main gas supply pipe is in a normally open state, used to provide a continuous first flow of nitrogen to the system chamber, molding chamber, and discharge chamber respectively, maintaining the oxygen content in the system <50ppm; when the oxygen content reaches the threshold, the emergency gas supply pipe is used to provide a second flow of nitrogen to the system chamber, molding chamber, and discharge chamber respectively, rapidly reducing the oxygen content near the discharge port and suppressing oxygen rebound; the auxiliary gas supply pipe is connected to the molding chamber to provide a third flow of nitrogen to the molding chamber; the sealing effect is monitored in real time by a visual feedback sealing device, and the nitrogen flow rate is adjusted according to the feedback data.

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