Rotary switch for crucible printing and printing method

Abstract

The invention provides a rotary switch for crucible printing and a printing method, and mainly relates to the technical field of metal 3D printing equipment. A rotary switch for crucible printing comprises a fixing frame arranged above a crucible, a plurality of evenly-distributed brackets are fixedly installed on the front face of the fixing frame, connecting rods are arranged in the brackets in a penetrating mode, switch rods are fixedly installed at the lower ends of the connecting rods, and square switch plates are fixedly installed at the lower ends of the switch rods. A nozzle plate is fixedly arranged on the top face of the nozzle pressing plate, a liquid drainage hole opposite to the nozzle pressing plate is formed in the center of the top face of the switch hole plate, and a driving assembly for driving the connecting rod to rotate is fixedly installed on one side of the rear face of the fixing frame. The crucible has the beneficial effects that the connecting rod is driven by the driving assembly to drive the switch plate to rotate so as to control the liquid discharging hole to be opened and closed, accurate control over discharging of materials in the crucible is achieved, and the requirements for the material supply opportunity and the supply amount in the printing operation are met.

Description

Technical Field

[0001] This invention mainly relates to the field of metal 3D printing equipment technology, specifically a rotary switch for crucible printing and a printing method. Background Technology

[0002] In the field of liquid metal printing, the crucible, as the core component for storing and transporting liquid metal (such as molten aluminum), has a switching device that directly affects the stability and quality of the liquid metal supply, thus determining the forming effect and yield rate of the printed product. Currently, the liquid metal control switches commonly used in liquid metal printing equipment are mostly of the stopper rod type. The core working principle of this type of switching device is to achieve cooperation through the axial (up and down) reciprocating motion of the stopper rod and the liquid outlet of the crucible. When the stopper rod moves upward, the liquid outlet opens, and the liquid metal flows out from the liquid outlet and is transported to the printing nozzle; when the stopper rod moves downward, the stopper rod tightly fits against the liquid outlet, realizing the blocking of the liquid metal transport, thereby providing a key on / off control function for the liquid metal printing process.

[0003] However, existing stopper-type switches have significant drawbacks in practical applications, negatively impacting the quality of liquid metal and printing results. Specific problems are as follows: Because the stopper rod is controlled by a reciprocating motion, its movement directly acts on the surface of the liquid metal (such as molten aluminum) in the crucible, mechanically damaging the naturally formed oxide protective layer on the surface of the liquid metal. After the oxide layer is damaged, the contact area between the liquid metal and air increases significantly, causing the metal elements to react violently with oxygen and moisture in the air, generating a large amount of metal oxide impurities (i.e., "slagging"). These impurities mix into the liquid metal, not only reducing its purity but also clogging the nozzles and creating printing defects (such as pores and inclusions) during subsequent printing, severely affecting the mechanical properties and appearance quality of the printed product. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a rotary switch for crucible printing, achieved through the following technical solution: A rotary switch for crucible printing includes a fixed frame positioned above the crucible. Several evenly distributed brackets are fixedly mounted on the front of the fixed frame. A connecting rod passes through each bracket and slides within it. A switch rod is fixedly mounted at the lower end of each connecting rod. A square switch plate is fixedly mounted at the lower end of each switch rod. A nozzle pressure plate is fixedly mounted at the bottom of the crucible. A nozzle plate is fixedly mounted on the top surface of the nozzle pressure plate. Several switch hole plates, each corresponding to a nozzle pressure plate, are fixedly mounted inside the crucible. A drain hole, opposite to the nozzle pressure plate, is located at the center of the top surface of each switch hole plate. A drive assembly for rotating the connecting rod is fixedly mounted on one side behind the fixed frame.

[0005] Furthermore, the driving component includes: The cylinder is fixedly mounted on one side of the back of the mounting bracket via a cylinder mounting seat; A swing arm is hinged to the movable end of the cylinder; A push rod is provided at the front end of the swing rod; Y-shaped connectors are fixedly installed on the rear side of the connecting rods. The push rods pass through the openings of the Y-shaped connectors from right to left, and the Y-shaped connectors are all hinged to the push rods.

[0006] Furthermore, the cross-section of the swing rod is U-shaped, and the top and bottom surfaces of the front end of the swing rod are respectively provided with sliding grooves. Limiting rods are slidably installed in the sliding grooves. The end of the limiting rod located inside the swing rod is fixedly connected to the push rod. The limiting rod can slide along the length of the sliding groove, and the push rod can float up and down within the swing rod within a preset distance.

[0007] Furthermore, a counterweight is fixedly installed at the upper end of each connecting rod, and the counterweight does not contact the bracket.

[0008] Furthermore, an electric heating tube is embedded inside the nozzle pressure plate.

[0009] Furthermore, the drain hole includes a central hole and an outlet hole. The central hole is located at the center of the top surface of the switch plate and is coaxial with the switch rod. The outlet holes are diagonally opened on both sides of the central hole and communicate with it. A fixing shaft is fixedly installed on the bottom surface of the switch plate. The fixing shaft is located in the central hole and slides with it.

[0010] Furthermore, one end of the switch plate is provided with a slot and the other end is provided with a block. Two adjacent switch plates are engaged with each other by corresponding blocks and slots. The switch plates located inside the crucible near its side wall are all fixedly connected to the inner wall of the crucible.

[0011] Furthermore, a heat-insulating connecting block is provided between the connecting rod and the switch rod, and the two ends of the heat-insulating connecting block are coaxially fixedly connected to the corresponding ends of the connecting rod and the switch rod, respectively.

[0012] Based on the rotary switch for crucible printing described above, the present invention also provides a printing method, comprising the following steps: S1: Equipment Initialization and Preparation Install the mounting bracket onto the main support of the metal 3D printing equipment, ensuring a secure connection between the bracket and the main support using bolts and other connectors, and that the overall structure is stable. Check the connection status of each component one by one, confirming that the connecting rod and bracket slide smoothly, that there is no looseness or jamming at the hinge points of the drive components, and that the switch plate and switch hole plate fit tightly without obvious gaps. According to the printing requirements, inject the preset amount of liquid metal (such as molten aluminum) into the crucible, avoiding splashing during the injection process. Close the equipment door, and set the target heating temperature of the electric heating tube through the controller's operating interface (determined according to the type of liquid metal and printing process; for example, aluminum alloy printing is usually set to 650-750℃). Start the electric heating tube to preheat the nozzle platen and nozzle plate. The controller monitors the temperature of the nozzle platen in real time through the temperature sensor. After the temperature reaches the target value and remains stable for 5-10 minutes, the equipment enters the printing preparation state.

[0013] S2: Printing Start and Material Control The operator imports the slicing data of the printing model into the controller. The slicing data includes the material supply requirements for each printing stage (such as flow rate and supply time). Based on the slicing data, the controller sends a start signal to the cylinder, controlling the moving end of the cylinder to push or pull the swing rod at a preset speed. The swing rod swings around the hinge point with the cylinder, driving the push rod at the front end to move along a preset trajectory. The push rod synchronously drives each connecting rod to rotate in the bracket through the Y-shaped connecting seat. The connecting rod drives the switch rod and the square switch plate at the lower end to rotate around the fixed axis, causing the liquid outlet hole on the switch plate to be misaligned with the liquid outlet hole on the switch hole plate. The liquid outlet hole opens, and the liquid metal in the crucible flows into the liquid outlet hole through the central hole under the action of gravity. Then, it is evenly discharged to the printing platform through the nozzle plate. The printing platform moves according to the path of the slicing data and the printing operation begins.

[0014] During the printing process, the controller adjusts the extension and retraction of the cylinder's movable end in real time based on the slice data. By controlling the rotation angle of the connecting rod, it changes the degree of misalignment between the switch plate and the liquid outlet, thereby regulating the discharge flow rate of the liquid metal (the greater the misalignment, the greater the flow rate; the smaller the misalignment, the smaller the flow rate), meeting the material supply requirements of different printing areas (such as thin-walled areas and thick-walled areas). At the same time, the counterweight continuously applies downward pressure to the connecting rod under the action of gravity, ensuring that the switch plate and the switch hole plate always remain in contact, preventing liquid metal from leaking from the gap between them, and ensuring printing quality.

[0015] S3: Print pause and interrupt control When printing needs to be paused (e.g., to replace printing consumables or check the flatness of the printing platform) or when the controller detects an anomaly (e.g., the temperature sensor reports that the nozzle platen temperature exceeds the preset range, the pressure sensor reports abnormal liquid metal pressure in the crucible, or a nozzle blockage warning), the controller immediately sends a reverse action signal to the cylinder. The cylinder's moving end moves in the opposite direction, driving the swing rod, push rod, and connecting rod to rotate synchronously in the opposite direction, causing the switch plate to rotate to a position that completely blocks the liquid outlet, thus quickly cutting off the liquid metal supply. At the same time, the controller keeps the electric heating tube running, maintaining the temperature of the nozzle platen and nozzle plate within the target range to prevent residual liquid metal in the nozzle plate from solidifying and clogging the nozzle. After the operator has dealt with the cause of the pause or the anomaly, they can send a resume printing signal through the controller, and the cylinder will drive the switch plate to rotate again to open the liquid outlet, allowing the printing operation to continue.

[0016] S4: Printing End and Equipment Cleanup Once the controller receives all printing instructions for the sliced ​​data and confirms the printing job is complete, it first controls the cylinder to drive the switch plate to rotate to the position where the liquid outlet is completely closed, stopping the supply of liquid metal. Then, the controller gradually reduces the heating power of the electric heating element, causing the nozzle platen and nozzle plate temperature to drop slowly, preventing damage to components due to thermal expansion and contraction caused by a sudden temperature drop. After the temperature sensor indicates that the nozzle platen temperature has dropped below 100℃ (within the safe temperature range), the controller shuts off the electric heating element and issues a printing completion signal. The operator opens the equipment door and carefully removes the printed product using special tools, avoiding damage to the finished product. Deformation or damage; clean the residual liquid metal in the crucible (for recyclable metal, it can be discharged and collected through the crucible's slag outlet; for non-recyclable residue, use a high-temperature cleaning tool to remove it); check the wear and corrosion of components such as the switch plate, switch orifice plate, and nozzle plate. If severe wear, corrosion, or deformation is found on the surface of the components, replace them in time; add high-temperature lubricating oil to all moving parts of the device (such as the mating parts of the connecting rod and the bracket, and the hinge points of the drive assembly) to ensure smooth movement of the components in the next use; after completing all cleaning and maintenance work, turn off the main power supply of the equipment, and the printing process ends.

[0017] Compared with the prior art, the beneficial effects of the present invention are: 1. This device controls the nozzle's on / off state through rotation during use. The drive assembly drives the connecting rod to rotate the switch plate, controlling the opening and closing of the drain hole. This achieves precise control over the discharge of material from the crucible. Compared to the reciprocating motion of traditional stopper-type switches, this significantly reduces mechanical damage to the oxide layer on the surface of the molten aluminum in the crucible, reduces the contact area between the molten aluminum and air, and reduces oxide slag formation at the source. At the same time, it avoids the strong impact of reciprocating motion, preventing impurities in the crucible from being drawn into the molten aluminum and forming inclusions, ensuring the purity of the molten aluminum, providing high-quality raw materials for subsequent printing, significantly reducing printing defects caused by molten metal quality issues, and improving the yield rate of printed products.

[0018] 2. The drive assembly can achieve coordinated operation of multiple sets of switching structures. Combined with the sealing effect of the counterweight and the temperature control of the electric heating tube, it ensures that the liquid metal supply is uniform, continuous and leak-free, effectively avoiding printing defects (such as air holes, inclusions, and nozzle blockage) caused by material supply problems, and significantly improving the pass rate of printed products. The controller's automatic control function can achieve precise adjustment of equipment operating parameters, further ensuring the stability of the printing process. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 This is a schematic diagram of the installation structure of the cylinder of the present invention; Figure 3 This is an exploded view of the assembly structure of the switch hole plate and the switch plate of the present invention; Figure 4 This is a partial cross-sectional view of the assembly structure of the switch hole plate and the switch plate of the present invention; Figure 5 This is a schematic diagram of the assembly structure of the push rod of the present invention; Figure 6 This is a schematic diagram of the assembly structure of the cylinder and the swing rod of the present invention.

[0020] The following are the labels in the attached diagram: 1. Crucible; 2. Nozzle plate; 3. Electric heating tube; 4. Nozzle pressure plate; 5. Switch orifice plate; 6. Switch plate; 7. Switch rod; 8. Heat insulation connecting block; 9. Bracket; 10. Counterweight; 11. Y-type connecting seat; 12. Push rod; 13. Swing rod; 14. Fixing frame; 15. Cylinder; 16. Cylinder mounting seat; 17. Connecting rod; 18. Drain hole; 181. Center hole; 182. Liquid outlet hole; 19. Slide groove; 20. Limiting rod. Detailed Implementation

[0021] The present invention will be further described in conjunction with the accompanying drawings and specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, it should be understood that after reading the teachings of this invention, those skilled in the art can make various alterations or modifications to the invention, and these equivalent forms also fall within the scope defined in this application.

[0022] Example: A rotary switch for crucible printing like Figure 1-6 As shown, a rotary switch for crucible printing has the following specific structure: A fixed frame 14 is installed above the crucible 1. Several evenly distributed brackets 9 are fixedly installed on the front of the fixed frame 14. A connecting rod 17 is inserted through the bracket 9 and slides with the bracket 9. A switch rod 7 is fixedly installed at the lower end of the connecting rod 17. A square switch plate 6 is fixedly installed at the lower end of each switch rod 7. A nozzle pressure plate 4 is fixedly installed at the bottom of the crucible 1. A nozzle plate 2 is fixedly installed on the top surface of the nozzle pressure plate 4. Several switch hole plates 5, each corresponding to a nozzle pressure plate 4, are fixedly installed inside the crucible 1. The switch hole plates 5 are located above the nozzle plates 2, with a certain distance reserved between them. A drain hole 18 is provided at the center of the top surface of the switch hole plate 5, which is opposite to the nozzle pressure plate 4. A drive assembly for driving the connecting rod 17 to rotate is fixedly installed on one side behind the fixed frame 14. The switch rod 7, switch plate 6, and switch hole plate 5 are all made of silicon nitride ceramic material that is resistant to high temperature and aluminum alloy liquid corrosion.

[0023] The working principle described above is as follows: During the 3D printing of aluminum alloy profiles, the fixing frame 14 is installed on the main support of the aluminum alloy profile 3D printing equipment. The fixing frame 14 provides stable support for the entire rotary switch structure. The bracket 9 guides and limits the connecting rod 17, allowing the connecting rod 17 to slide up and down along the bracket 9, thereby ensuring the position of the switch rod 7. The square switch plate 6 at its lower end abuts against the switch hole plate 5. When the drive component is started and drives the connecting rod 17 to rotate, the connecting rod 17 will drive the switch rod 7 fixedly connected at the lower end to rotate synchronously. The switch rod 7 then drives the square switch plate 6 below to rotate. In the closed state... The drain hole 18 at the center of the top surface of the switch plate 5 is in a relative position to the nozzle pressure plate 4. By rotating the switch plate 6, the direction switch plate 6 and the drain hole 18 are misaligned, which can open the drain hole 18. Furthermore, by adjusting the position of the switch plate 6, the open and closed states of the drain hole 18 can be controlled, thereby controlling the flow of material in the crucible 1 from the drain hole 18 to the nozzle plate 2. At the same time, the switch rod 7, the switch plate 6 and the switch plate 5 are made of silicon nitride ceramic material that is resistant to high temperature and aluminum alloy liquid corrosion, which can adapt to the high temperature environment in the aluminum alloy profile printing process and avoid being corroded by aluminum alloy liquid.

[0024] The driving component includes: Cylinder 15, which is fixedly mounted on one side of the mounting bracket 14 via cylinder mounting seat 16; A swing rod 13 is hinged to the movable end of the cylinder 15; Push rod 12, the front end of the swing rod 13 is provided with push rod 12; Y-shaped connector 11, Y-shaped connector 11 is fixedly installed on the rear side of each connecting rod 17, and push rod 12 passes through the opening of Y-shaped connector 11 from right to left, and each Y-shaped connector 11 is hinged to push rod 12.

[0025] The cylinder 15 in the drive assembly is fixed to the rear side of the fixed frame 14 by the cylinder mounting seat 16. When the cylinder 15 is ventilated and working, its movable end will push or pull the swing rod 13 that is hinged to it, so that the swing rod 13 swings around the hinge point. The push rod 12 set at the front end of the swing rod 13 will move with the swing rod 13. Since the push rod 12 passes through the Y-type connecting seat 11 fixed to the rear side of each connecting rod 17 in sequence and is hinged to the Y-type connecting seat 11, the movement of the push rod 12 will drive the Y-type connecting seat 11 to move synchronously, thereby driving the connecting rod 17 to rotate in the bracket 9, and finally realize the rotation of the switch plate 6 to control the opening and closing of the drain hole 18. Using cylinder 15 as the power source, it features fast response speed and stable output force, which can quickly drive the swing rod 13, push rod 12 and connecting rod 17 to move, so that the switch plate 6 can quickly realize the on and off control of the drain hole 18, thereby improving the efficiency of aluminum alloy profile printing operation. Through the transmission structure of the swing rod 13 and the push rod 12, multiple connecting rods 17 can be driven to move synchronously at the same time, ensuring the consistency of the actions of multiple switch plates 6, avoiding uneven material discharge due to asynchronous actions of each switch plate 6, and improving the printing quality of aluminum alloy profiles.

[0026] The swing rod 13 has a U-shaped cross-section, and the top and bottom surfaces of the front end of the swing rod 13 are respectively provided with grooves 19. Limiting rods 20 are slidably installed in the grooves 19. The end of the limiting rod 20 located in the swing rod 13 is fixedly connected to the push rod 12. The limiting rod 20 can slide along the length of the groove 19, and the push rod 12 can float up and down within the swing rod 13 within a preset distance.

[0027] Each of the connecting rods 17 has a counterweight 10 fixedly installed at its upper end, and the counterweight 10 does not contact the bracket 9.

[0028] The swing rod 13 has a U-shaped cross-section, and the grooves 19 on its front top and bottom surfaces provide a sliding track for the limiting rod 20. One end of the limiting rod 20 is fixedly connected to the push rod 12, and the other end is slidably installed in the groove 19. When the swing rod 13 swings and drives the push rod 12 to move, the limiting rod 20 can adapt to the change in the angle between the push rod 12 and the swing rod 13 and slide along the length of the groove 19 to achieve automatic position adjustment and prevent the push rod 12 and the swing rod 13 from getting stuck. At the same time, under the action of the weight of the counterweight 10, the counterweight 10 applies downward pressure to the connecting rod 17, thereby pressing the switch rod 7 against the switch plate 6 at its bottom, so that the switch plate 6 and the switch hole plate 5 are tightly fitted, ensuring the seal of the switch plate 6 on the drain hole 18 and ensuring the stability of the closed or open state of the drain hole 18.

[0029] An electric heating tube 3 is embedded in the nozzle plate 4 and is electrically connected to a power source. When the power is turned on, the electric heating tube 3 generates heat and transfers the heat to the nozzle plate 4, raising its temperature. Since the nozzle plate 4 is fixedly connected to the nozzle plate 2, the heat is further transferred to the nozzle plate 2, thereby heating the nozzle plate 2 and the material flowing through it. This prevents the material from solidifying at the nozzle plate 2 due to low temperature, ensuring that the material can be smoothly discharged from the nozzle plate 2. At the same time, it can preheat the nozzle plate 4 and the nozzle plate 2, improving the printing effect of aluminum alloy profiles. The electric heating element 3 is embedded in the nozzle pressure plate 4. The heating method is direct and efficient, which can quickly heat the nozzle pressure plate 4 and the nozzle plate 2 to the required temperature, ensuring the fluidity of the material at the nozzle plate 2, avoiding nozzle blockage due to material solidification, and ensuring the smooth progress of the printing operation.

[0030] The drain hole 18 consists of a central hole 181 and an outlet hole 182. The central hole 181 is located at the center of the top surface of the switch plate 5 and is coaxial with the switch rod 7. The outlet holes 182 are diagonally located on both sides of the central hole 181 and communicate with the central hole 181. The fixed shaft fixed to the bottom surface of the switch plate 6 is located inside the central hole 181 and is slidably engaged with it. The fixed shaft guides and positions the rotation of the switch plate 6, ensuring that the switch plate 6 rotates stably around the fixed shaft and preventing the switch plate 6 from shifting during rotation, thus improving the accuracy of the on / off control of the outlet hole 182. When the switch plate 6 rotates, it changes its relative position with the outlet hole 182. When the switch plate 6 does not block the outlet hole 182, the material can flow into the outlet hole 182 from the central hole 181 and be discharged. When the switch plate 6 rotates to block the outlet hole 182, the material cannot be discharged from the outlet hole 182, thereby achieving control over the discharge of the material.

[0031] One end of the switch orifice plate 5 has a slot, and the other end has a locking block. During installation, the locking blocks of two adjacent switch orifice plates 5 are engaged with the slot, which allows for the rapid assembly of multiple switch orifice plates 5 within the crucible 1. For switch orifice plates 5 located near their side walls within the crucible 1, the entire assembled switch orifice plate 5 structure can be fixed within the crucible 1 by being fixedly connected to the inner wall of the crucible 1, ensuring that the switch orifice plates 5 will not shift during operation and providing a stable foundation for the switch plate 6 to control material discharge. At the same time, this splicing installation structure facilitates the individual replacement and maintenance of the switch orifice plates 5 in the future, improving the convenience of device maintenance.

[0032] A heat-insulating connecting block 8 is provided between the connecting rod 17 and the switch rod 7. The two ends of the heat-insulating connecting block 8 are coaxially fixedly connected to the corresponding ends of the connecting rod 17 and the switch rod 7, respectively. Since the switch rod 7, switch plate 6 and switch hole plate 5 are in a high-temperature environment during the printing process of crucible 1, heat will be transferred upward through the switch rod 7. The heat-insulating connecting block 8 has good heat insulation performance and can effectively prevent heat from being transferred from the switch rod 7 to the connecting rod 17, thus preventing the connecting rod 17 and the Y-type connecting seat 11, push rod 12, swing rod 13 and cylinder 15 connected to the connecting rod 17 from being damaged or having their performance degraded due to high temperature.

[0033] This solution also includes a controller, the location of which is set by the operator according to the actual situation during operation. The controller is used to control the electrical components used in this solution, including but not limited to cylinders. The controller is an Intel processor, AMD processor, PLC controller, ARM processor, or microcontroller. It is used in conjunction with a motherboard, memory modules, storage media, and power supply, which is AC power or a lithium battery. When a display screen is provided, a display card is also provided. For the operating principle of the controller, please refer to "Principles of Automatic Control", "Principles and Application Simulation Cases of Microcontrollers", and "Principles and Applications of Sensors" published by Tsinghua University Press. Other books in this field can also be consulted. Other automation control and electrical components not mentioned are knowledge well known to those skilled in the art and will not be described in detail here.

[0034] A printing method for a rotary switch used for crucible printing based on the above-mentioned device includes the following specific steps: S1: Equipment Initialization and Preparation. Install the mounting bracket 14 onto the main support of the metal 3D printing equipment using M12 bolts. Use a level to calibrate the mounting bracket 14 to ensure its levelness error is ≤0.1mm / m. Check the graphite bearing between the connecting rod 17 and the bracket 9, apply high-temperature resistant grease to ensure smooth sliding. Check the pins at each hinge point of the drive assembly to confirm that there is no looseness. Close the equipment door, set the target heating temperature of the electric heating tube 3 to 700℃ through the touch screen of the PLC controller, and start the electric heating tube 3. Monitor the temperature in real time through the K-type thermocouple installed in the nozzle pressure plate 4. After the temperature reaches 700℃ and remains stable for 8 minutes, inject 50kg of aluminum alloy liquid into the crucible 1 to enter the printing preparation state.

[0035] S2: Printing Start and Material Control: The slicing data of the aluminum alloy parts (layer thickness 0.2mm, printing speed 50mm / s) is imported into the PLC controller. The controller sends a start signal to the cylinder 15, controlling the moving end of the cylinder 15 to push the swing rod 13 at a speed of 50mm / s. The swing rod 13 drives the push rod 12 to move, driving the three connecting rods 17 to rotate synchronously by 15°. The switch plate 6 and the liquid outlet 182 are misaligned, and the aluminum alloy liquid is discharged through the drain hole 18 and the nozzle plate 2. The printing platform moves according to the slicing path. During the printing process, when printing to the thin-walled area (thickness 2mm), the controller controls the cylinder 15 to adjust the rotation angle of the connecting rod 17 to 10° to reduce the liquid flow rate. When printing to the thick-walled area (thickness 10mm), the rotation angle is adjusted to 20° to increase the liquid flow rate. The counterweight 10 continuously applies downward pressure to the connecting rod 17 to ensure that the switch plate 6 and the switch hole plate 5 are tightly fitted.

[0036] S3: Printing Pause and Interruption Control During the printing process, if the touch screen displays that the nozzle plate 4 temperature has dropped to 680℃ (below the preset range), the controller immediately sends a reverse action signal to the cylinder 15. The moving end of the cylinder 15 moves in the opposite direction, driving the connecting rod 17 to rotate in the opposite direction, and the switch plate 6 rotates to completely block the liquid outlet 182. At the same time, the controller increases the power of the electric heating tube 3 to 2.2kW to accelerate the heating speed. After the temperature rises back to 700℃ and stabilizes, the controller controls the cylinder 15 to drive the switch plate 6 to rotate again to open the liquid outlet 182, and printing continues.

[0037] S4: Printing End and Equipment Finishing After printing is completed, the controller controls the cylinder 15 to drive the switch plate 6 to close the liquid outlet 182. Then, the power of the electric heating tube 3 is gradually reduced to 0. After the temperature of the nozzle pressure plate 4 drops to 80°C, the equipment door is opened, and the aluminum alloy parts are removed using a special clamp. The residual aluminum alloy liquid is discharged and recycled through the slag discharge valve at the bottom of the crucible 1. The surface of the switch plate 6 is inspected. If slight scratches are found, they are repaired by polishing with ceramic polishing paste. High-temperature resistant grease is added to each hinge point of the drive assembly, and the main power of the equipment is turned off.

[0038] In explaining this invention, it should be noted that the terms indicating location are used only for ease of description and understanding, and are not intended to limit the installation location of specific technical features. Other possible installation methods are not excluded.

[0039] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A rotary switch for crucible printing, comprising a mounting bracket (14) disposed above a crucible (1), characterized in that: A number of evenly distributed brackets (9) are fixedly installed on the front of the fixed frame (14). A connecting rod (17) is inserted through the bracket (9). The connecting rod (17) slides with the bracket (9). A switch rod (7) is fixedly installed at the lower end of the connecting rod (17). A square switch plate (6) is fixedly installed at the lower end of each switch rod (7). A nozzle pressure plate (4) is fixedly installed at the bottom of the crucible (1). A nozzle plate (2) is fixedly installed on the top surface of the nozzle pressure plate (4). A number of switch hole plates (5) corresponding one-to-one with the nozzle pressure plate (4) are fixedly installed inside the crucible (1). A drain hole (18) is provided at the center of the top surface of the switch hole plate (5) opposite to the nozzle pressure plate (4). A drive assembly for driving the connecting rod (17) to rotate is fixedly installed on one side behind the fixed frame (14).

2. A rotary switch for crucible printing according to claim 1, characterized in that: The driving component includes: Cylinder (15), the cylinder (15) is fixedly mounted on one side behind the fixing frame (14) by a cylinder mounting seat (16); A swing rod (13) is hinged to the movable end of the cylinder (15). Push rod (12), the front end of the swing rod (13) is provided with push rod (12); Y-type connector (11), Y-type connector (11) is fixedly installed on the rear side of the connecting rod (17), the push rod (12) passes through the opening of the Y-type connector (11) from right to left, and the Y-type connector (11) is hinged to the push rod (12).

3. A rotary switch for crucible printing according to claim 2, characterized in that: The cross-section of the swing rod (13) is U-shaped, and the top and bottom surfaces of the front end of the swing rod (13) are respectively provided with grooves (19). Limiting rods (20) are slidably installed in the grooves (19). One end of the limiting rod (20) located in the swing rod (13) is fixedly connected to the push rod (12). The limiting rod (20) can slide along the length of the groove (19), and the push rod (12) can float up and down in the swing rod (13) within a preset distance.

4. A rotary switch for crucible printing according to claim 3, characterized in that: The upper end of each connecting rod (17) is fixedly equipped with a counterweight (10), and the counterweight (10) and the bracket (9) do not contact each other.

5. A rotary switch for crucible printing according to claim 1, characterized in that: An electric heating tube (3) is embedded in the nozzle pressure plate (4).

6. A rotary switch for crucible printing according to claim 1, characterized in that: The drain hole (18) includes a central hole (181) and an outlet hole (182). The central hole (181) is located at the center of the top surface of the switch plate (5) and is coaxial with the switch rod (70). The two sides of the central hole (181) are respectively diagonally connected to the outlet hole (182). The bottom surface of the switch plate (6) is fixedly installed with a fixing shaft, which is located inside the central hole (181) and slides with it.

7. A rotary switch for crucible printing according to claim 1, characterized in that: One end of the switch hole plate (5) is provided with a slot and the other end is provided with a block. Two adjacent switch hole plates (5) are connected to each other by corresponding blocks and slots. The switch hole plates (5) located inside the crucible (1) near its side wall are all fixedly connected to the inner wall of the crucible (1).

8. A rotary switch for crucible printing according to claim 1, characterized in that: A heat-insulating connecting block (8) is provided between the connecting rod (17) and the switch rod (7). The two ends of the heat-insulating connecting block (8) are coaxially fixedly connected to the corresponding ends of the connecting rod (17) and the switch rod (7), respectively.

9. A rotary switch for crucible printing according to claim 1, characterized in that: The switch rod (7), switch plate (6) and switch hole plate (5) are all made of silicon nitride ceramic material that is resistant to high temperature and aluminum alloy liquid corrosion.

10. A printing method based on the rotary switch for crucible printing according to any one of claims 1-9, characterized in that, Includes the following steps: S1: Equipment Initialization and Preparation Install the fixing frame (14) on the main support of the metal 3D printing equipment to ensure the overall structure is stable; check the connection status of each component, confirm that the connecting rod (17) and the bracket (9) slide smoothly, that there is no jamming at each hinge point of the drive component, and that the switch plate (6) and the switch hole plate (5) fit tightly; inject a preset amount of liquid metal (such as aluminum liquid) into the crucible (1), close the equipment door, set the target heating temperature of the electric heating tube (3) through the controller, start the electric heating tube (3) to preheat the nozzle pressure plate (4) and the nozzle plate (2), monitor the temperature in real time, and enter the printing preparation state after the temperature reaches the preset value and stabilizes; S2: Printing Start and Material Control According to the slicing data of the printed model, the controller sends a start signal to the cylinder (15); the moving end of the cylinder (15) pushes or pulls the swing rod (13) to swing around the hinge point, the swing rod (13) drives the push rod (12) at the front end to move synchronously, the push rod (12) drives each connecting rod (17) to rotate synchronously in the bracket (9) through the Y-type connecting seat (11); the connecting rod (17) drives the switch rod (7) and the square switch plate (6) at the lower end to rotate, so that the switch plate (6) is misaligned with the drain hole (18) on the switch hole plate (5), the drain hole (18) opens, and the liquid metal in the crucible (1) flows through the central hole (18). 1) The liquid flows into the outlet hole (182) and is then discharged to the printing platform through the nozzle plate (2) to start the printing operation; during the printing process, the controller adjusts the action parameters of the cylinder (15) in real time according to the slice data, and changes the degree of misalignment between the switch plate (6) and the outlet hole (18) by controlling the rotation angle of the connecting rod (17), thereby adjusting the discharge flow rate of the liquid metal to meet the material supply requirements of different printing areas; at the same time, the counterweight (10) applies downward pressure to the connecting rod (17) under the action of gravity to ensure that the switch plate (6) and the switch hole plate (5) always remain in contact to avoid liquid metal leakage; S3: Print pause and interrupt control When the printing process needs to be paused (e.g., to replace printing consumables or check equipment status) or when an abnormality occurs (e.g., abnormal temperature or nozzle blockage warning), the controller sends a reverse action signal to the cylinder (15); the cylinder (15) drives the swing rod (13), push rod (12) and connecting rod (17) to move in the opposite direction, causing the switch plate (6) to rotate to the position of completely blocking the drain hole (18), thereby blocking the supply of liquid metal; at the same time, the controller keeps the electric heating tube (3) running, maintains the temperature of the nozzle pressure plate (4) and nozzle plate (2), and prevents residual liquid metal from solidifying and blocking the nozzle; S4: Printing End and Equipment Cleanup After the printing job is completed, the controller first controls the cylinder (15) to drive the switch plate (6) to completely close the drain hole (18) and stop the liquid metal supply; then the electric heating tube (3) is turned off. After the temperature of the nozzle pressure plate (4) and nozzle plate (2) drops to a safe range, the equipment door is opened and the printed product is taken out; the liquid metal remaining in the crucible (1) is cleaned (or the recyclable metal is recycled), the wear and corrosion of the switch plate (6), switch hole plate (5), nozzle plate (2) and other components are checked, and the damaged parts are replaced or maintained to complete the equipment finishing work.

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