Aerospace aluminum-magnesium casting core preparation device and method

Abstract

The application discloses a kind of aerospace aluminum magnesium casting core preparation device and method, it is related to casting technical field, device includes double-station sand mixer, large platform, automated negative pressure molding core taking room, track, rotating trolley, sand mold and central control cabinet;The application constructs two core automated production assembly line using single sand mixer, the modeling, hardening and core taking of core are completed in automated negative pressure molding core taking room, full-process automation operation, only 1 operator is needed in central control station position monitoring and operation, saves manpower production cost, core preparation efficiency is high, the strength of prepared core, good performance, batch production quality is stable, equipment floor space is small.Modification material can be added to modify during sand mixing process according to the demand of aerospace casting core, and the hardening gas in the automated negative pressure molding core taking room can be sucked out in time during core making process and harmless treatment, no odor during the whole process, no environmental pollution.

Description

Technical Field

[0001] This invention relates to the field of casting technology, and in particular to an apparatus and method for preparing cores for aerospace aluminum-magnesium castings. Background Technology

[0002] To reduce the weight of spacecraft, aluminum and magnesium alloy castings are widely used. These castings are largely formed using sand casting with anti-gravity technology, and the requirements for dimensional accuracy, surface quality, and internal quality are high. Strict requirements are also placed on the surface quality, dimensional accuracy, physicochemical properties (strength, gas emission, and collapsibility) of the mold, as well as batch production stability.

[0003] Resin binder sands used in casting can be classified according to the chemical structure of the binder, including furan resin sand, phenolic resin sand, phenol-urethane resin sand, polyol-urethane resin sand, alkyd-oil-urethane resin sand, epoxy resin sand, acrylic (salt) resin sand, epoxy-propylene-based polyurethane resin sand, and polyvinyl alcohol resin sand, etc. Based on their molding and core-making processes, they can be further classified into acid (ester or amine) self-hardening cold box method, hot (warm) box method, shell method, gas-hardening cold box method, and drying method, etc. Among these, the self-hardening cold box method using furan resin sand is currently the main forming method for aerospace casting molds in China. However, the self-hardening cold box method using furan resin sand has a long hardening time, and the mold strength and demolding time are greatly affected by ambient temperature and humidity. The final strength of the sand core is relatively high, while its collapsibility and disintegration are relatively low, which can easily lead to defects such as hot cracking in aerospace aluminum-magnesium alloy castings, resulting in low production efficiency.

[0004] The gas-hardening cold box process is an energy-saving and efficient molding and core-making process. Resin sand is catalyzed or hardened by gas or aerosol, forming instantaneously at room temperature. Core sand production allows for longer molding times and shorter demolding times, resulting in high productivity and suitability for mass core production. The castings exhibit high dimensional accuracy, making the gas-hardening cold box process widely used in the automotive, tractor, internal combustion engine, and locomotive industries. However, conventional gas-hardening cold box processes require significant manual labor and dedicated equipment and facilities for each step, including sand mixing, filling, blowing, demolding, and core removal. This leads to high labor and facility costs, insufficient production efficiency, and poor mold quality stability. Furthermore, the resin and hardening gases easily enter the air and are difficult to remove, causing environmental pollution and producing a strong, irritating odor.

[0005] The self-hardening cold box process cannot meet the batch production efficiency and stability requirements of aerospace aluminum-magnesium alloy castings, while the gas-hardening cold box process has high site, personnel and equipment costs, significant environmental pollution, harsh working conditions and low mold quality stability. Summary of the Invention

[0006] The purpose of this invention is to provide a device and method for preparing aerospace aluminum-magnesium casting cores, in order to solve the problems existing in the prior art. The device of this invention has high integration, small footprint, high batch production efficiency and quality stability of cores, low environmental pollution, and can also modify the mold, adjust the overall strength, collapsibility and collapse of the mold, and prepare high-quality molds that meet the forming requirements of aerospace castings.

[0007] To achieve the above objectives, the present invention provides the following solution: This invention provides a device for preparing cores for aerospace aluminum-magnesium castings, including a dual-station sand mixer, a large platform, an automated negative pressure molding and core-taking room, a track, a rotary trolley, sand molds, and a central control cabinet; The central control cabinet consists of a central control computer and a PLC electrical control system. The central control cabinet can communicate and control the dual-station sand mixer, large platform, automated negative pressure molding core sampling room and rotary trolley in real time. The main body of the dual-station sand mixer is a double-arm resin sand mixer. A diversion valve is installed at the bottom outlet of the dual-station sand mixer. The valve port of the diversion valve is connected to the sand injection pipe in the automated negative pressure molding core taking room. The diversion valve is controlled by the central control cabinet and can be opened and closed independently on both sides. The large platform is the installation platform for the hydraulic station, negative pressure extraction pipeline, automated negative pressure molding and core taking room, and dual-station sand mixer of the whole set of equipment. The hydraulic station is connected to all hydraulic cylinders in the equipment and controls their movement. The automated negative pressure molding and core-taking room is provided with a sand injection station, a molding station and a core-taking station arranged sequentially from the inlet to the outlet. The sand injection station is equipped with a sand injection pipe and a sand injection robot. The molding station is equipped with a hardening gas blowing system. The core-taking station is equipped with a core-taking system for separating the sand mold and the sand core. The track is laid along the direction from the inlet to the outlet of the automated negative pressure molding core taking room. The rotary trolley can travel along the track, and the sand mold is set on the rotary trolley. The rotary trolley is equipped with a turntable, and the sand mold is placed on the turntable.

[0008] Preferably, there are two automated negative pressure molding core sampling rooms, and the two valve ports of the diversion valve are respectively connected to the sand injection pipes in the two automated negative pressure molding core sampling rooms.

[0009] Preferably, the hardening gas blowing system includes a hydraulic cylinder and an end plate that is pushed up and down by the hydraulic cylinder. The end plate is used to press the molding sand of the sand mold. The end plate is also equipped with multiple nozzles, which are connected to an external storage tank for storing high-pressure hardening gas.

[0010] Preferably, the core-retrieving system includes a lateral flipping mechanism and an upper and lower core-retrieving mechanism; The lateral flipping mechanism includes hydraulic cylinders and a flipping servo motor respectively disposed on both sides of the automated negative pressure molding core-taking chamber. A clamping rod is rotatably connected to the telescopic rods of the two hydraulic cylinders. The flipping servo motor is fixed on the telescopic rod of one of the hydraulic cylinders. A gear one is disposed on the power output shaft of the flipping servo motor, and a gear two is disposed on a corresponding clamping rod. The gear one and gear two are meshed and connected. The two hydraulic cylinders drive the two clamping rods to extend in opposite directions to clamp the sand mold. The flipping servo motor drives the clamping rod to rotate through gear transmission, so that the sand mold can be flipped. The upper and lower core-taking mechanism includes an upper clamping hydraulic cylinder located at the top of the automated negative pressure molding core-taking chamber and a lower ejection hydraulic cylinder located at the bottom of the automated negative pressure molding core-taking chamber. The upper clamping hydraulic cylinder has a clamping rod at its bottom and the lower ejection hydraulic cylinder has an ejection rod at its top.

[0011] Preferably, the rotating trolley has a through hole for the ejector rod to pass through, and the ejector rod can pass through the rotating trolley to eject the sand mold on the top of the rotating trolley.

[0012] Preferably, the inlet and outlet of the automated negative pressure molding core extraction room are respectively equipped with a front roller shutter door and a rear roller shutter door controlled by the central control cabinet.

[0013] Preferably, the automated negative pressure molding core extraction room is also connected to a negative pressure exhaust pipe, one end of which is connected to the automated negative pressure molding core extraction room, and the other end is connected to an external toxic gas scrubber.

[0014] This invention also provides a method for preparing aerospace aluminum-magnesium casting cores, using the aforementioned aerospace aluminum-magnesium casting core preparation apparatus, comprising the following steps: 1) Preparation of sand molds; After the sand molds are arranged, place them on the rotary table. 2) Sand injection; The rotary trolley transports the sand mold to the entrance of the automated negative pressure molding and core-taking room. The front roller shutter door at the entrance opens, and the rotary trolley enters the automated negative pressure molding and core-taking room, transporting the sand mold to the sand injection station. The diversion valve of the sand mixer opens, and the mixed resin sand is quantitatively delivered to the sand mold through the diversion valve and the sand injection pipe. After delivery, the sand injection robot flattens and compacts the molding sand on the surface of the sand mold, and the rotary trolley transports the sand mold to the molding station. 3) Molding; After the sand mold enters the molding station, the hardening gas blowing system, driven by the hydraulic cylinder, presses the molding sand, and the nozzle connects with the manifold. Hardening gas is then injected into the molding sand through the high-pressure hardening gas storage tank until the sand core is hardened. 4) Taking the shape; After the sand core has hardened, the hardening gas blowing system rises, and the rotary trolley transports the sand mold to the mold removal station. When the sand core is the inner core of the casting, the shape of the inner core determines whether the sand mold needs to be flipped. When the inner core has a bottom dimension larger than the top dimension, or when the draft angle of the sprue mold or riser mold in the outer shape of the casting is opposite to the bottom ejection direction, the sand mold needs to be flipped to ensure smooth ejection of the inner core, sprue mold, or riser mold. The lateral flipping mechanism of the core-taking system operates, with two hydraulic cylinders driving two clamping rods to extend in opposite directions to clamp the sand mold. The flipping servo motor, through gears... The transmission drives the clamping rod to rotate, causing the sand mold to flip. The clamping rod of the upper clamping hydraulic cylinder extends to press the sand mold box frame or the periphery of the mold, and then the ejection rod of the lower ejection hydraulic cylinder ejects the casting core. When the casting core has equal upper and lower dimensions or the top dimension is larger than the bottom dimension, the lateral flipping mechanism does not work. The clamping rod of the upper clamping hydraulic cylinder extends to press the sand mold box frame or the periphery of the mold, and then the ejection rod of the lower ejection hydraulic cylinder passes through the through hole on the rotary table to directly eject the casting core. When the sand core is the shape of the casting, the clamping rod of the upper clamping hydraulic cylinder extends to press the sand core into the sand mold, and the ejecting rod of the lower ejecting hydraulic cylinder passes through the through hole on the rotary table to eject the gating system or riser structure in the sand mold, so that the shape of the casting remains in the sand mold. 5) Transfer; The rear roller shutter door at the exit of the automated negative pressure molding core-taking room opens, and the rotary trolley sends out the sand core and sand mold. Since the core-taking operation has been carried out at the molding station, the sand core and sand mold are loose, so the sand core can be directly removed after being sent out. Then the rotary trolley returns to the initial station, ready to enter the next molding cycle.

[0015] Preferably, in step 4), when the sand core is the shape of the casting, the sand mold is rotated by the turntable on the rotating trolley, and rotated horizontally by the corresponding angle as needed. The ejector rod can eject the gating system or riser structure of different parts of the sand mold one by one in a fixed area.

[0016] The present invention achieves the following beneficial technical effects compared to the prior art: 1. The aerospace aluminum-magnesium casting core preparation device and method provided by the present invention can use a single sand mixing unit. The machine shop built two automated core production lines, and the core molding, hardening and core removal were completed in the same automated negative pressure molding and core removal room, which improved the core preparation efficiency.

[0017] 2. The entire core-making equipment occupies only 1 / 3 to 1 / 4 of the area required for a normal air-hardening cold box process. Furthermore, targeted protective measures can be implemented for the core-making stage, ensuring an odor-free and pollution-free production process, significantly improving the production environment. The prepared cores exhibit excellent strength and performance, the entire process is automated, batch production quality is stable, and the quality of castings is guaranteed to be consistent.

[0018] 3. The entire core production process of this invention requires only one operator to monitor and operate at the central control station, saving labor production costs.

[0019] 4. The core-taking process of this invention can realize multi-directional core extraction and core removal, and the mold can be freely rotated and flipped, which can meet the core-making requirements of various molds and sand cores required for aerospace castings.

[0020] 5. This invention can use a variety of different resins and hardening gases to prepare the core according to the requirements of mold strength, hardness and collapsibility. It can also use modified materials to modify the mold to meet the forming requirements of aerospace castings.

[0021] 6. This invention has no special requirements for mold structure, site, and equipment such as sand mixing and air blowing. Conventional equipment can meet the requirements. It has the advantages of high efficiency, high integration, low cost, and no pollution, and can realize fully automated or human-machine integrated production. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a schematic diagram of the aerospace aluminum-magnesium casting core preparation device of the present invention; Figure 2 This is a schematic diagram of the structure of the dual-station sand mixer in this invention; Figure 3 This is a schematic diagram of the structure of the automated negative pressure molding and core extraction room in this invention; In the diagram: 1-Dual-station sand mixer, 2-Large platform, 3-Automatic negative pressure molding and core taking room, 4-Railway, 5-Central control cabinet, 6-Sand mold, 7-Rotating trolley, 8-Diverter valve, 9-Sand injection pipe, 10-Hydraulic station, 11-Negative pressure exhaust pipe, 12-Hardening gas blowing system, 13-Hydraulic cylinder, 14-Tilting servo motor, 15-Clamping rod, 16-Gear 1, 17-Front roller shutter door, 18-Rear roller shutter door, 19-Gear 2, 20-Upper clamping hydraulic cylinder, 21-Clamping rod, 22-Ejection rod. Detailed Implementation

[0024] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0025] The purpose of this invention is to provide an apparatus and method for preparing aerospace aluminum-magnesium casting cores, so as to solve the problems existing in the prior art.

[0026] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0027] The aerospace aluminum-magnesium casting core preparation device in this embodiment, such as Figures 1-3 As shown, it includes a dual-station sand mixer 1, a large platform 2, an automated negative pressure molding and core-taking room 3, a track 4, a rotary trolley 7, a sand mold 6, and a central control cabinet 5. The main body of the central control cabinet 5 is a central control computer and a PLC electrical control system. The central control cabinet 5 can communicate and control the dual-station sand mixer 1, the large platform 2, the automated negative pressure molding core extraction room 3 and the rotary trolley 7 in real time. The main body of the dual-station sand mixer 1 is a double-arm resin sand mixer. A diversion valve 8 is installed at the bottom outlet of the dual-station sand mixer 1. The valve port of the diversion valve 8 is connected to the sand injection pipe 9 in the automated negative pressure molding core extraction room 3. The diversion valve 8 is controlled by the central control cabinet 5 and can be opened and closed independently on both sides. The large platform 2 is the installation platform for the hydraulic station 10, negative pressure extraction pipeline 11, automated negative pressure molding core extraction room 3 and dual-station sand mixer 1 of the whole set of equipment. The hydraulic station 10 is connected to all hydraulic cylinders in the equipment and controls their movement. The automated negative pressure molding and core-taking room 3 is arranged with a sand injection station, a molding station and a core-taking station in sequence from the inlet to the outlet. The sand injection station is equipped with a sand injection pipe 9 and a sand injection robot. The molding station is equipped with a hardening gas blowing system 12. The core-taking station is equipped with a system 13 for separating the sand mold 6 and the core-taking system 13. Track 4 is laid along the direction from the inlet to the outlet of the automated negative pressure molding core taking room 3. The rotary trolley 7 can travel along track 4. The sand mold 6 is set on the rotary trolley 7. A turntable is set on the rotary trolley 7, and the sand mold 6 is placed on the turntable.

[0028] In this specific embodiment, there are two automated negative pressure molding core sampling rooms 3, and the two valve ports of the diversion valve 8 are respectively connected to the sand injection pipes 9 in the two automated negative pressure molding core sampling rooms 3.

[0029] In this specific embodiment, the hardening gas blowing system 12 includes a hydraulic cylinder and an end plate that is pushed up and down by the hydraulic cylinder. The end plate is used to press the sand of the sand mold 6. The end plate is also equipped with multiple nozzles, which are connected to an external storage tank for storing high-pressure hardening gas.

[0030] In this specific embodiment, the core retrieval system includes a lateral flipping mechanism and an upper and lower core retrieval mechanism; The lateral tilting mechanism includes hydraulic cylinders 13 and tilting servo motors 14 respectively located on both sides of the automated negative pressure molding core-taking room 3. A clamping rod 15 is rotatably connected to the telescopic rod of each of the two hydraulic cylinders 13. The tilting servo motor 14 is fixed on the telescopic rod of one of the hydraulic cylinders 13. A gear 16 is provided on the power output shaft of the tilting servo motor 14, and a gear 29 is provided on the corresponding clamping rod 15. The gear 16 and the gear 219 are meshed and connected. The two hydraulic cylinders 13 drive the two clamping rods 15 to extend in opposite directions to clamp the sand mold 6. The tilting servo motor 14 drives the clamping rod 15 to rotate through gear transmission, so that the sand mold 6 can be tilted. The upper and lower core-taking mechanism includes an upper clamping hydraulic cylinder 20 located at the top of the automated negative pressure molding core-taking chamber 3 and a lower ejection hydraulic cylinder (not shown in the figure) located at the bottom of the automated negative pressure molding core-taking chamber 3. The upper clamping hydraulic cylinder 20 is provided with a clamping rod 21 at the bottom and the lower ejection hydraulic cylinder is provided with an ejection rod 22 at the top.

[0031] In this specific embodiment, the body of the rotary trolley 7 is provided with a through hole for the ejector rod 22 to pass through, and the ejector rod 22 can pass through the body of the rotary trolley 7 to eject the sand mold 6 on the top of the rotary trolley 7.

[0032] In this specific embodiment, the inlet and outlet of the automated negative pressure molding core extraction room 3 are respectively equipped with a front roller shutter door 17 and a rear roller shutter door 18 controlled by the central control cabinet 5.

[0033] In this specific embodiment, the automated negative pressure molding core-taking room 3 is also connected to a negative pressure extraction pipe 11. One end of the negative pressure extraction pipe 11 is connected to the automated negative pressure molding core-taking room 3, and the other end is connected to an external toxic gas scrubber. The automated negative pressure molding core-taking room 3 is always under negative pressure throughout the entire core preparation process, with a vacuum degree of 85~95Kpa. The gas in the core-taking room is continuously extracted to the negative pressure extraction pipe and finally enters the scrubber for harmless treatment.

[0034] This embodiment also provides a method for preparing aerospace aluminum-magnesium casting cores, using the aforementioned aerospace aluminum-magnesium casting core preparation apparatus, including the following steps: 1) Prepare sand mold 6; After placing the sand mold 6, place it on the rotary trolley 7; 2) Sand injection; The rotary trolley 7 transports the sand mold 6 to the entrance of the automated negative pressure molding core-taking room 3. The front roller shutter door 17 at the entrance is opened, and the rotary trolley 7 enters the automated negative pressure molding core-taking room 3, transporting the sand mold 6 to the sand injection station. The diversion valve 8 of the sand mixer is opened, and the mixed resin sand is quantitatively delivered to the sand mold 6 through the diversion valve 8 and the sand injection pipe 9. After the delivery is completed, the sand injection robot pushes and presses the molding sand on the surface of the sand mold 6, and the rotary trolley 7 transports the sand mold 6 to the molding station. 3) Molding; After the sand mold 6 enters the molding station, the hardening gas blowing system 12, driven by the hydraulic cylinder, presses the molding sand, and the nozzle connects with the manifold. Hardening gas is injected into the molding sand through the high-pressure hardening gas storage tank until the sand core is hardened. 4) Taking the shape; After the sand core has hardened, the hardening gas blowing system 12 rises, and the rotating trolley 7 transports the sand mold 6 to the mold removal station; When the sand core is the inner core of the casting, the shape of the inner core determines whether the sand mold needs to be flipped. When the inner core of the casting has a bottom dimension larger than the top dimension, or when the draft angle of the sprue mold or riser mold in the outer shape of the casting is opposite to the bottom ejection direction, the sand mold needs to be flipped in order to allow the inner core, sprue mold, or riser mold to be ejected smoothly. The lateral flipping mechanism of the core-taking system works, with two hydraulic cylinders 13 driving two clamping rods 15 to extend in opposite directions to clamp the sand mold 6. The flipping servo motor 14 is driven by a gear belt. The moving clamping rod 15 rotates, causing the sand mold 6 to flip. The clamping rod 21 of the upper clamping hydraulic cylinder 20 extends and presses the sand mold 6 frame or the mold periphery. Then, the ejector rod 22 of the lower ejector hydraulic cylinder ejects the casting core. When the casting core has equal upper and lower dimensions or the top dimension is larger than the bottom dimension, the lateral flipping mechanism does not work. The clamping rod 21 of the upper clamping hydraulic cylinder 20 extends and presses the sand mold 6 frame or the mold periphery. Then, the ejector rod 22 of the lower ejector hydraulic cylinder passes through the through hole on the rotary carriage 7 and directly ejects the casting core. When the sand core is the shape of the casting, the clamping rod 21 of the upper clamping hydraulic cylinder 20 extends to press the sand core into the sand mold 6, and the ejecting rod 22 of the lower ejecting hydraulic cylinder passes through the through hole on the rotary trolley 7 to eject the gating system or riser structure in the sand mold 6, so that the shape of the casting remains in the sand mold 6. 5) Transfer; The rear roller shutter door 18 at the exit of the automated negative pressure molding core taking room 3 opens, and the rotary trolley 7 sends out the sand core and sand mold 6. Since the core taking operation has been carried out at the molding station, the sand core and sand mold 6 are loose, so the sand core can be directly removed after being sent out. Then the rotary trolley 7 returns to the initial station and prepares to enter the next molding cycle.

[0035] In step 4), when the sand core is the shape of the casting, the sand mold is rotated by the turntable on the rotating trolley 7. It is rotated horizontally by the corresponding angle as needed. The ejector rod can eject the gating system or riser structure of different parts of the sand mold one by one in a fixed area.

[0036] Specific examples are as follows: Example 1: This embodiment describes the preparation process of an external casting mold for a certain type of aerospace flight equipment cabin.

[0037] The specific process is as follows: 1) Preparation of sand mold 6: Arrange the sand mold 6 required for molding on the rotary trolley 7; 2) Sand injection; The rotary trolley 7 transports the sand mold 6 to the front end of the automated negative pressure molding core extraction room 3 on one side. The front roller shutter door 17 is opened, and the rotary trolley 7 transports the sand mold 6 to the sand injection station. The sand mixer diversion valve 8 is opened, and the resin sand is transported to the external casting sand mold 6 through the diversion valve 8 and the sand injection port. Resin component I is phenolic resin, and component II is polyisocyanate. The ratio of the two components is 6:4. After the resin sand is transported, the rotary trolley 7 transports the sand mold 6 to the molding station. 3) Molding: After the sand mold 6 enters the molding station, the hardening gas blowing system 12 presses the molding sand inside the sand mold 6. At the same time, the nozzle is connected to the manifold of the sand mold 6 and the nozzle is connected to the external storage tank for storing high-pressure hardening gas. The hardening gas injected into the molding sand is triethylamine (TEA), the carrier gas is high-purity dry N2, the TEA concentration is 4%, the blowing pressure is 0.5MPa, and the blowing time is 10s. 4) Core removal: After the sand core has hardened, the hardening gas blowing system 12 rises, and the rotary trolley 7 transports the sand mold 6 to the core removal station. The rotation of the rotary trolley 7 and the cooperation of the upper and lower core removal mechanisms are used to push out the gating system or riser structure in the sand mold, so that the sand core remains in the sand mold. 5) Transfer: After the sand core is taken, the roller shutter door 18 of the automated negative pressure molding core taking room 3 is opened, and the rotating trolley 7 sends out the sand core and sand mold 6 and returns to the initial position, ready to enter the next cycle.

[0038] Example 2: This embodiment describes the preparation process of sand cores inside the fuel tank compartment of a certain type of aerospace flight.

[0039] The specific process is as follows: 1) Preparation of sand mold 6: Arrange the sand mold 6 required for molding on the rotary trolley 7; 2) Sand Injection: The rotary trolley 7 transports the sand mold 6 to the front end of the automated negative pressure molding core extraction room 3 on one side. The front roller shutter door 17 is opened, and the rotary trolley 7 transports the sand mold 6 to the sand injection station. The sand mixer diversion valve 8 is opened, and the resin sand is conveyed to the external casting sand mold 6 through the diversion valve 8 and the sand injection port. The amount of furan resin added in the mixed furan resin sand is 2.0%, the amount of silane added is 0.8% of the resin content, and 1% of rubber particles by mass are added. After the furan resin sand is conveyed, the rotary trolley 7 transports the sand mold 6 to the molding station. 3) Molding: After the sand mold 6 enters the molding station, the hardening gas blowing system 12 presses the molding sand inside the sand mold 6. At the same time, the nozzle is connected to the manifold of the sand mold 6 and the nozzle is connected to the external storage tank for storing high-pressure hardening gas. SO2 gas is injected into the molding sand at a speed of 0.5 kg / s, a spraying time of 6 seconds, and a purification time of 1 minute. Wait for the sand core to harden. 4) Core removal: After the sand core has hardened, the hardening gas blowing system 12 rises, and the rotating trolley 7 transports the sand mold 6 to the core removal station. The sand core is ejected by the side flipping mechanism and the upper and lower core removal mechanism, so that the sand core is removed from the sand mold. 5) Transfer: After the sand core is taken, the roller shutter door 18 of the automated negative pressure molding core taking room 3 is opened, and the rotating trolley 7 sends out the sand core and sand mold 6 and returns to the initial position, ready to enter the next cycle.

[0040] This invention has illustrated its principles and implementation methods using specific examples. The descriptions of these embodiments are merely illustrative of the method and its core ideas; furthermore, those skilled in the art will recognize that modifications may be made to the specific implementation methods and application scope based on the principles of this invention. Therefore, the content of this specification should not be construed as limiting the invention.

Claims

1. A device for preparing aerospace aluminum-magnesium casting cores, characterized in that: Includes a dual-station sand mixer, a large platform, an automated negative pressure molding and core-taking room, tracks, a rotary trolley, sand molds, and a central control cabinet; The central control cabinet consists of a central control computer and a PLC electrical control system. The central control cabinet can communicate and control the dual-station sand mixer, large platform, automated negative pressure molding core sampling room and rotary trolley in real time. The main body of the dual-station sand mixer is a double-arm resin sand mixer. A diversion valve is installed at the bottom outlet of the dual-station sand mixer. The valve port of the diversion valve is connected to the sand injection pipe in the automated negative pressure molding core taking room. The diversion valve is controlled by the central control cabinet and can be opened and closed independently on both sides. The large platform is the installation platform for the hydraulic station, negative pressure extraction pipeline, automated negative pressure molding and core taking room, and dual-station sand mixer of the whole set of equipment. The hydraulic station is connected to all hydraulic cylinders in the equipment and controls their movement. The automated negative pressure molding and core-taking room is provided with a sand injection station, a molding station and a core-taking station arranged sequentially from the inlet to the outlet. The sand injection station is equipped with a sand injection pipe and a sand injection robot. The molding station is equipped with a hardening gas blowing system. The core-taking station is equipped with a core-taking system for separating the sand mold / sand core from the mold. The track is laid along the direction from the inlet to the outlet of the automated negative pressure molding core taking room. The rotary trolley can travel along the track, and the sand mold is placed on the rotary trolley. The rotary trolley is equipped with a turntable, and the sand mold is placed on the turntable. The core-retrieving system includes a lateral flipping mechanism and an upper and lower core-retrieving mechanism; The lateral flipping mechanism includes hydraulic cylinders and a flipping servo motor respectively disposed on both sides of the automated negative pressure molding core-taking chamber. A clamping rod is rotatably connected to the telescopic rods of the two hydraulic cylinders. The flipping servo motor is fixed on the telescopic rod of one of the hydraulic cylinders. A gear one is disposed on the power output shaft of the flipping servo motor, and a gear two is disposed on a corresponding clamping rod. The gear one and gear two are meshed and connected. The two hydraulic cylinders drive the two clamping rods to extend in opposite directions to clamp the sand mold. The flipping servo motor drives the clamping rod to rotate through gear transmission, so that the sand mold can be flipped. The upper and lower core-taking mechanism includes an upper clamping hydraulic cylinder located at the top of the automated negative pressure molding core-taking chamber and a lower ejection hydraulic cylinder located at the bottom of the automated negative pressure molding core-taking chamber. The upper clamping hydraulic cylinder has a clamping rod at its bottom and the lower ejection hydraulic cylinder has an ejection rod at its top.

2. The aerospace aluminum-magnesium casting core preparation device according to claim 1, characterized in that: There are two automated negative pressure molding core sampling rooms, and the two valve ports of the diversion valve are respectively connected to the sand injection pipes in the two automated negative pressure molding core sampling rooms.

3. The aerospace aluminum-magnesium casting core preparation device according to claim 1, characterized in that: The hardening gas blowing system includes a hydraulic cylinder and an end plate that is pushed up and down by the hydraulic cylinder. The end plate is used to press the molding sand of the sand mold. The end plate is also equipped with multiple nozzles, which are connected to an external storage tank for storing high-pressure hardening gas.

4. The aerospace aluminum-magnesium casting core preparation device according to claim 1, characterized in that: The rotating trolley has a through hole for the ejector rod to pass through, and the ejector rod can pass through the rotating trolley to eject the sand mold on the top of the rotating trolley.

5. The aerospace aluminum-magnesium casting core preparation device according to claim 1, characterized in that: The inlet and outlet of the automated negative pressure molding core extraction room are respectively equipped with a front roller shutter door and a rear roller shutter door, which are controlled by the central control cabinet.

6. The aerospace aluminum-magnesium casting core preparation device according to claim 1, characterized in that: The automated negative pressure molding and core-taking room is also connected to a negative pressure exhaust pipe. One end of the negative pressure exhaust pipe is connected to the automated negative pressure molding and core-taking room, and the other end is connected to an external toxic gas scrubber.

7. A method for preparing aerospace aluminum-magnesium casting cores, using the aerospace aluminum-magnesium casting core preparation apparatus according to any one of claims 1-6, characterized in that, Includes the following steps: 1) Preparation of sand molds; After the sand molds are arranged, place them on the rotary table. 2) Sand injection; The rotary trolley transports the sand mold to the entrance of the automated negative pressure molding and core-taking room. The front roller shutter door at the entrance opens, and the rotary trolley enters the automated negative pressure molding and core-taking room, transporting the sand mold to the sand injection station. The diversion valve of the sand mixer opens, and the mixed resin sand is quantitatively delivered to the sand mold through the diversion valve and the sand injection pipe. After delivery, the sand injection robot flattens and compacts the molding sand on the surface of the sand mold, and the rotary trolley transports the sand mold to the molding station. 3) Molding; After the sand mold enters the molding station, the hardening gas blowing system, driven by the hydraulic cylinder, presses the molding sand, and the nozzle connects with the manifold. Hardening gas is then injected into the molding sand through the high-pressure hardening gas storage tank until the sand core is hardened. 4) Taking the shape; After the sand core has hardened, the hardening gas blowing system rises, and the rotary trolley transports the sand mold to the mold removal station. When the sand core is the inner core of the casting, the shape of the inner core determines whether the sand mold needs to be flipped. When the inner core has a bottom dimension larger than the top dimension, or when the draft angle of the sprue mold or riser mold in the outer shape of the casting is opposite to the bottom ejection direction, the sand mold needs to be flipped to ensure smooth ejection of the inner core, sprue mold, or riser mold. The lateral flipping mechanism of the core-taking system operates, with two hydraulic cylinders driving two clamping rods to extend in opposite directions to clamp the sand mold. The flipping servo motor, through gears... The transmission drives the clamping rod to rotate, causing the sand mold to flip. The clamping rod of the upper clamping hydraulic cylinder extends to press the sand mold box frame or the periphery of the mold, and then the ejection rod of the lower ejection hydraulic cylinder ejects the casting core. When the casting core has equal upper and lower dimensions or the top dimension is larger than the bottom dimension, the lateral flipping mechanism does not work. The clamping rod of the upper clamping hydraulic cylinder extends to press the sand mold box frame or the periphery of the mold, and then the ejection rod of the lower ejection hydraulic cylinder passes through the through hole on the rotary table to directly eject the casting core. When the sand core is the shape of the casting, the clamping rod of the upper clamping hydraulic cylinder extends to press the sand core into the sand mold, and the ejecting rod of the lower ejecting hydraulic cylinder passes through the through hole on the rotary table to eject the gating system or riser structure in the sand mold, so that the shape of the casting remains in the sand mold. 5) Transfer; The rear roller shutter door at the exit of the automated negative pressure molding core-taking room opens, and the rotary trolley sends out the sand core and sand mold. Since the core-taking operation has been carried out at the molding station, the sand core and sand mold are loose, so the sand core can be directly removed after being sent out. Then the rotary trolley returns to the initial station, ready to enter the next molding cycle.

8. The method for preparing aerospace aluminum-magnesium casting cores according to claim 7, characterized in that: In step 4), when the sand core is the shape of the casting, the sand mold is rotated by the turntable on the rotating trolley. It is rotated horizontally by the corresponding angle as needed. The ejector rod can eject the gating system or riser structure of different parts of the sand mold one by one in a fixed area.

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