A binder jet sand mold 3D printer

Abstract

This invention relates to the field of printing casting technology, and more particularly to a binder jet sand mold 3D printer, comprising a housing, a control panel, a distance sensor one, a distance sensor two, a spraying section, a sand spreading module, a sand dispensing valve section, a premixing section, and a printing work box. The housing includes a housing shell, with a door groove on the front side of the housing shell. A door is slidably connected to the inner side of the door groove, and a door drive mechanism is installed on the front side of the door. Side seats are fixedly connected to the left and right sides inside the housing shell, and mounting grooves are provided on the upper part of the opposite sides of the side seats. In this invention, through the structure of the air delivery guide section, sand storage shell, sand dispensing shell, air guide roller, and air jet section, the sand spreader of the binder jet sand mold 3D printer can efficiently and smoothly discharge and spread the molding sand evenly on the printing work box under the premise that the sand dispensing amount at the sand dispensing port is reduced, so as to avoid the occurrence of empty spreading or local sand shortage caused by blockage.

Description

Technical Field

[0001] This invention relates to the field of printing and casting technology, specifically to a binder jet sand mold 3D printer. Background Technology

[0002] The binder jet sand mold 3D printer is a powder bed additive manufacturing equipment consisting of a sand supply system, a sand spreader, an array of binder nozzles, a liftable molding platform, a waste sand recovery device, and a central control unit. During operation, the sand supply system first quantitatively delivers premixed dry foundry sand containing curing agent to the sand spreader. The sand spreader reciprocates above the molding platform with a crossbeam, evenly spreading the molding sand into a layer of a set thickness. Then, the binder nozzles spray binder within the same stroke according to the slicing data, solidifying the corresponding areas in the sand layer. The molding platform descends by one layer thickness, and the waste sand recovery device sucks back excess sand particles and circulates and sieves them. These steps are repeated layer by layer under the coordination of the control unit until the overall printing of a complex sand core or mold is completed.

[0003] Existing sand mold 3D printers generally use a passive sand-feeding method with a "sand hopper + fixed opening + vibration / scraper". When the molding sand premixed with curing agent enters the sand spreader, its flowability is poor. If the sand discharge opening is reduced, sand particles easily form arch bridges in the hopper, causing intermittent sand flow or even complete blockage, resulting in empty spreading or local sand shortage. To break up sand particle arch bridges, vibratory motors are often installed on the side wall or bottom of the sand hopper, hoping to reduce internal friction of particles and promote smooth sand flow. However, there is mechanical interlocking and friction between molding sand particles, and the vibration energy is insufficient to overcome this bonding, so arch bridges will still repeatedly form. In addition, the vibration direction is mostly horizontal shear, with a large angle with the direction of gravity, resulting in insufficient vertical momentum, making it difficult to "push" out smaller sand particles. Because of the opening, even with added vibration, intermittent sand drop or even complete blockage will frequently occur, resulting in "empty" or localized sand shortages. If the opening is forced to be enlarged to ensure continuous sand supply, the instantaneous sand output will increase sharply. The sand flow will directly impact the sand surface that has been sprayed with binder and preliminarily cured in a columnar shape. During the advancement process, the scraper will squeeze the excess sand clumps forward, generating shearing and peeling effects on the cured thin layer, thereby forming visible misalignment, edge lifting, and local collapse on the surface of the printed layer. This not only causes the thickness of the subsequent sand layer to fluctuate and the interlayer bonding force to decrease, but also causes the cumulative dimensional error of the printed part along the Z direction to increase rapidly, significantly reducing the surface finish and dimensional accuracy of the final mold. Therefore, based on the above problems, a binder-jet sand mold 3D printer is proposed. Summary of the Invention

[0004] The purpose of this invention is to provide a binder jet sand mold 3D printer to solve the problems of existing binder jet sand mold 3D printers, such as poor sand flowability, small sand outlet leading to uneven sand spreading and easy clogging, and excessive sand output due to excessive sand outlet leading to damage to the lower sand layer.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] A binder jet sand-type 3D printer includes a housing, a control panel, a distance sensor one, a distance sensor two, a spraying section, a sand-laying module, a sand-feeding valve section, a premixing section, and a printing work box. The housing includes a housing shell with a door groove on the front side. A door is slidably connected to the inside of the door groove, and a door drive mechanism is installed on the front side of the door. Side seats are fixedly connected to the left and right sides inside the housing shell. Mounting grooves are provided on the upper part of the opposite sides of each side seat. A pair of mounting grooves are provided between the side seats and the housing shell. The inner wall is fixedly connected to a support bar. An installation port is provided on the upper rear left side of the housing. A premixing unit is installed inside the installation port. A control panel is installed on the right side of the front face of the housing. A distance sensor one is installed in the hole on the left rear side of the housing. A distance sensor two is installed in the hole on the left front side of the housing. A spraying unit and a sand-laying module are installed on the upper side of the left and right side seats. A sand-draining valve is installed on the lower side of the sand-draining module. A printing work box is provided on the upper side of the support bar and located below the sand-draining valve.

[0007] Preferably, each of the mounting slots has a Y-axis linear module fixedly connected to its inner side. The sand-laying module includes a support frame mounted on the upper side of a pair of Y-axis linear modules. The inner side of the middle beam plate of the support frame has a through-hole. A shell is installed inside the through-hole. The shell includes a sand storage shell fixedly connected to the inner wall of the through-hole. A feed hopper is fixedly connected to the upper left side of the sand storage shell. A reference block is fixedly connected to the upper side of the feed hopper. Rotary grooves are formed on the front and rear inclined surfaces of the lower part of the sand storage shell. Rotary holes are formed on both sides of the rotary grooves. A sand outlet is formed on the lower side of the sand storage shell. A scraper is fixedly connected to the front and rear inclined surfaces of the lower part of the sand storage shell. The sand storage shell has a sand distribution shell fixedly connected to its inner side, and an air delivery guide is installed on the outer side of the shell. The air delivery guide includes an air pump fixed to the rear side of the sand storage shell. The lower end of the air pump is fixedly connected to a diversion pipe that is arranged in a continuous manner. Air shells fixed to the left and right sides of the sand storage shell are provided on the lower sides of both ends of the diversion pipe. An air inlet groove connected to the diversion pipe is opened on the inner side of each air shell. Air flow channels are opened on the front and rear sides of the lower part of the air inlet groove. Wheel grooves are opened on the opposite sides of the front and rear air flow channels. An air delivery pipe is fixedly connected to the lower side of each air flow channel. A part of an air guide roller is installed in each of the rotating grooves.

[0008] Preferably, the air guide roller includes a roller shell located inside the rotating groove. The inner side of the roller shell has an inner cavity, and the outer side of the inner cavity has a plurality of air guide ports arranged at equal angles. An air filter is fixedly connected to the inner side of each air guide port. A shaft tube passing through the rotating hole and the air shell is fixedly connected to both sides of the roller shell, and the shaft tube is connected to the inner cavity. An impeller located in the wheel groove is fixedly connected to the outer side of each shaft tube. A part of the jet section is installed on the inner side of each air guide roller. The jet section includes a central tube located inside the inner cavity and rotatably connected to the inner wall of the shaft tube. A plurality of interconnected air distribution pipes are fixedly connected to the upper side of the central tube. A flow-limiting shell is fixedly connected to the upper end of each air distribution pipe. A connecting sleeve is fixedly connected to both ends of the central tube, and the connecting sleeve is connected to the upper end of each air delivery pipe.

[0009] Preferably, the door drive mechanism consists of an outer shell, a motor, gears, and a rack. The outer shell is fixed to the front side of the housing. Motors are fixedly connected to both sides of the inner side of the outer shell. Gears are fixedly connected to the ends of the output shafts of the motors. Racks are meshed to the rear sides of the gears, and the racks are fixed to the front side of the door. The width of the door is greater than the width of the printing work box. Distance sensor one and distance sensor two are both set at the same height as the reference block. Distance sensor one is located directly to the left of the sand pipe of the premixing section. The feed hopper is aligned with the premixing section. The sand separating shell consists of an inclined guide shell and several sand separating pipes set at an inclined angle on the front side of the inclined guide shell. An inclined guide groove with a forward inclination is opened on the inner side of the inclined guide shell of the sand separating shell. The sand separating shell is located directly below the feed hopper.

[0010] Preferably, a portion of the impeller is disposed within the airflow guide channel, the air delivery pipe is composed of square connectors on the upper and lower sides and a folded pipe between the connectors, the sleeve is a square sleeve structure, the upper square connectors of the air delivery pipe are all inserted into the inner side of the sleeve, the outer curved surfaces of the air guide rollers are all in contact with the inner wall of the rotating groove, a gap is provided between the front and rear air guide rollers, and the flow limiting shell is a shell plate structure with an opening on the arc-shaped upper arc surface, the upper arc surface of the flow limiting shell is in contact with the upper curved surface of the inner cavity.

[0011] Preferably, each of the air inlet slots has a receiving slot on its lower side, and each receiving slot has a rod channel on its lower side. The upper part of a driving component is installed on the inner side of each air housing. The driving component includes a base rod slidably connected to the rod channel. The lower interior of the base rod has a rod groove with a downward opening. A threaded groove is formed on the side of the rod groove away from the sand storage shell. A fastener is threaded onto the inner side of the threaded groove. An extension rod is slidably connected to the inner side of the rod groove. A pressure guide block located below the air housing is fixedly connected to the lower end of the extension rod. A plug block slidably connected to the receiving slot is fixedly connected to the upper end of the base rod, and the upper end of the plug block is inserted into the inner side of the air inlet slot. A spring is fixedly connected between the lower end face of the plug block and the lower inner wall of the receiving slot. The sand valve unit includes a base plate fixed to the lower side of the sand storage shell. A sink groove is formed on the upper side of the base plate. Track grooves are formed on both the left and right sides of the sink groove. Damping pads are fixedly connected to the upper and lower inner walls of the track grooves. Lower valve plates are slidably connected to the front and rear sides of the sink groove. Upper connecting plates located above the lower valve plates are fixedly connected to the front and rear sides of the sink grooves. Low-elasticity baffles are fixedly connected to the opposing ends of the front and rear upper connecting plates. The lower ends of the low-elasticity baffles are fixedly connected to the opposing ends of the front and rear lower valve plates. Rail rods located inside the track grooves are fixedly connected to the left and right sides of the lower valve plates. Springs are fixedly connected between the opposite sides of the front and rear rail rods and the inner walls of the track grooves. Guide blocks are fixedly connected to the ends of the rail rods away from the lower valve plates.

[0012] Preferably, the upper and lower end faces of the rail rod are in contact with the opposing surfaces of the upper and lower damping pads, the guide blocks are all located on the lower side of the pressure guide block, a gap is provided between the upper end of the extension rod and the upper inner wall of the rod groove, the fastener consists of bolts and damping blocks, the damping blocks of the fastener are in contact with the outer end face of the extension rod, the surface of the extension rod is provided with graduations, the spacing between the front and rear upper connecting plates is the same as the width of the lower sand opening, the upper connecting plates are all located on the front and rear sides of the bottom of the lower sand opening, the low elasticity baffle is located directly below the lower sand opening, and the lowest point of the scraper is lower than the lowest point of the lower sand valve.

[0013] Compared with the prior art, the beneficial effects of the present invention are:

[0014] 1. In this invention, the sand storage shell, sand distribution shell, air guide roller, and air jet section are designed to output molding sand through the sand storage shell. The air guide roller drives the two air guide rollers to rotate in opposite directions and downwards during air delivery. This rotation squeezes the molding sand in the sand storage shell downwards. At the same time, the air jet section delivers air to the air jet section. The air jet section and air guide roller allow the ejected air to continuously blow away the molding sand accumulated in the sand storage shell, making the molding sand in the sand storage shell fluidized. This significantly improves the fluidity of the molding sand. This invention enables the sand spreader of the binder jet sand mold 3D printer to efficiently and smoothly discharge and spread the molding sand evenly on the printing work box when the sand discharge from the lower sand outlet is reduced. This avoids the occurrence of empty spreading or local sand shortage caused by blockage. This invention solves the problems of existing binder jet sand mold 3D printers where the sand spreader has poor molding sand fluidity, an excessively small lower sand outlet leading to uneven sand spreading and easy blockage, and an excessively large lower sand outlet causing excessive sand discharge and thus damaging the lower sand layer.

[0015] 2. In this invention, the gas delivery guide, driving component, and sand discharge valve are designed to automatically push the driving component downward by a fixed dimension during gas delivery. The downward movement of the driving component can cause the sand discharge valve to change from a closed state to an open state through transmission. Since the downward movement dimension of the driving component is fixed, the pressure applied by the pressure guide block of the driving component to the guide block of the sand discharge valve can be adjusted by adjusting the distance between the pressure guide block and the guide block of the sand discharge valve. This allows for adjustment of the distance between the two lower valve plates on the front and rear sides after their opposite displacement, thereby controlling the size of the sand outlet of the sand discharge valve and changing the amount of sand discharged from the outlet. This enables the sand spreader of the binder jet sand mold 3D printer to automatically open or close the sand discharge outlet according to whether sand is being discharged, and the sand discharge amplitude of the sand discharge outlet can be adjusted according to the sand discharge requirements of the printing process. This solves the problem that the sand spreader of the existing binder jet sand mold 3D printer is difficult to flexibly control the opening and closing of the sand discharge outlet and the amount of sand discharged according to actual needs. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0017] Figure 2 For the present invention Figure 1 Schematic diagram of the split structure of the middle box section;

[0018] Figure 3 For the present invention Figure 2 Another perspective on the structure and a further breakdown of the structural diagram;

[0019] Figure 4 This is a schematic diagram of the cross-sectional structure of the box section of the present invention;

[0020] Figure 5 This is a schematic diagram of the disassembled structure of the door drive mechanism of the present invention;

[0021] Figure 6 This is a schematic diagram of the spraying section of the present invention from a tilted, upward view.

[0022] Figure 7 This is a structural schematic diagram of the sand-laying module of the present invention;

[0023] Figure 8 For the present invention Figure 7 A magnified structural diagram at point A;

[0024] Figure 9 This is a schematic diagram of the inclined upward structure of the sand-laying module without support frame of the present invention;

[0025] Figure 10 For the present invention Figure 9 A magnified structural diagram at point B;

[0026] Figure 11 For the present invention Figure 9 Schematic diagram of the split structure of the middle section;

[0027] Figure 12 For the present invention Figure 11 A magnified structural diagram at point C;

[0028] Figure 13 This is a partial cross-sectional view of the air guide roller and the jet section of the present invention;

[0029] Figure 14 This is a schematic diagram of the shell structure from an oblique, upward view.

[0030] Figure 15 This is a partial cross-sectional structural diagram of the shell and the sand-separating shell of the present invention;

[0031] Figure 16 This is a partial cross-sectional view of the gas delivery guide section of the present invention;

[0032] Figure 17 For the present invention Figure 16 A magnified structural diagram at point D;

[0033] Figure 18 This is a partial cross-sectional view of the driving component of the present invention;

[0034] Figure 19 This is a cross-sectional structural schematic diagram of the base rod of the present invention;

[0035] Figure 20 This is a schematic diagram of the split structure of the air guide roller of the present invention;

[0036] Figure 21 This is a schematic diagram of the jet section of the present invention;

[0037] Figure 22This is a schematic diagram of the cross-sectional structure of the lower sand valve part of the present invention;

[0038] Figure 23 This is a side-view cross-sectional structural diagram of the airflow sweeping range at the jet section of the present invention.

[0039] In the diagram: 1. Box section; 11. Box shell; 12. Door groove; 13. Box door; 14. Door drive mechanism; 141. Outer shell; 142. Motor; 143. Gear; 144. Rack; 15. Side seat; 16. Mounting groove; 17. Support bar; 18. Mounting port; 2. Control panel; 3. Distance sensor one; 4. Distance sensor two; 5. Spraying section; 6. Sanding module; 61. Support frame; 62. Port Position; 63. Shell; 631. Sand storage shell; 632. Feed hopper; 633. Reference block; 634. Rotary groove; 635. Rotary hole; 636. Sand outlet; 637. Scraper; 64. Sand distribution shell; 65. Air conveying guide section; 651. Air pump; 652. Diverter pipe; 653. Air shell; 654. Air inlet groove; 655. Airflow guide; 656. Wheel groove; 657. Collection groove; 658. Rod path 659. Air supply pipe; 66. Drive component; 661. Base rod; 662. Plug; 663. Spring 1; 664. Rod groove; 665. Threaded groove; 666. Fastener; 667. Extension rod; 668. Pressure guide block; 67. Air guide roller; 671. Roller shell; 672. Inner cavity; 673. Air inlet; 674. Vent filter; 675. Shaft tube; 676. Impeller; 68. Jet section; 6 81. Central through-pipe; 682. Gas distribution pipe; 683. Flow limiting shell; 684. Connecting sleeve; 7. Lower sand valve section; 701. Base plate; 702. Sink; 703. Rail groove; 704. Damping pad; 705. Rail rod; 706. Guide block; 707. Lower valve plate; 708. Spring 2; 709. Upper connecting plate; 710. Low elasticity baffle; 8. Premix section; 9. Printing work box; 10. Y-axis linear module. Detailed Implementation

[0040] Please see Figure 1-23 The present invention provides a technical solution:

[0041] A binder jet sand-type 3D printer includes a housing 1, a control panel 2, a distance sensor 1 3, a distance sensor 2 4, a spraying section 5, a sand-laying module 6, a sand-feeding valve section 7, a premixing section 8, and a printing work box 9. The housing 1 includes a housing shell 11. A door groove 12 is formed on the front side of the housing shell 11. A door 13 is slidably connected to the inner side of the door groove 12. A door drive mechanism 14 is installed on the front side of the door 13. Side seats 15 are fixedly connected to the left and right sides inside the housing shell 11. Mounting grooves 16 are formed on the upper part of the opposite sides of the side seats 15. A pair of support bars 17 are provided between the side seats 15 and fixedly connected to the rear inner wall of the housing shell 11. An installation opening 18 is formed on the upper rear left side of the housing shell 11. The premixing section 8 is installed inside the installation opening 18. A control panel 2 is installed on the right side of the front face of housing 11. A distance sensor 3 is installed in the hole on the left rear side of housing 11, and a distance sensor 4 is installed in the hole on the left front side of housing 11. A spraying part 5 and a sand-laying module 6 are installed on the upper side of the left and right side seats 15. A sand-draining valve part 7 is installed on the lower side of the sand-laying module 6. A printing work box 9 is set on the upper side of the support bar 17 and located below the sand-draining valve part 7. Y-axis linear modules 10 are fixedly connected to the inner side of the mounting slots 16. The sand-laying module 6 includes a support frame 61 installed on the upper side of a pair of Y-axis linear modules 10. This setting allows the Y-axis linear modules 10 to drive the support frame 61 to move, thereby controlling the movement of the entire sand-laying module 6. A through-hole is opened on the inner side of the middle beam plate of the support frame 61. An opening 62 is provided, and a shell 63 is installed on the inner side of the opening 62. This arrangement allows the support frame 61 to support the shell 63 and maintain its height position. The shell 63 includes a sand storage shell 631 fixedly connected to the inner wall of the opening 62. A feed hopper 632 is fixedly connected to the upper left side of the sand storage shell 631 and is arranged in communication with it. A reference block 633 is fixedly connected to the upper side of the feed hopper 632. Rotary grooves 634 are opened on the front and rear inclined surfaces of the lower part of the sand storage shell 631. Rotary holes 635 are opened on both the left and right sides of the rotary grooves 634. A sand discharge port 636 is opened on the lower side of the sand storage shell 631. Scrapers 637 are fixedly connected to the front and rear inclined surfaces of the lower part of the sand storage shell 631. A sand separating shell 64 is fixedly connected to the inner side of the sand storage shell 631. An air delivery guide section 65 is installed on the outer side of the shell 63. The air delivery guide section 65 includes an air pump 651 fixed to the rear side of the sand storage shell 631. The lower end of the air pump 651 is fixedly connected to a diversion pipe 652 that is arranged in a continuous manner. The lower sides of the left and right ends of the diversion pipe 652 are provided with air shells 653 fixed to the left and right sides of the sand storage shell 631. The inner side of the air shell 653 is provided with an air inlet groove 654 that is connected to the diversion pipe 652. The lower front and rear sides of the air inlet groove 654 are provided with airflow guide channels 655. The back side of the front and rear airflow guide channels 655 is provided with a wheel groove 656. The lower side of the airflow guide channel 655 is fixedly connected with an air delivery pipe 659 that is arranged in a continuous manner. A part of the air guide roller 67 is installed in the rotating groove 634.The air guide roller 67 includes a roller shell 671 located inside the rotating groove 634. An inner cavity 672 is formed inside the roller shell 671, and several air guide ports 673 arranged at equal angles are formed outside the inner cavity 672. A ventilation filter 674 is fixedly connected to the inner side of each air guide port 673. Shaft tubes 675, passing through rotating holes 635 and air shells 653, are fixedly connected to both sides of the roller shell 671, and are connected to the inner cavity 672. Impellers 676, located in wheel grooves 656, are fixedly connected to the outer side of each shaft tube 675. This arrangement allows the air delivery guide section 65 to drive the air guide rollers 67 on both sides to rotate in opposite directions and downwards by air delivery. This rotation forces the molding sand in the sand storage shell 631 downwards. Air jet sections 68 are installed inside the air guide rollers 67. Part of the jet section 68 includes a central pipe 681 located inside the inner cavity 672 and rotatably connected to the inner wall of the shaft tube 675. Several air distribution pipes 682 are fixedly connected to the upper side of the central pipe 681. A flow-limiting shell 683 is fixedly connected to the upper end of the air distribution pipe 682. Both the left and right ends of the central pipe 681 are fixedly connected to connecting sleeves 684, and the connecting sleeves 684 are all connected to the upper end of the air supply pipe 659. This arrangement allows the air supply guide section 65 to deliver airflow into the jet section 68. Through the interaction between the jet section 68 and the continuously rotating air guide roller 67, the ejected airflow continuously blows the molding sand accumulated in the sand storage shell 631, making the molding sand in the sand storage shell 631 into a fluidized state, thereby significantly improving the fluidity of the molding sand.The door drive mechanism 14 consists of an outer shell 141, a motor 142, gears 143, and a rack 144. The outer shell 141 is fixed to the front side of the housing 11. Motors 142 are fixedly connected to both sides of the inner side of the outer shell 141. Gears 143 are fixedly connected to the ends of the output shafts of the motors 142. Racks 144 are meshed with the rear sides of the gears 143, and the racks 144 are fixed to the front side of the door 13. This arrangement allows the door drive mechanism 14 to drive the door 13 to move up and down, thus opening or closing the door 13. The width of the door 13 is larger than the width of the printing workbox 9. This arrangement allows the printing workbox 9 to open when the door 13 is open. The molding box 9 can pass through the door slot 12. Distance sensors 3 and 4 are both set at the same height as the reference block 633. Distance sensor 3 is located directly to the left of the sand pipe of the premixing section 8. The feed hopper 632 is aligned with the premixing section 8. This arrangement ensures that when distance sensor 3 detects the reference block 633, it indicates that the feed hopper 632 of the sand spreading module 6 is precisely aligned with the lower side of the sand pipe of the premixing section 8. At this time, the premixing section 8 can smoothly transport the premixed molding sand through the feed hopper 632 into the sand distribution shell 64 of the sand spreading module 6. The sand distribution shell 64 consists of an inclined guide shell and several sand distribution pipes arranged at an inclined angle on the front side of the inclined guide shell. The sand distribution shell 64 has a forward-inclined guide groove on its inner side, allowing it to guide the molding sand evenly into the sand storage shell 631 in multiple directions, preparing for subsequent sand spreading. The sand distribution shell 64 is located directly below the feed hopper 632, allowing it to transport molding sand into the inner side of the sand distribution shell 64. A portion of the impeller 676 is located within the airflow guide 655, ensuring that airflow through the guide 655 drives the impeller 676 to rotate. The air delivery pipe 659 consists of square connectors on the upper and lower sides and a folded pipe between the connectors. The connecting sleeve 684 is square... The air supply pipe 659 has a square connector on its upper side that is inserted into the inner side of the sleeve 684. This design allows the air supply pipe 659 to position the jet nozzle 68, preventing it from rotating and ensuring that the orientation of the flow-limiting shell 683 remains unchanged. The outer curved surfaces of the air guide rollers 67 are in contact with the inner wall of the rotating groove 634, and there is a gap between the front and rear air guide rollers 67. The flow-limiting shell 683 is a shell plate structure with an opening on its arc-shaped upper surface. The upper arc surface of the flow-limiting shell 683 is in contact with the upper curved surface of the inner cavity 672. This design ensures that the gas inside the flow-limiting shell 683 will not enter the inner cavity 672, but will instead be delivered to the ventilation filter 674.

[0042] like Figures 8-10 , Figure 12 , Figures 17-19 , Figure 22As shown, each air inlet slot 654 has a storage slot 657 on its lower side, and each storage slot 657 has a rod channel 658 on its lower side. The upper part of a drive component 66 is installed inside each air housing 653. The drive component 66 includes a base rod 661 slidably connected to the rod channel 658. The lower interior of the base rod 661 has a rod groove 664 with a downward opening. A threaded groove 665 is provided on the side of the rod groove 664 away from the sand storage shell 631. A fastener 666 is threadedly connected to the inner side of the threaded groove 665. An extension rod 667 is slidably connected to the inner side of the rod groove 664. The lower end of the extension rod 667 is fixedly connected to a component located in the air housing 653. The lower pressure guide block 668 on the 3rd side has a plug 662 fixedly connected to the upper end of the base rod 661 and slidably connected to the storage groove 657. The upper end of the plug 662 is inserted into the inner side of the air inlet groove 654. A spring 663 is fixedly connected between the lower end face of the plug 662 and the lower inner wall of the storage groove 657. The sand valve part 7 includes a base plate 701 fixed to the lower side of the sand storage shell 631. A sink groove 702 is opened on the upper side of the base plate 701. Track grooves 703 are opened on both the left and right sides of the sink groove 702. Damping pads 704 are fixedly connected to the upper and lower inner walls of the track grooves 703. The lower front and rear sides of the sink groove 702 are slidably connected to the lower... The valve plate 707 and the recess 702 are both fixedly connected to upper connecting plates 709 on the upper side of the lower valve plate 707. Low-elasticity baffles 710 are fixedly connected to the opposing ends of the upper connecting plates 709. The lower ends of the low-elasticity baffles 710 are fixedly connected to the opposing ends of the lower valve plates 707. Rail rods 705 are fixedly connected to the left and right sides of the lower valve plate 707, located inside the rail groove 703. Springs 708 are fixedly connected between the opposite sides of the rail rods 705 and the inner wall of the rail groove 703. Guide blocks 706 are fixedly connected to the ends of the rail rods 705 away from the lower valve plate 707. This arrangement enables… When supplying air, the gas guide section 65 can automatically push the drive member 66 to move downward by a fixed dimension. The downward movement of the drive member 66 can cause the sand lowering valve section 7 to change from a closed state to an open state through transmission. Since the downward movement dimension of the drive member 66 is fixed, the degree of pressure applied by the pressure guide block 668 to the guide block 706 of the sand lowering valve section 7 can be adjusted by adjusting the distance between the pressure guide block 668 of the drive member 66 and the guide block 706 of the sand lowering valve section 7. This can then adjust the distance between the two lower valve plates 707 after their opposite displacement, thereby controlling the size of the sand passage of the sand lowering valve section 7 and changing the amount of sand discharged from the sand lowering port 636.The upper and lower end faces of the rail rod 705 are in contact with the opposing surfaces of the upper and lower damping pads 704. This arrangement allows for positioning of the rail rod 705 and the lower valve plate 707, preventing the lower valve plate 707 from shaking due to slight impacts during molding sand pouring. The guide blocks 706 are all located below the pressure guide blocks 668. This arrangement allows the downward movement of the pressure guide blocks 668 to compress the guide blocks 706. A gap is provided between the upper end of the extension rod 667 and the upper inner wall of the rod groove 664. This arrangement allows the extension rod 667 to move upward within the rod groove 664. The fastener 666 consists of bolts and damping blocks. The damping blocks of the fastener 666 are in contact with the outer end face of the extension rod 667. This arrangement allows the fastener 666 to fix the extension rod 667. The extension rod 667 is positioned with graduations on its surface, allowing operators to precisely adjust its insertion position into the rod slot 664. The spacing between the front and rear upper connecting plates 709 is the same as the width of the lower sand inlet 636. The upper connecting plates 709 are positioned on the front and rear sides of the bottom of the lower sand inlet 636, preventing them from blocking it. A low-elasticity baffle 710 is positioned directly below the lower sand inlet 636, allowing it to work with the lower valve plate 707 to block it. The lowest point of the scraper 637 is lower than the lowest point of the lower sand valve section 7, enabling it to level the molding sand passing through the lower sand valve section 7.

[0043] Workflow: The general printing operation of the binder jet sand mold 3D printer is as follows: S1. First, the chamber door 13 is opened through the door drive mechanism 14. Then, the printing work box 9 is transported into the chamber 1 by the intelligent transport carriage, so that the printing work box 9 is placed on a pair of support bars 17, so that the initial height of the printing work box 9 can be determined. Then, the intelligent transport carriage is moved out of the chamber 1, and the chamber door 13 is closed again through the door drive mechanism 14. S2. The position of the sand-laying module 6 is adjusted by the Y-axis linear module 10. In conjunction with the distance sensor 13 and the reference block 633, the displacement of the sand-laying module 6 is determined to be directly below the premixing section 8, ensuring that the molding sand can smoothly enter the sand-laying module 6 later. The premixing section 8 is started to mix the premixed solids. S3. The molding sand containing the binder is fed into the sand-laying module 6; S4. The air guide 65, air guide roller 67 and air jet 68 make the molding sand fluidized in the sand storage shell 631, improving its fluidity. At the same time, the airflow will automatically open the sand discharge valve 7; S5. The horizontal movement of the sand-laying module 6 is controlled by the Y-axis linear module 10, so that the molding sand flows out evenly from the sand discharge port 636 and the open sand discharge valve 7, covering the upper surface of the printing work box 9; During the molding sand flow process, the scraper 637 scrapes the molding sand evenly with its inclined surface design to ensure that the thickness of each layer is uniform; S6. The spraying unit 5 is started, and the nozzle of the spraying unit 5 sprays the binder onto specific areas of the molding sand, so that the molding sand particles in these areas are bonded and cured. S6. After each layer of sanding and spraying is completed, activate the lifting mechanism built into the printing work box 9 to lower the inner plate of the printing work box 9 by one layer thickness, providing space for the next layer of sanding and spraying. Then repeat steps S2, S4, S5, and S6. S7. When all layers are printed, the control panel 2 sends a completion signal, stops all moving parts, and opens the box door 13 through the door drive mechanism 14. The operator can then use the intelligent transport trolley to remove the printing work box 9 from the box 1 to retrieve the printed sand mold. The following is a supplementary description of each step. Note 1: All electrical appliances used in this application are externally powered and centrally controlled through the control panel 2. Note 2: Distance sensor 3 and distance sensor The second 4, in conjunction with the reference block 633, can accurately determine whether the front and rear displacement of the sand-laying module 6 is in place. Only when the sand-laying module 6 is fully in place can the nozzle displacement of the spraying section 5 be activated to spray the adhesive onto the sand layer on the printing work box 9, avoiding the nozzle displacement from hitting the sand-laying module 6. When the distance sensor 3 detects the reference block 633 through distance measurement, it indicates that the feed hopper 632 of the sand-laying module 6 has been accurately aligned with the lower side of the sand pipe of the premixing section 8. At this time, the premixing section 8 can smoothly transport the premixed molding sand through the feed hopper 632 into the sand-distributing shell 64 of the sand-laying module 6. Subsequently, with the help of the multi-directional tilting guide of the sand-distributing shell 64, the molding sand is evenly dispersed and transported into the sand storage shell 631, preparing for subsequent sand-laying.The detailed operation of sand laying in step S3 is as follows: When sand laying is required, the air pump 651 of the air delivery guide section 65 is started through the control panel 2. The start of the air pump 651 will draw gas from the housing 11 and deliver the gas to the air shells 653 on both sides through the diverter pipe 652. As the gas enters the air inlet groove 654 of the air shell 653, the air pressure in the air inlet groove 654 gradually increases. At this time, the airflow will push down the plug 662 of the drive member 66 inserted in the air inlet groove 654, causing it to move downward and thus disengage from the air inlet groove 654, no longer blocking the air inlet groove 654, so that the air inlet groove 654 and the airflow guides 655 on both sides become connected. At the same time, the downward movement of the plug 662 forces the spring The first 663 contracts, pushing the base rod 661, extension rod 667, and pressure guide block 668 downward by a fixed dimension. Under the same airflow pressure, the downward displacement of pressure guide block 668 is fixed. Through the above operation, the air delivery guide part 65 can drive the driving members 66 on both sides to move downward when delivering air. The downward displacement of the driving members 66 on both sides will squeeze the paired guide blocks 706 on both sides of the lower sand valve part 7, forcing the left and right guide blocks 706 to be displaced in opposite directions under pressure. The displacement of the guide blocks 706 drives the lower valve plates 707 on the front and rear sides to move in opposite directions through the rail rod 705. On the one hand, the second spring 708 is compressed and contracted, and on the other hand, the lower end of the low elasticity baffle 710 connected to it moves with the movement of the lower valve plate 707. Finally, a gap appears between the front and rear lower valve plates 707, completing the transition of the lower sand valve 7 from the closed state to the open state. When the air delivery guide section 65 stops delivering airflow, the drive member 66 will move upward and reset due to the elasticity of its spring 663, while the lower sand valve 7 will reset due to the elasticity of its spring 708, causing the lower sand valve 7 to switch back from the open state to the closed state. Since the downward movement dimension of the pressure guide block 668 of the drive member 66 is fixed, the degree of pressure applied by the pressure guide block 668 to the guide block 706 each time can be adjusted by adjusting the gap between the pressure guide block 668 and the guide block 706. This, in turn, can adjust the gap between the two lower valve plates 707 after their opposite displacement, thereby controlling the flow of the lower sand valve 7. The size of the sand inlet changes the amount of sand discharged from the lower sand inlet 636. The actual adjustment operation is as follows: By rotating the fastener 666, the fastener 666 is no longer positioned on the extension rod 667. At this time, the extension rod 667 can be moved by the scale on the extension rod 667 with the rod groove 664 as the guide. This allows for precise adjustment of the position of the pressure guide block 668. This enables the sand spreader of the binder jet sand mold 3D printer to automatically open or close the lower sand inlet 636 according to whether sand is being spread. The sand discharge amplitude of the lower sand inlet 636 can also be adjusted according to the sand spreading needs of printing. This solves the problem that the sand spreader of the existing binder jet sand mold 3D printer is difficult to flexibly control the opening and closing of the lower sand inlet 636 and the amount of sand discharged according to actual needs.The second detailed operation of sand laying in step S3: When the airflow entering the airflow guide 655 passes through the airflow guide 655 and enters the air delivery pipe 659, it will drive the drive impeller 676 of the two side air guide rollers 67 to rotate. The rotation of the drive impeller 676 will drive the shaft tube 675, roller shell 671 and air filter 674 to rotate in the rotating groove 634. Through the above operation, the front and rear side air guide rollers 67 will rotate in opposite directions and downwards. The direction of rotation is as follows: Figure 23 As shown, this rotation method allows the molding sand in the sand storage shell 631 to be extruded downwards. Simultaneously, the air supply pipe 659 delivers the airflow from the airflow guide 655 to the nozzle 684 and the central pipe 681 of the jet section 68. Subsequently, the central pipe 681 distributes the airflow to various distribution pipes 682, which then deliver the airflow to the flow-limiting shell 683. The flow-limiting shell 683 then distributes the airflow to various locations that are displaced by the rotation of the roller shell 671 and are connected to the flow-limiting shell 683. The airflow is connected to the ventilated filter 674 of the flow-limiting shell 683 and discharged through the ventilated filter 674. Since the opening of the flow-limiting shell 683 is angled upwards, the airflow from the ventilated filter 674, which is connected to the flow-limiting shell 683, will be injected into the interior of the sand storage shell 631. Furthermore, due to the continuous circumferential displacement of the ventilated filter 674, the airflow from the ventilated filter 674 will continuously purge the molding sand accumulated inside the sand storage shell 631. The purging range is as follows: Figure 23 As shown, this fluidizes the molding sand in the sand storage shell 631 and maintains its fluidized state, thereby significantly improving the flowability of the molding sand. Through the above operations, the molding sand accumulated in the sand storage shell 631 can flow smoothly out from the sand outlet 636 and the opened sand outlet valve 7 during sand laying. This enables the sand spreader of the binder jet sand mold 3D printer to efficiently and smoothly discharge the molding sand and spread it evenly on the printing work box 9, provided that the sand discharge amount at the sand outlet 636 is reduced. This avoids the occurrence of empty laying or local sand shortage caused by blockage. It solves the problems of existing binder jet sand mold 3D printers where the sand spreader has poor molding sand flowability, the sand outlet 636 is too small, resulting in uneven sand laying and easy blockage, and the sand outlet 636 is too large, resulting in excessive sand discharge and damage to the lower sand layer.

[0044] This article uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only for the purpose of helping to understand the method and core ideas of the present invention. The above are only preferred embodiments of the present invention. It should be noted that due to the limitations of textual expression, and the existence of an infinite number of specific structures, those skilled in the art can make several improvements, modifications, or changes without departing from the principles of the present invention, and can also combine the above technical features in an appropriate manner. These improvements, modifications, changes, or combinations, or the direct application of the inventive concept and technical solution to other situations without modification, should all be considered within the scope of protection of the present invention.

Claims

1. A binder jet sand-type 3D printer, comprising a housing (1), a control panel (2), a distance sensor one (3), a distance sensor two (4), a spraying section (5), a sand-laying module (6), a sand-feeding valve section (7), a premixing section (8), and a printing work box (9), characterized in that: The box section (1) includes a box shell (11). A door groove (12) is provided on the front side of the box shell (11). A box door (13) is slidably connected to the inner side of the door groove (12). A door drive mechanism (14) is installed on the front side of the box door (13). Side seats (15) are fixedly connected to the left and right sides inside the box shell (11). Mounting grooves (16) are provided on the upper part of the opposite sides of the side seats (15). A pair of support bars (17) are provided between the side seats (15) and fixedly connected to the rear inner wall of the box shell (11). An installation port (18) is provided on the upper rear left side of the box shell (11). A distance sensor (3) is installed in the left rear hole of the box shell (11). A distance sensor (3) is installed in the left front hole of the box shell (11). A spraying section (5) and a sand-laying module (6) are installed on the upper side of the left and right side seats (15) of the sensor 2 (4). Y-axis linear modules (10) are fixedly connected to the inner side of the mounting groove (16). The sand-laying module (6) includes a support frame (61) installed on the upper side of a pair of Y-axis linear modules (10). The inner side of the middle beam plate of the support frame (61) has a through-hole (62). A shell part (63) is installed on the inner side of the through-hole (62). The shell part (63) includes a sand storage shell (631) fixedly connected to the inner wall of the through-hole (62). A feed hopper (632) is fixedly connected to the upper left side of the sand storage shell (631). A reference block (63) is fixedly connected to the upper side of the feed hopper (632). 3) The lower front and rear inclined surfaces of the sand storage shell (631) are provided with rotating grooves (634), and rotating holes (635) are provided on both the left and right sides of the rotating grooves (634). The lower side of the sand storage shell (631) is provided with a sand inlet (636). Scrapers (637) are fixedly connected to the lower front and rear inclined surfaces of the sand storage shell (631). A sand distribution shell (64) is fixedly connected to the inner side of the sand storage shell (631). An air delivery guide (65) is installed on the outer side of the shell (63). The air delivery guide (65) includes an air pump (651) fixed to the rear side of the sand storage shell (631). The lower end of the air pump (651) is fixedly connected to a diversion pipe (652) that is connected in a continuous manner. The left side of the diversion pipe (652) Both ends of the right side are provided with air shells (653) fixed on the left and right sides of the sand storage shell (631). The inner side of each air shell (653) is provided with an air inlet groove (654) connected to the diversion pipe (652). The lower front and rear sides of the air inlet groove (654) are provided with airflow guides (655). The back side of the front and rear airflow guides (655) is provided with wheel grooves (656). The lower side of each airflow guide (655) is fixedly connected with an air supply pipe (659) that is connected in a continuous manner. A part of an air guide roller (67) is installed in each of the rotating grooves (634). The air guide roller (67) includes a roller shell (671) located inside the rotating groove (634). The inner side of the roller shell (671) is provided with an inner cavity (672).The outer side of the inner cavity (672) is provided with several air guide ports (673) arranged at equal angles. The inner side of each air guide port (673) is fixedly connected to an air filter cover (674). The left and right sides of the roller shell (671) are fixedly connected to shaft tubes (675) that pass through the rotating hole (635) and the air shell (653), and the shaft tubes (675) are all connected to the inner cavity (672). The outer side of each shaft tube (675) is fixedly connected to an impeller (676) located in the wheel groove (656). The inner side of each air guide roller (67) is equipped with a part of an air jet unit (68). The air jet unit (68) includes a central tube (681) located inside the inner cavity (672) and rotatably connected to the inner wall of the shaft tube (675). Several interconnected gas distribution pipes (682) are fixedly connected to the upper side of the 81), and a flow-limiting shell (683) is fixedly connected to the upper end of the gas distribution pipe (682). Both ends of the central pipe (681) are fixedly connected to interconnected sleeves (684), and the sleeves (684) are connected to the upper end of the gas delivery pipe (659). A sand-laying valve (7) is installed on the lower side of the sand-laying module (6). A printing work box (9) located below the sand-laying valve (7) is provided on the upper side of the support bar (17). A premixing part (8) is installed inside the mounting port (18). A control panel (2) is installed on the right side of the front end face of the housing (11). A part of the impeller (676) is located in the airflow guide channel (659). Inside 55), the gas delivery pipe (659) is composed of square connectors on the upper and lower sides and folded pipes between the connectors. The connecting sleeve (684) is a square sleeve structure. The upper square connectors of the gas delivery pipe (659) are all inserted into the inner side of the connecting sleeve (684). The outer curved surface of the air guide roller (67) is in contact with the inner wall of the rotating groove (634). A gap is provided between the front and rear air guide rollers (67). The flow limiting shell (683) is a shell plate structure with an opening on the upper arc surface. The upper arc surface of the flow limiting shell (683) is in contact with the upper curved surface of the inner cavity (672). The lower side of the air inlet groove (654) is provided with a receiving groove (657). The lower side of the receiving groove (657) is provided with a rod path (658). The gas shell (653) The upper part of the drive component (66) is installed on the inner side of the gas shell (653). The drive component (66) includes a base rod (661) that is slidably connected to the rod channel (658). The lower interior of the base rod (661) is provided with a rod groove (664) that is open downwards. The side of the rod groove (664) away from the sand storage shell (631) is provided with a threaded groove (665). The inner side of the threaded groove (665) is threaded with a fastener (666). The inner side of the rod groove (664) is slidably connected with an extension rod (667). The lower end of the extension rod (667) is fixedly connected with a pressure guide block (668) located on the lower side of the gas shell (653). The upper end of the base rod (661) is fixedly connected with a plug block (662) that is slidably connected to the storage groove (657).The upper end of the plug (662) is inserted into the inner side of the air inlet groove (654). A spring (663) is fixedly connected between the lower end face of the plug (662) and the lower inner wall of the storage groove (657). The lower sand valve part (7) includes a base plate (701) fixed to the lower side of the sand storage shell (631). A recess (702) is opened on the upper side of the base plate (701). Track grooves (703) are opened on both the left and right sides of the recess (702). Damping pads (704) are fixedly connected to the upper and lower inner walls of the track grooves (703). A lower valve plate (707) is slidably connected to the front and rear sides of the interior of the recess (702). A valve plate located on the upper side of the lower valve plate (707) is fixedly connected to the front and rear sides of the interior of the recess (702). The upper plate (709) has a low-elasticity baffle (710) fixedly connected to the opposing ends of both the front and rear upper plates (709). The lower ends of the low-elasticity baffles (710) are fixedly connected to the opposing ends of the front and rear lower valve plates (707). Rail rods (705) located inside the rail groove (703) are fixedly connected to both the left and right sides of the lower valve plate (707). Springs (708) are fixedly connected between the opposing sides of the front and rear rail rods (705) and the inner wall of the rail groove (703). A guide block (706) is fixedly connected to the end of each rail rod (705) away from the lower valve plate (707). The upper surface of the guide block (706) that mates with the guide pressure block (668) is an inclined surface, and the inclined surfaces of the two guide blocks (706) form a V-shape.

2. The binder jet sand mold 3D printer according to claim 1, characterized in that: The door drive mechanism (14) consists of an outer shell (141), a motor (142), gears (143), and racks (144). The outer shell (141) is fixed to the front side of the housing (11). Motors (142) are fixedly connected to both sides of the inner side of the outer shell (141). Gears (143) are fixedly connected to the end of the output shaft of each motor (142). Racks (144) are meshed with the rear side of each gear (143), and racks (144) are fixed to the front side of the door (13). The width of the door (13) is larger than the printing width. The width of the working box (9) is such that distance sensor 1 (3) and distance sensor 2 (4) are set at the same height as the reference block (633). Distance sensor 1 (3) is located on the left side of the sand pipe of the premixing section (8). The feed hopper (632) is aligned with the premixing section (8). The sand separating shell (64) is composed of an inclined guide shell and several sand separating pipes set at an inclined angle on the front side of the inclined guide shell. The inclined guide shell of the sand separating shell (64) has an inclined guide groove that is inclined forward on the inner side of the inclined guide shell. The sand separating shell (64) is set on the lower side of the feed hopper (632).

3. The binder jet sand mold 3D printer according to claim 1, characterized in that: The upper and lower end faces of the rail rod (705) are in contact with the opposing surfaces of the upper and lower damping pads (704). The guide blocks (706) are all located on the lower side of the pressure guide block (668). There is a gap between the upper end of the extension rod (667) and the upper inner wall of the rod groove (664). The fastener (666) consists of a bolt and a damping block. The damping block of the fastener (666) is in contact with the outer end face of the extension rod (667). The surface of the extension rod (667) is marked with a scale. The spacing between the front and rear upper connecting plates (709) is the same as the width of the lower sand opening (636). The upper connecting plates (709) are all located on the front and rear sides of the bottom of the lower sand opening (636). The low elasticity baffle (710) is located directly below the lower sand opening (636). The lowest point of the scraper (637) is lower than the lowest point of the lower sand valve (7).

Images