A sand mold 3D printer

Abstract

The present invention relates to the technical field of casting modeling. A sand mold 3D printer includes a box body. A workbench is arranged inside the box body, and a moving avoidance mechanism is arranged on the top of the box body. Cleaning and material collecting mechanisms for cleaning the print head are arranged on both the front and back sides of the workbench. In the present invention, the sand spreading device and the print head respectively use two independent and perpendicular driving parts as power. After the sand spreading device spreads sand unidirectionally, the print head prints continuously from front to back. After printing, the print head moves to the position of the cleaning and material collecting mechanism at the rear for avoidance. Subsequently, the sand spreading device spreads sand in the reverse direction, and the print head performs reverse continuous printing from back to front, realizing bidirectional sand spreading and bidirectional printing. There is no idle stroke for both the sand spreading device and the print head, and the printing efficiency is high. When the print head performs avoidance, the pressure driving assembly drives the automatic cleaning assembly to scrape and clean the residual glue and grit at the bottom of the print head. The cleaning of the bottom of the scraper is realized through the cleaning mechanism.

Description

Technical Field

[0001] The present invention belongs to the technical field of casting molding, and particularly relates to a sand mold 3D printer. Background Art

[0002] A sand mold 3D printer is a device for sand molds in the casting process. This type of 3D printing utilizes a technology called binder jetting. By selectively depositing a liquid binder onto a layer of sand, the required sand mold is constructed layer by layer. Sand mold 3D printers are mainly used in fields such as automobile manufacturing, aerospace, and mechanical engineering.

[0003] 1. In existing sand mold 3D printers, the print head and the sand spreading mechanism usually share a track for movement. After the sand spreading mechanism spreads a layer of fine sand along the track, the sand spreading mechanism needs to move along the track to the initial position for avoidance. At this time, the print head prints along the track. After printing is completed, the print head also needs to return to the initial position along the track for avoidance, and the above-mentioned sand spreading operation is repeated to complete the sand mold 3D printing. However, in this printing method, both the sand spreading mechanism and the print head have a section of idle travel, reducing the printing efficiency.

[0004] 2. After sand spreading in existing sand mold 3D printers, the laid sand layer is usually leveled by a scraper. Since the foundry sand used for printing is usually preliminarily mixed with a gel before laying and then spread, the foundry sand itself has a certain viscosity. Therefore, when the scraper levels, local adhesion of sand grains is likely to occur, affecting the effect of the next leveling and easily causing local unevenness during the next leveling. Therefore, the bottom of the scraper needs to be cleaned. The existing cleaning method usually uses a brush for cleaning. However, in the case of long-term use, sand grains are likely to adhere to the brush, and the sand grains on the brush will affect the cleaning of the scraper. Summary of the Invention

[0005] The purpose of the present invention is to provide a sand mold 3D printer with a simple structure and reasonable design to solve the above problems.

[0006] The present invention achieves the above purpose through the following technical solutions:

[0007] A sand mold 3D printer includes a box body. A workbench is arranged inside the box body. A moving avoidance mechanism is arranged on the top of the box body. Cleaning and material collecting mechanisms are arranged on both the front and rear sides of the workbench. Two limiting grooves are symmetrically opened on the front and rear sides of the workbench. And a second electric slide rail is fixedly arranged below the limiting grooves at the bottom of the workbench. Two connecting rods are slidably installed on both second electric slide rails through second electric sliders. Two first installation grooves and two sand leakage grooves are symmetrically opened on the left and right sides of the top of the workbench. A cleaning mechanism is jointly arranged inside the first installation grooves and on the second electric slide rails.

[0008] The moving avoidance mechanism includes two side plates symmetrically and fixedly connected to both sides of the top of the box body. A lead screw is rotatably connected between the two side plates. A servo motor is fixedly installed on the right side plate, and the output end of the servo motor is fixedly connected to the right end of the lead screw. A movable block is threadedly connected to the lead screw through a ball nut. A third electric slide rail is fixedly installed at the bottom of the movable block. The bottom of the third electric slide rail is slidably connected to a print head through a third electric slider. The frontmost and rearmost ends of the third electric slide rail are the avoidance positions of the print head for the sand spreading device. A limiting plate is fixedly installed at the top of the movable block, and a second guiding rod slidably penetrates through the middle of the limiting plate. The second guiding rod is arranged between the two side plates.

[0009] Preferably, a feeding hopper is arranged on the right side of the top of the box body. The feeding hopper is connected to the sand mixing box through a pipeline. A second installation groove is opened at the center of the top of the workbench. A sand spreading device is arranged at the top of the two connecting rods. Two fixing arms are symmetrically and fixedly installed on both the front and rear sides of the left and right sides of the sand spreading device. A first top plate is fixedly connected to the bottoms of the two fixing arms. A scraper is fixedly installed at the bottom of the first top plate.

[0010] Preferably, a through hole penetrating through the front and rear is opened in the lower part of the box body. Two first electric slide rails are symmetrically arranged on the left and right below the box body. A lifting sand box is slidably connected to the tops of the two first electric slide rails through a first electric slider. There are two lifting sand boxes. The lifting sand box includes a bottom plate fixedly connected to the top of the first electric slider. Four corners of the top of the bottom plate are respectively fixedly installed with first hydraulic cylinders. A sand box body is arranged at the top of the multiple first hydraulic cylinders. A second hydraulic cylinder is fixedly installed at the center of the inner bottom surface of the sand box body. The output end of the second hydraulic cylinder is fixedly installed with a lifting plate. The lifting plate is slidably connected to the inside of the sand box body in a sealed manner.

[0011] Preferably, the cleaning and material collecting mechanism includes an emptying box fixedly installed on the workbench. A collecting hopper is fixedly installed on the side of the bottom of the emptying box away from the workbench. The collecting hopper is communicated with the inside of the emptying box. A driving component is arranged on the side of the emptying box away from the workbench. An automatic cleaning component is arranged between the driving component and the emptying box. First fixing rods are fixedly installed at the bottoms of both the front and rear sides of the print head.

[0012] Preferably, the driving assembly includes two fixing brackets symmetrically and fixedly connected to the side of the clearance box away from the workbench. An installation shaft is rotatably connected between the two fixing brackets. A first gear is fixedly sleeved in the middle of the installation shaft. The tops of the two fixing brackets are fixedly connected to a second top plate. A first limit slider is fixedly installed at the center of the bottom of the second top plate. The bottom of the first limit slider is slidably connected to a first limit slide rail. A second rack meshing with the top of the first gear is fixedly installed at the bottom of the first limit slide rail. A stop block is fixedly installed on the side of the first limit slide rail away from the clearance box. An activity insertion plate slidably penetrates through the middle of the side of the clearance box away from the workbench. A first rack meshing with the bottom of the first gear is fixedly installed on the side of the activity insertion plate away from the workbench. An automatic cleaning assembly is arranged at the other end of the activity insertion plate.

[0013] Preferably, the automatic cleaning assembly includes a supporting plate fixedly connected to the other end of the activity insertion plate. A cleaning scraper is fixedly arranged on the top of the supporting plate. A first guiding rod slidably penetrates through both the left and right sides of the supporting plate. The first guiding rod is arranged inside the clearance box. A first spring is sleeved on the first guiding rod. The first spring is arranged between the supporting plate and the inner wall of the clearance box. Two gantry frames are symmetrically and fixedly installed on the left and right sides of the top of the clearance box away from the workbench. A conical cleaning plate for cleaning the top of the cleaning scraper is fixedly installed on the top inner walls of the two gantry frames.

[0014] Preferably, a collection box is arranged below the two sand leakage grooves. Blocking covers are fixedly installed on the sides of the tops of the two first installation grooves away from the center of the workbench. Support legs are fixedly installed at the four corners of the bottom of the workbench.

[0015] Preferably, the cleaning mechanism includes two brush rollers rotatably connected inside the first installation groove for cleaning the bottom of the scraper. Second gears are fixedly sleeved on the front ends of the two brush rollers.

[0016] Preferably, a fixed shaft is rotatably connected to the front side wall inside the first installation groove. A third gear meshing with the two second gears is fixedly sleeved on the fixed shaft.

[0017] Preferably, second limit slide rails are fixedly installed on the sides of the two second electric slide rails close to each other. Second limit sliders are slidably connected to the two second limit slide rails. The second limit sliders and the second electric sliders on the second electric slide rails are connected by connecting arms. A third rack meshing with the bottom of the third gear is fixedly installed on the connecting arm at the front side.

[0018] The beneficial effects of the present invention are as follows:

[0019] 1. The paving sand device and the printing head of the present invention respectively use two independent and perpendicular driving parts as power. After the paving sand device paves sand unidirectionally, the printing head prints. After printing, the printing head moves to the position of the cleaning and material collecting mechanism for avoidance. Then the paving sand device paves sand in the reverse direction, and the printing head prints in the reverse direction, realizing bidirectional sand paving and bidirectional printing. There is no idle stroke for both the paving sand device and the printing head, improving the printing efficiency.

[0020] 2. When the printing head enters the area of the cleaning and material collecting mechanism for clearance, the first fixed rod on the printing head squeezes the driving component, driving the cleaning scraper in the automatic cleaning component to scrape and clean the residual glue and grit at the bottom of the printing head. And after the scraping and cleaning, as the printing head leaves, the cleaning scraper resets. During the reset process, the conical cleaning plate scrapes and cleans the top of the cleaning scraper. The impurities on the conical cleaning plate fall into the collecting hopper by gravity, realizing the cleaning of the bottom of the printing head and the automatic cleaning of the cleaning scraper itself, avoiding the situation that the cleaning efficiency decreases due to excessive impurities remaining on the cleaning scraper.

[0021] 3. When the paving sand device of the present invention retreats from the working area to the left and right sides driven by the second electric slide rail, the second electric slide rail synchronously drives the third rack to retreat. Through the meshing of the third rack and the third gear, it indirectly drives the brush roller to rotate towards the direction of the blocking cover. Through the rotation of the brush roller, the bottom of the scraper is cleaned. At the same time, when the brush roller rotates, the impurities remaining on the brush roller are centrifugally thrown out, avoiding the problem that the cleaning effect decreases due to the accumulation of impurities on the brush roller. And the air flow generated by the rotation of the brush roller further blows and cleans the bottom of the scraper. Description of the Drawings

[0022] Figure 1 is the three-dimensional view of the overall structure of the present invention;

[0023] Figure 2 is the partial cross-sectional view of the overall structure of the present invention;

[0024] Figure 3 is the partial cross-sectional view of the lifting sand box of the present invention;

[0025] Figure 4 is the three-dimensional view of the moving avoidance mechanism, workbench, cleaning and material collecting mechanism and cleaning mechanism of the present invention;

[0026] Figure 5 is the partial cross-sectional view of the cleaning and material collecting mechanism of the present invention;

[0027] Figure 6 is of the present invention Figure 5 enlarged schematic view of area A in;

[0028] Figure 7 is the partial cross-sectional three-dimensional view of the cleaning mechanism and the workbench of the present invention;

[0029] Figure 8 is of the present invention Figure 7 Schematic enlarged view of area B in the present invention;

[0030] Figure 9 is the front cross-sectional view of the cleaning mechanism and the workbench of the present invention.

[0031] In the figure: 1, box body; 2, feeding hopper; 3, first electric slide rail; 4, lifting sand box; 41, bottom plate; 42, sand box body; 43, first hydraulic cylinder; 44, lifting plate; 45, second hydraulic cylinder; 5, cleaning and collecting mechanism; 51, driving assembly; 511, first rack; 512, mounting shaft; 513, first gear; 514, fixed frame; 515, first limiting slide rail; 516, second rack; 517, second top plate; 518, first limiting slider; 519, movable insertion plate; 52, collecting hopper; 53, automatic cleaning assembly; 531, first spring; 532, first guide rod; 533, gantry; 534, cleaning scraper; 535, supporting plate; 536, conical cleaning plate; 54, first fixed rod; 55, clearance box; 6, moving and avoiding mechanism; 61, side plate; 62, second guide rod; 63, lead screw; 64, movable block; 65, limiting plate; 66, third electric slide rail; 67, servo motor; 7, cleaning mechanism; 71, brush roller; 72, second gear; 73, third gear; 74, third rack; 75, second limiting slide rail; 76, fixed shaft; 77, second limiting slider; 78, connecting arm; 8, blocking cover; 9, limiting groove; 10, second electric slide rail; 11, first installation groove; 12, sand spreading device; 13, workbench; 14, second installation groove; 15, printing head; 16, fixed arm; 17, scraper; 18, first top plate; 19, connecting rod; 20, sand leakage groove. Detailed implementation manners

[0032] The following further describes the present application in detail with reference to the drawings. It is necessary to point out here that the following specific implementation manners are only used to further illustrate the present application and cannot be understood as limiting the protection scope of the present application. Those skilled in the art can make some non-essential improvements and adjustments to the present application according to the above application content.

[0033] Embodiment: Please refer to Figure 1 , Figure 2 and Figure 4, A sand mold 3D printer, comprising a box body 1, a workbench 13 is arranged inside the box body 1, a moving avoidance mechanism 6 is arranged at the top of the box body 1, cleaning and material collecting mechanisms 5 for cleaning the print head 15 are arranged on both the front and rear sides of the workbench 13, the two cleaning and material collecting mechanisms 5 are centrally symmetrically distributed around the center of the workbench 13, two limiting grooves 9 are symmetrically arranged front and rear on the workbench 13, and a second electric slide rail 10 is fixedly arranged at the bottom of the workbench 13 below the limiting grooves 9. Two connecting rods 19 are slidably installed on the two second electric slide rails 10 through second electric sliders. A sand spreading device 12 is jointly arranged at the tops of the two connecting rods 19. Two fixing arms 16 are symmetrically fixed in the front and rear directions on both the left and right sides of the sand spreading device 12. A first top plate 18 is jointly fixed at the bottoms of the two fixing arms 16. A scraping plate 17 is fixedly arranged at the bottom of the first top plate 18. An adjusting screw (not shown in the figure) is installed on the first top plate 18 to facilitate adjusting the position of the scraping plate 17 according to the usage situation. Two first installation grooves 11 and two sand leakage grooves 20 are symmetrically arranged left and right on the top of the workbench 13. A cleaning mechanism 7 is jointly arranged inside the first installation grooves 11 and on the second electric slide rails 10. A feeding hopper 2 is arranged on the right side at the top of the box body 1. The feeding hopper 2 is connected to a sand mixing box (not shown in the figure) through a pipeline. A second installation groove 14 is opened at the center of the top of the workbench 13. A collection box is arranged below the two sand leakage grooves 20. A blocking cover 8 is fixedly installed on one side away from the center of the workbench 13 at the top of the two first installation grooves 11. Support legs are respectively fixedly installed at the four corners of the bottom of the workbench 13.

[0034] During the use of the present invention, the sand mixing box and the feeding hopper 2 are used to convey the mixed sand and gravel to the sand spreading device 12. The sand spreading device 12 is used to evenly spread the sand and gravel onto the printing area. The sand spreading device 12 can spread sand in both directions and can also level in both directions. The scraping plate 17 is used to level the laid sand and gravel. The cleaning mechanism 7 is used to brush and clean the bottom of the scraping plate 17. The cleaning and material collecting mechanism 5 is used to clean the print head 15 and automatically collect impurities.

[0035] Please refer to Figure 2 , Figure 3 and Figure 4 , a through hole penetrating through the front and rear is opened at the lower part of the box body 1, and two first electric slide rails 3 are symmetrically arranged on the left and right below the box body 1. A lifting sand box 4 is jointly slidably connected to the tops of the two first electric slide rails 3 through first electric sliders. There are two lifting sand boxes 4, and both are slidably connected to the first electric slide rails 3. The lifting sand box 4 includes a bottom plate 41 fixedly connected to the top of the first electric slider. First hydraulic cylinders 43 are respectively fixedly installed at the four corners of the top of the bottom plate 41. A sand box body 42 is jointly arranged at the tops of the plurality of first hydraulic cylinders 43. A second hydraulic cylinder 45 is fixedly installed at the center of the inner bottom surface of the sand box body 42. A lifting plate 44 is fixedly installed at the top of the output end of the second hydraulic cylinder 45. The lifting plate 44 is hermetically slidably connected inside the sand box body 42.

[0036] During use, start the first electric slide rail 3. The first electric slide rail 3 is conveyed to directly below the second installation groove 14 through the first electric slider. At this time, start the first hydraulic cylinder 43. The output end of the first hydraulic cylinder 43 extends, driving the sand box body 42 and the second hydraulic cylinder 45 thereon to move upward until the upper edge of the sand box body 42 is flush with the top of the second installation groove 14. At this time, start the second hydraulic cylinder 45. The output end of the second hydraulic cylinder 45 extends, driving the lifting plate 44 to move upward. The distance between the lifting plate 44 and the top edge of the sand box body 42 is the thickness of the laid gravel. Each time gravel is laid, the output end of the second hydraulic cylinder 45 descends a certain distance, and the descending distance is the thickness of the laid gravel. The moving avoidance mechanism 6 and the second electric slide rail 10 are vertically distributed at a right angle. The sand spreader 12 moves through the second electric slide rail 10, and the print head 15 is driven by the moving avoidance mechanism 6. The front and rear ends of the moving avoidance mechanism 6 are avoidance positions, that is, when the print head 15 moves to the avoidance position, the sand spreader 12 can smoothly slide along the second electric slide rail 10, and there will be no interference between the print head 15 and the sand spreader 12. Thus, neither the print head 15 nor the sand spreader 12 has an idle stroke, improving the printing efficiency.

[0037] Please refer to Figure 2 and Figure 4 As shown in, the moving avoidance mechanism 6 includes two side plates 61 fixedly connected to both sides of the top of the box body 1 symmetrically from left to right. A lead screw 63 is rotatably connected between the two side plates 61. A servo motor 67 is fixedly installed on the right side plate 61. The output end of the servo motor 67 is fixedly connected to the right end of the lead screw 63. A movable block 64 is threadedly connected to the lead screw 63 through a ball nut. A third electric slide rail 66 is fixedly installed at the bottom of the movable block 64. The bottom of the third electric slide rail 66 is slidably connected to the print head 15 through a third electric slider. The frontmost and rearmost ends of the third electric slide rail 66 are the avoidance positions of the print head 15 with respect to the sand spreader 12. A limiting plate 65 is fixedly installed at the top of the movable block 64. A second guide rod 62 slidably penetrates through the middle of the limiting plate 65. The second guide rod 62 is arranged between the two side plates 61.

[0038] During use, first start the servo motor 67. The output end of the servo motor 67 drives the lead screw 63 to rotate, synchronously driving the movable block 64 and the third electric slide rail 66 thereon to slide left and right along the direction of the second guide rod 62. At the same time, the third electric slide rail 66 and the third electric slider thereon drive the print head 15 to slide back and forth. The combined use of the two realizes the movement of the print head 15. Before sand spreading, the moving avoidance mechanism 6 moves the print head 15 to the top of the cleaning and material collecting mechanism 5 located at the front side, realizing the avoidance of the print head 15 from the sand spreader 12. At this time, the sand spreader 12 is driven by the second electric slide rail 10 to move from right to left. The sand spreader 12 stores fine sand inside. When the sand spreader 12 moves to the right side of the top of the lifting plate 44, it starts to spread sand, and stops spreading sand when it moves to the left side of the lifting plate 44, realizing the uniform spreading of the fine sand required for printing on the top of the lifting plate 44. During spreading, the scraper 17 levels the sand and gravel. When spreading sand from right to left, the right scraper 17 is used for leveling. And when scraping from right to left, the excess fine sand is scraped into the sand leakage groove 20 and falls into the collection box through the sand leakage groove 20 for collection, reducing the amount of fine sand entering the cleaning mechanism 7. At this time, the moving avoidance mechanism 6 drives the print head 15 to move continuously back and forth, and coats the curing agent on the specified area of the sand and gravel according to the designed shape. After one layer of printing is completed, the moving avoidance mechanism 6 moves the print head 15 to the top of the cleaning and material collecting mechanism 5 at the rear side for avoidance. At this time, the sand spreader 12 spreads sand from left to back, and then the print head 15 prints continuously from back to front. By applying glue layer by layer and spreading sand layer by layer according to the designed shape, the printing is completed, realizing two-way sand spreading and two-way printing. There is no idle stroke for both the print head 15 and the sand spreader 12, improving the printing efficiency. When the sand spreader 12 reciprocates one cycle and returns to the right side, the sand spreader 12 is refilled with sand using the feeding hopper 2.

[0039] Please refer to Figure 4 and Figure 5 As shown in FIGS. 5 and 6, the cleaning and material collecting mechanism 5 includes an emptying box 55 fixedly installed on the workbench 13. A collecting hopper 52 is fixedly provided on one side of the bottom of the emptying box 55 away from the workbench 13. The collecting hopper 52 is internally communicated with the emptying box 55. A driving assembly 51 is arranged on one side of the emptying box 55 away from the workbench 13, and an automatic cleaning assembly 53 is jointly arranged between the driving assembly 51 and the emptying box 55. Fixed rods 54 are fixedly installed at the bottoms of the front and rear sides of the print head 15.

[0040] Please refer to Figure 4 and Figure 5, the driving assembly 51 includes two fixing brackets 514 symmetrically and fixedly connected to the side of the clearance box 55 away from the workbench 13. An installation shaft 512 is rotatably connected between the two fixing brackets 514. A first gear 513 is fixedly sleeved in the middle of the installation shaft 512. The tops of the two fixing brackets 514 are fixedly connected to a second top plate 517. A first limit slider 518 is fixedly installed at the center of the bottom of the second top plate 517. The bottom of the first limit slider 518 is slidably connected to a first limit slide rail 515. A second rack 516 meshing with the top of the first gear 513 is fixedly installed at the bottom of the first limit slide rail 515. A stop block is fixedly installed on the side of the first limit slide rail 515 away from the clearance box 55. An activity insertion plate 519 slidably penetrates through the middle of the side of the clearance box 55 away from the workbench 13. A first rack 511 meshing with the bottom of the first gear 513 is fixedly installed on the side of the activity insertion plate 519 away from the workbench 13. The other end of the activity insertion plate 519 is provided with an automatic cleaning assembly 53.

[0041] Please refer to Figure 4 , Figure 5 and Figure 6 , the automatic cleaning assembly 53 includes a supporting plate 535 fixedly connected to the other end of the activity insertion plate 519. A cleaning scraper 534 is fixedly arranged on the top of the supporting plate 535. A first guiding rod 532 slidably penetrates through both the left and right sides of the supporting plate 535. The first guiding rod 532 is arranged inside the clearance box 55. A first spring 531 is sleeved on the first guiding rod 532. The first spring 531 is arranged between the supporting plate 535 and the inner wall of the clearance box 55. Two gantry frames 533 are symmetrically and fixedly installed on the left and right sides of the top of the clearance box 55 away from the workbench 13. And a conical cleaning plate 536 for cleaning the top of the cleaning scraper 534 is fixedly installed at the top of the inner walls of the two gantry frames 533.

[0042] During use, when the moving avoidance mechanism 6 drives the print head 15 to move to the avoidance position, at this time, the first fixed rod 54 on the print head 15 presses the second rack 516, driving the second rack 516 to move away from the workbench 13, indirectly driving the first rack 511 and the movable insertion plate 519 thereon to move towards the workbench 13, and at the same time driving the supporting plate 535 and the cleaning scraper 534 thereon to move towards the workbench 13, synchronously compressing the first spring 531. The cleaning scraper 534 is used to clean and scrape sundries such as grit and glue at the bottom of the print head 15, realizing the automatic cleaning of the print head 15 without manual participation, saving time and effort. And when the print head 15 leaves, at this time, under the restoring force of the first spring 531, the supporting plate 535 and the cleaning scraper 534 thereon are driven to move back away from the workbench 13. During the backward movement, the cleaning scraper 534 passes under the conical cleaning plate 536, and the conical cleaning plate 536 is used to clean the top of the cleaning scraper 534, cleaning the impurities remaining on the cleaning scraper 534 to prevent affecting the next cleaning. The impurities on the conical cleaning plate 536 fall into the collection hopper 52 under the extrusion of the cleaning scraper 534 and its own gravity, realizing the automatic cleaning of the print head 15 and the self-cleaning of the cleaning scraper 534.

[0043] Please refer to Figure 4 、 Figure 7 、 Figure 8 and Figure 9 Figure, the cleaning mechanism 7 includes two brush rollers 71 rotatably connected inside the first installation groove 11 for cleaning the bottom of the scraper 17. At the front ends of the two brush rollers 71, second gears 72 are fixedly sleeved. A fixed shaft 76 is rotatably connected to the front side wall inside the first installation groove 11, and a third gear 73 that meshes with the two second gears 72 is fixedly sleeved on the fixed shaft 76.

[0044] Please refer to Figure 2 、 Figure 7 、 Figure 8 and Figure 9 Figure, on one side where the two second electric slide rails 10 are close to each other, second limit slide rails 75 are fixedly installed. Second limit sliders 77 are slidably connected to the two second limit slide rails 75. The second limit sliders 77 are connected to the second electric sliders on the second electric slide rails 10 through connecting arms 78. A third rack 74 that meshes with the bottom of the third gear 73 is fixedly installed on the connecting arm 78 located at the front side.

[0045] During use, when the second electric slide rail 10 drives the sand spreading device 12 to spread sand along the limit groove 9 from right to left or from left to right, it simultaneously drives the fixed arm 16 and the first top plate 18 thereon to slide, and at the same time drives the scraper 17 to level the fine sand. As the second electric slide rail 10 drives the second electric slider and the connecting arm 78 thereon to continue moving, it simultaneously drives the second limit slider 77 and the third rack 74 thereon to move, and then drives the third gear 73 to rotate. The tooth ratio of the third gear 73 to the second gear 72 is six to one, driving the second gear 72 and the brush roller 71 thereon to rotate at high speed. As the brush roller 71 rotates, it brushes and cleans the bottom of the scraper 17. During the rotary cleaning, the residual grit on the brush roller 71 is thrown out by centrifugal force, and the blocking cover 8 blocks the thrown-out grit, reducing the residue on the brush roller 71 and avoiding the influence of the residual fine sand on the brush roller 71 on the cleaning effect of the scraper 17. Moreover, the wind force generated when the brush roller 71 rotates realizes further cleaning of the bottom of the scraper 17.

[0046] It should be noted that for this sand mold 3D printer, during use, first start the first electric slide rail 3. The first electric slide rail 3 transports the lifting sand box 4 to directly below the second installation groove 14 through the first electric slider. At this time, start the first hydraulic cylinder 43. The output end of the first hydraulic cylinder 43 extends, driving the sand box body 42 and the second hydraulic cylinder 45 thereon to move upward until the upper edge of the sand box body 42 is flush with the top of the second installation groove 14. At this time, start the second hydraulic cylinder 45. The output end of the second hydraulic cylinder 45 extends, driving the lifting plate 44 to move upward. The distance between the lifting plate 44 and the top edge of the sand box body 42 is the thickness of the laid gravel. Before sand laying, the moving avoidance mechanism 6 moves the print head 15 to the top of the cleaning and material collecting mechanism 5 located on the front side. At this time, drive the sand laying device 12 to move from right to left through the second electric slide rail 10 until the gravel is evenly laid on the top of the lifting plate 44. While laying, the scraper 17 levels the gravel. At this time, use the moving avoidance mechanism 6 to drive the print head 15 to move continuously back and forth, and apply the curing agent to the specified area of the gravel according to the designed shape. After one layer of printing is completed, the moving avoidance mechanism 6 moves the print head 15 to the top of the cleaning and material collecting mechanism 5 located on the rear side for avoidance. At this time, the sand laying device 12 lays sand from left to back, and then the print head 15 prints continuously from back to front, realizing two-way sand laying and two-way printing. There is no idle stroke for both the print head 15 and the sand laying device 12, improving the printing efficiency. After printing is completed, use the first electric slide rail 3 to move the printed lifting sand box 4 out of the working area and move a new lifting sand box 4 to the working area, realizing the alternating work of the double lifting sand boxes 4, with high working efficiency. When the print head 15 is avoiding, the cleaning and material collecting mechanism 5 automatically cleans the print head 15 and automatically collects impurities, without manual participation, saving time and effort. When the sand laying device 12 is laying sand, the cleaning mechanism 7 brushes the bottom of the scraper 17 for cleaning, and the cleaning mechanism 7 is linked with the second electric slide rail 10. The rotating cleaning action of the cleaning mechanism 7 does not require an additional drive source, and the centrifugal force of rotation realizes the self-cleaning of the cleaning mechanism 7 itself.

[0047] The above embodiments only illustrate several implementation manners of the present invention. The description is relatively specific and detailed, but it should not be construed as a limitation on the scope of the present invention patent. It should be pointed out that for those of ordinary skill in the art, without departing from the concept of the present invention, several deformations and improvements can still be made, and these all belong to the protection scope of the present invention.

Claims

1. A sand mold 3D printer, comprising a box body (1), characterized in that: Inside the box body (1), a workbench (13) is provided. A moving avoidance mechanism (6) is provided at the top of the box body (1). Cleaning and material collecting mechanisms (5) are provided on both the front and rear sides of the workbench (13). Two limiting grooves (9) are symmetrically formed on the front and rear of the workbench (13). And a second electric slide rail (10) is fixedly installed below the limiting grooves (9) at the bottom of the workbench (13). Two connecting rods (19) are slidably installed on the two second electric slide rails (10) through second electric sliders. Two first installation grooves (11) and two sand leakage grooves (20) are symmetrically formed on the left and right of the top of the workbench (13). A cleaning mechanism (7) is jointly provided inside the first installation groove (11) and on the second electric slide rail (10); The moving avoidance mechanism (6) includes two side plates (61) symmetrically and fixedly connected to both sides of the top of the box body (1). A lead screw (63) is rotatably connected between the two side plates (61). A servo motor (67) is fixedly installed on the side plate (61) on the right side. The output end of the servo motor (67) is fixedly connected to the right end of the lead screw (63). A movable block (64) is threadedly connected to the lead screw (63) through a ball nut. A third electric slide rail (66) is fixedly installed at the bottom of the movable block (64). A print head (15) is slidably connected to the bottom of the third electric slide rail (66) through a third electric slider. And the frontmost and rearmost ends of the third electric slide rail (66) are the avoidance positions of the print head (15) for the sand spreading device (12). A limiting plate (65) is fixedly installed at the top of the movable block (64). A second guiding rod (62) slidably penetrates through the middle of the limiting plate (65). The second guiding rod (62) is arranged between the two side plates (61); The cleaning and material collecting mechanism (5) includes an emptying box (55) fixedly installed on the workbench (13). A collecting hopper (52) is fixedly installed on one side of the bottom of the emptying box (55) away from the workbench (13). The collecting hopper (52) is communicated with the inside of the emptying box (55). A driving component (51) is arranged on one side of the emptying box (55) away from the workbench (13). And an automatic cleaning component (53) is jointly provided between the driving component (51) and the emptying box (55). First fixing rods (54) are fixedly installed at the bottom of both the front and rear sides of the print head (15); The driving component (51) includes two fixing brackets (514) symmetrically and fixedly connected to the side of the clearance box (55) away from the workbench (13). An installation shaft (512) is rotatably connected between the two fixing brackets (514). A first gear (513) is fixedly sleeved in the middle of the installation shaft (512). A second top plate (517) is fixedly connected to the tops of the two fixing brackets (514). A first limit slider (518) is fixedly installed at the center of the bottom of the second top plate (517). The bottom of the first limit slider (518) is slidably connected to a first limit slide rail (515). A second rack (516) meshing with the top of the first gear (513) is fixedly installed at the bottom of the first limit slide rail (515). A stop block is fixedly installed on the side of the first limit slide rail (515) away from the clearance box (55). An activity insertion plate (519) slidably penetrates through the middle of the side of the clearance box (55) away from the workbench (13). A first rack (511) meshing with the bottom of the first gear (513) is fixedly installed on the side of the activity insertion plate (519) away from the workbench (13). An automatic cleaning component (53) is arranged at the other end of the activity insertion plate (519).

2. The sand mold 3D printer according to claim 1, wherein: A feeding hopper (2) is arranged on the right side of the top of the box body (1). The feeding hopper (2) is connected to the sand mixing box through a pipeline. A second installation groove (14) is opened at the center of the top of the workbench (13). A sand spreading device (12) is arranged at the tops of the two connecting rods (19). Two fixing arms (16) are symmetrically and fixedly installed on the front and back sides of the left and right sides of the sand spreading device (12). A first top plate (18) is fixedly connected to the bottoms of the two fixing arms (16). A scraping plate (17) is fixedly arranged at the bottom of the first top plate (18).

3. The sand mold 3D printer according to claim 1, characterized in that: A through hole penetrating through the front and back is opened in the lower part of the box body (1). And two first electric slide rails (3) are symmetrically arranged on the left and right sides below the box body (1). A lifting sand box (4) is slidably connected to the tops of the two first electric slide rails (3) through a first electric slider. There are two lifting sand boxes (4). The lifting sand box (4) includes a bottom plate (41) fixedly connected to the top of the first electric slider. First hydraulic cylinders (43) are respectively fixedly installed at the four corners of the top of the bottom plate (41). A sand box body (42) is arranged at the tops of the plurality of first hydraulic cylinders (43). A second hydraulic cylinder (45) is fixedly installed at the center of the inner bottom surface of the sand box body (42). A lifting plate (44) is fixedly installed at the top of the output end of the second hydraulic cylinder (45). The lifting plate (44) is slidably and sealingly connected inside the sand box body (42).

4. A sand mold 3D printer according to claim 1, characterized in that: The automatic cleaning assembly (53) includes a support plate (535) fixedly connected to the other end of the movable plug board (519). A cleaning scraper (534) is fixedly arranged on the top of the support plate (535). One guide rod (532) is slidably penetrated through both the left and right sides of the support plate (535). The one guide rod (532) is arranged inside the clearance box (55). A first spring (531) is sleeved on the one guide rod (532). The first spring (531) is arranged between the support plate (535) and the inner wall of the clearance box (55). On the side of the top of the clearance box (55) far from the workbench (13), two gantry frames (533) are symmetrically and fixedly installed on the left and right. And a conical cleaning plate (536) for cleaning the top of the cleaning scraper (534) is fixedly installed on the top of the inner walls of the two gantry frames (533).

5. The sand mold 3D printer according to claim 1, characterized in that: A collection box is arranged below the two sand leakage grooves (20). On the side of the top of the two first installation grooves (11) far from the center of the workbench (13), a blocking cover (8) is fixedly installed. Support legs are respectively fixedly installed at the four corners of the bottom of the workbench (13).

6. The sand mold 3D printer according to claim 1, characterized in that: The cleaning mechanism (7) includes two brush rollers (71) rotatably connected inside the first installation groove (11) for cleaning the bottom of the scraper (17). A second gear (72) is fixedly sleeved on the front end of each of the two brush rollers (71).

7. The sand mold 3D printer according to claim 6, characterized in that: A fixed shaft (76) is rotatably connected to the front side wall inside the first installation groove (11). A third gear (73) meshing with the two second gears (72) is fixedly sleeved on the fixed shaft (76).

8. The sand mold 3D printer according to claim 6, wherein: On the side of the two second electric slide rails (10) close to each other, a second limit slide rail (75) is fixedly installed. A second limit slider (77) is slidably connected to each of the two second limit slide rails (75). The second limit slider (77) is connected to the second electric slider on the second electric slide rail (10) through a connecting arm (78). A third rack (74) meshing with the bottom of the third gear (73) is fixedly installed on the connecting arm (78) located at the front side.

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