A digitalized casting lost foam molding device

Abstract

The application relates to the technical field of foundry molding, in particular to a digital foundry lost foam molding device, which comprises a vibrating table and a sand box body arranged on the top of the vibrating table, the inside of the sand box body is provided with a fixed bottom plate, the bottom of the fixed bottom plate is provided with a slidable lifting box, a plurality of positioning rods are elastically arranged in the inside of the lifting box, the top surface of the fixed bottom plate is provided with first through holes for the positioning rods to pass through, the rod wall of the positioning rod is in sliding fit with the inner wall of the first through hole, and the top end of the positioning rod is provided with a top end arc. The white mold bottom with an irregular shape is profiled in fit with the positioning rod array, the stability of the white mold with an irregular shape is guaranteed, compared with the traditional manual sand fixing mode, the defects caused by the white mold inclination, such as cold separation and insufficient pouring, are fundamentally eliminated, and the equipment adaptability and production efficiency are remarkably improved.

Description

Technical Field

[0001] This invention relates to the field of casting molding technology, specifically to a lost foam molding device based on digital casting. Background Technology

[0002] Lost foam casting (also known as solid foam casting) is a representative process of green casting in the 21st century. Its core lies in replacing traditional metal or wooden molds with foam plastic models. The white model is digitally prepared through 3D scanning, topology optimization, and CNC machining. Then, the metal parts are precisely formed through dry sand vibration molding and negative pressure pouring.

[0003] This process involves embedding a foam model coated with a refractory coating into dry sand without binder. When the high-temperature molten metal is poured, the model vaporizes and disappears, and the molten metal occupies the space of the model and solidifies to form a casting. Compared with traditional sand casting, this technology has significant advantages: high casting dimensional accuracy, simplified production process, and less environmental pollution.

[0004] However, with the development of digital casting technology, higher requirements have been placed on the precise control of the vibratory table and sand box system. Traditional sand boxes lack an adaptive fixing structure. Especially for white molds with curved surfaces, irregular shapes, or offset centers of gravity, it is difficult to ensure that the pouring gate is vertical when placed manually. When the sand box enters the vibratory table, the white mold is prone to displacement or tilting under the action of three-dimensional vibration, which causes turbulence when the molten metal fills the mold, resulting in defects such as cold shuts, insufficient pouring, and local sand adhesion in the casting, making it difficult to meet the production needs of high-precision castings. Summary of the Invention

[0005] The purpose of this invention is to provide a digital casting lost foam molding device to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a digital casting lost foam molding device, comprising a vibrating table and a sand box body disposed on the top of the vibrating table, wherein a fixed base plate is disposed inside the sand box body, and a slidable lifting box is disposed at the bottom of the fixed base plate, wherein a plurality of positioning rods are elastically installed inside the lifting box, and a first through hole is provided on the top surface of the fixed base plate for the positioning rods to pass through, and the rod wall of the positioning rod is slidably fitted with the inner wall of the first through hole, and the top end of the positioning rod is rounded.

[0007] Preferably, a disc is provided at the bottom of the positioning rod, a folding air cylinder is provided on the bottom surface of the disc, a first elastic element is sleeved on the outside of the folding air cylinder, one end of the first elastic element is fixedly connected to the bottom surface of the disc, and the other end of the first elastic element is fixedly connected to the bottom surface of the inner wall of the lifting box; an air bag is provided at the bottom of the lifting box, and ventilation holes are opened on the bottom surface of the lifting box, the number of ventilation holes corresponding to the number of folding air cylinders, an air tube is inserted into the bottom of the air bag, and the interior of the folding air cylinder is connected to the interior of the air bag through the ventilation holes.

[0008] Preferably, a sealing cap is provided at the end of the trachea away from the airbag.

[0009] Preferably, the side wall of the lifting box is provided with a first spring, and the inner wall of the sand box is provided with a second spring corresponding to the first spring; the side wall of the lifting box is provided with a roller, and the inner wall of the sand box is provided with a slide rail for the roller to rotate; the top surface of the vibration table is provided with a damper, the outside of which is fitted with a tension spring, and the movable end of the damper is fixedly connected to the bottom surface of the lifting box, one end of the tension spring is fixedly connected to the bottom surface of the lifting box, and the other end of the tension spring is fixedly connected to the top surface of the vibration table.

[0010] Preferably, a control plate is elastically installed on the top of the fixed base plate. The top surface of the control plate has a second through hole for the positioning rod to pass through, and the bottom surface of the control plate has a top pressure hole for the top pressure rod to be inserted. The outer wall of the control plate is slidably attached to the inner wall of the sand box, and the rod wall of the positioning rod is slidably attached to the inner wall of the second through hole. When the molding sand is filled, it can press the control plate down. When the molding sand is filled to a certain weight, the bottom end of the top pressure rod pushes the lifting box down, and the lifting box drives several positioning rods to move down synchronously.

[0011] Preferably, a second elastic element is provided between the control plate and the fixed base plate.

[0012] Preferably, the top surface of the fixed base plate is provided with a groove, the bottom surface of the inner wall of the groove is provided with a sleeve, the inner wall of the sleeve is provided with an internal thread, the inside of the sleeve is provided with a sliding cylinder, the outer wall of the sliding cylinder is provided with an external thread that matches the internal thread, the top surface of the sliding cylinder is provided with a limiting hole, and one end of the second elastic element is fixedly connected to the bottom surface of the control plate, the other end of the second elastic element is fixedly connected to the top surface of the sliding cylinder, and the top pressure rod slides inside the limiting hole; the inner wall of the sand box body is provided with a stop plate for limiting the height of the control plate.

[0013] Preferably, the outer wall of the sleeve is provided with a plurality of rotating holes, the outer wall of the fixed base plate is provided with a first through groove corresponding to the rotating holes, and the outer wall of the sand box body is provided with a second through groove corresponding to the first through groove.

[0014] Preferably, the side wall of the lifting box is provided with a pull rod, the outer wall of the sand box body is provided with a third through groove for the pull rod to slide, and the end of the air pipe away from the airbag passes through the third through groove.

[0015] Compared with the prior art, the beneficial effects of the present invention are:

[0016] 1. When the white mold is placed, its gravity presses the positioning rods downward, driving the folding air cylinder to compress and expel the internal air through the air pipe. After the sealing cover closes the air pipe, the positioning rod system forms a closed air resistance environment. Under the action of air pressure difference, all positioning rods are rigidly locked. This design, through an array of positioning rods that can be raised and lowered independently, provides three-dimensional support for the bottom of white molds with complex curved surfaces or irregular structures such as impellers and cylinders, ensuring the stability of irregularly shaped white molds. Compared with the traditional manual sand padding method, it fundamentally eliminates defects such as cold shuts and insufficient pouring caused by the tilting of the white mold. Especially for white molds with a shifted center of gravity, this design can automatically compensate for the force differences of each positioning rod, ensuring the full circumferential stability of complex structures.

[0017] 2. When the molding sand is filled to the critical weight (usually 70%-80% of the total weight of the sand box), the control plate is pressed down, and the top pressure rod drives the lifting box to disengage from the first and second spring plates. Under the control of the tension spring and damper, the positioning rod slowly descends, ensuring that the positioning rod begins to hide when the sand particles can flow and fill the gaps. At the same time, it can prevent the positioning rod from rapidly retracting and disturbing the white mold. The vibration table vibrates synchronously so that the sand particles fill the gaps in real time, and the positioning rod can eventually be completely hidden in the first through hole. Its top arc guides the sand flow to cover it, avoiding the positioning rod from affecting the casting process.

[0018] 3. By using an external straight rod to extend into the rotating hole and drive the sleeve to rotate, the preload of the second elastic element can be precisely set, thus adapting to different working conditions and simultaneously compensating for differences in sand mold density, such as between alumina sand and quartz sand, as well as fluctuations in vibration intensity. This ensures that the positioning rod is completely hidden when the molding sand is filled to the optimal time, the gaps are filled, and the white mold is stable, fundamentally eliminating the defects of iron-clad sand at the bottom of the casting and the problem of gate skew. In addition, this design can also quickly compensate for the stiffness reduction caused by fatigue of the second elastic element, significantly improving equipment adaptability and production efficiency. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0020] Figure 2 This is a schematic diagram of the installation of the sand box body in this invention;

[0021] Figure 3 This is a schematic diagram of the interior of the sand box body in this invention;

[0022] Figure 4 For the present invention Figure 3 Enlarged view of point A in the middle;

[0023] Figure 5 This is a schematic diagram of the installation of the positioning rod in this invention;

[0024] Figure 6This is a schematic diagram of the installation of the top pressure rod in this invention;

[0025] Figure 7 This is a schematic diagram of the interior of the lifting box in this invention;

[0026] Figure 8 For the present invention Figure 7 Enlarged view of point B in the middle;

[0027] Figure 9 This is a schematic diagram of the installation of the sliding cylinder in this invention;

[0028] Figure 10 This is a perspective view of the fixed base plate in this invention.

[0029] The components represented by each number in the attached diagram are listed below: 1. Vibration table; 2. Sand box body; 3. Fixed base plate; 4. Lifting box; 5. Positioning rod; 6. Disc; 7. First elastic element; 8. First through hole; 9. Airbag; 10. Air pipe; 11. Folding air cylinder; 12. Vent hole; 13. Sealing cover; 14. Control panel; 15. Second through hole; 16. Second elastic element; 17. Top pressure rod; 18. Top pressure hole; 19. First spring; 20. Second spring; 21. Roller; 22. Slide rail; 23. Tension spring; 24. Damper; 25. Groove; 26. Sleeve; 27. Sliding cylinder; 28. External thread; 29. ​​Internal thread; 30. Rotation hole; 31. Limiting hole; 32. First through groove; 33. Second through groove; 34. Pull rod; 35. Third through groove; 36. Support plate. Detailed Implementation

[0030] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] This invention provides a technical solution: such as Figures 1-10 The device shown is a digital casting lost foam molding device, including a vibrating table 1 and a sand box 2 fixedly installed on the top of the vibrating table 1. A fixed base plate 3 is fixedly installed inside the sand box 2. A sliding lifting box 4 is provided at the bottom of the fixed base plate 3. Several positioning rods 5 are elastically installed inside the lifting box 4. A first through hole 8 is opened on the top surface of the fixed base plate 3 for the positioning rods 5 to pass through, and the rod wall of the positioning rod 5 slides and fits against the inner wall of the first through hole 8. The top end of the positioning rod 5 is rounded.

[0032] A disc 6 is fixedly installed at the bottom of the positioning rod 5. A folding air cylinder 11 is fixedly installed on the bottom surface of the disc 6. A first elastic element 7 is sleeved on the outside of the folding air cylinder 11. One end of the first elastic element 7 is fixedly connected to the bottom surface of the disc 6, and the other end of the first elastic element 7 is fixedly connected to the bottom surface of the inner wall of the lifting box 4. An air bag 9 is fixedly installed at the bottom of the lifting box 4. A ventilation hole 12 is opened on the bottom surface of the lifting box 4. The number of ventilation holes 12 corresponds to the number of folding air cylinders 11. An air tube 10 is inserted into the bottom of the air bag 9, and the interior of the folding air cylinder 11 is connected to the interior of the air bag 9 through the ventilation hole 12.

[0033] A sealing cap 13 is provided at the end of the trachea 10 away from the airbag 9.

[0034] A first spring 19 is fixedly installed on the side wall of the lifting box 4, and a second spring 20 corresponding to the first spring 19 is fixedly installed on the inner wall of the sand box 2; a roller 21 is rotatably installed on the side wall of the lifting box 4, and a slide rail 22 for the roller 21 to rotate is fixedly installed on the inner wall of the sand box 2; a damper 24 is fixedly installed on the top surface of the vibration table 1, and a tension spring 23 is sleeved on the outside of the damper 24, and the movable end of the damper 24 is fixedly connected to the bottom surface of the lifting box 4, one end of the tension spring 23 is fixedly connected to the bottom surface of the lifting box 4, and the other end of the tension spring 23 is fixedly connected to the top surface of the vibration table 1.

[0035] A control plate 14 is elastically installed on the top of the fixed base plate 3. The top surface of the control plate 14 has a second through hole 15 for the positioning rod 5 to pass through, and the bottom surface of the control plate 14 has a top pressure hole 18 for the top pressure rod 17 to be inserted. The outer wall of the control plate 14 slides against the inner wall of the sand box 2, and the rod wall of the positioning rod 5 slides against the inner wall of the second through hole 15. When the molding sand is filled, it can press the control plate 14 down. When the molding sand is filled to a certain weight, the bottom end of the top pressure rod 17 pushes the lifting box 4 down, and the lifting box 4 drives several positioning rods 5 to move down synchronously.

[0036] A second elastic element 16 is provided between the control panel 14 and the fixed base plate 3.

[0037] The top surface of the fixed base plate 3 is provided with a groove 25, and a sleeve 26 is rotatably installed on the bottom surface of the inner wall of the groove 25. The inner wall of the sleeve 26 is provided with an internal thread 29, and a sliding cylinder 27 is provided inside the sleeve 26. The outer wall of the sliding cylinder 27 is provided with an external thread 28 that matches the internal thread 29. A limiting hole 31 is provided on the top surface of the sliding cylinder 27, and one end of the second elastic member 16 is fixedly connected to the bottom surface of the control plate 14, and the other end of the second elastic member 16 is fixedly connected to the top surface of the sliding cylinder 27. The top pressure rod 17 slides inside the limiting hole 31. A stop plate 36 for limiting the height of the control plate 14 is fixedly installed on the inner wall of the sand box body 2.

[0038] The outer wall of the sleeve 26 has several rotating holes 30, the outer wall of the fixed base plate 3 has a first through groove 32 corresponding to the rotating holes 30, and the outer wall of the sand box body 2 has a second through groove 33 corresponding to the first through groove 32.

[0039] A pull rod 34 is fixedly installed on the side wall of the lifting box 4. A third through groove 35 is opened on the outer wall of the sand box 2 for the pull rod 34 to slide, and the end of the air pipe 10 away from the airbag 9 passes through the third through groove 35.

[0040] Working principle: When it is necessary to put an irregularly shaped white mold into the sand box 2, the operator first slides the lifting box 4 upward by pulling rod 34 until the first spring 19 and the second spring 20 are engaged together, and then removes the sealing cover 13 from the air pipe 10. It should be noted that the first spring 19 and the second spring 20 are both hollow hemispherical springs, which can temporarily fix the position of the pulling rod 34. During the sliding of the lifting box 4, the stability of the lifting box 4 can be improved by the cooperation between the roller 21 and the slide rail 22. At the same time, the tension spring 23 is stretched to generate elastic force, and the tops of several positioning rods 5 extend to the top of the control plate 14.

[0041] Then, the workers place the white mold on several positioning rods 5. Under the action of the white mold's gravity, some of the positioning rods 5 can be pressed down according to the shape of the white mold. The downward movement of some positioning rods 5 can cause some of the first elastic element 7 and the folding air cylinder 11 to be compressed and folded. Subsequently, the excess air is discharged through the vent 12, air bag 9 and air pipe 10. After all the white molds have been placed, the sealing cover 13 is fixed to the air pipe 10 again. The sealing cover 13 and the air pipe 10 can be connected by threads. After the air outlet of the air pipe 10 is sealed by the sealing cover 13, the positions of several positioning rods 5 are relatively fixed, which further enhances the stability of the irregularly shaped white mold during the sand filling process and makes it less likely to tilt. It should be noted that the top of several positioning rods 5 is rounded. On the one hand, it can prevent the positioning rods 5 from damaging the white mold during vibration. On the other hand, when the molding sand falls to the top of the positioning rods 5, it can flow to all sides and will not accumulate at the top of the positioning rods 5, thus shortening the sand filling vibration time.

[0042] Then, molding sand can be poured into the sand box, and the vibrating table 1 vibrates. As more and more molding sand is poured in, it becomes heavier and heavier. The control plate 14 descends to the top surface of the fixed base plate 3. At the same time, the bottom end of the top pressure rod 17 pushes the lifting box 4 down. The first spring 19 separates from the second spring 20. Under the action of the tension spring 23 and the damping of the damper 24, the lifting box 4 synchronously drives several positioning rods 5 to slowly descend, so as to avoid the positioning rods 5 affecting the white mold during the casting process. Finally, under the action of the vibration of the vibrating table 1, the gaps of the original positioning rods 5 can be filled. It should be noted that when the lifting box 4 descends to the lowest position, the top of the positioning rod 5 is located inside the second through hole 15. The second through hole 15 is still in a blocked state, and the molding sand on the control plate 14 will not fall from the second through hole 15.

[0043] After the molding sand is filled, the high-temperature molten metal is poured into the white mold gate. The high-temperature molten metal vaporizes and decomposes the white mold upon contact. After the molten metal cools in the dry sand mold, it can accurately replicate the geometry of the white mold, forming a clean casting without flash or draft angle. After casting is completed, the casting and molding sand are removed, the sealing cover 13 is opened, and under the action of the elastic force of the first elastic element 7, part of the positioning rod 5 can be moved up again and the lifting box 4 is slid up to the initial position, so that the next casting can be cast again. It should be noted that the first elastic element 7 can be a compression spring or a return spring commonly used in the prior art, and a compression spring is preferred here.

[0044] By using an external straight rod inserted into the second through slot 33 and the first through slot 32, the end of the straight rod can be inserted into the rotating hole 30. This allows the sleeve 26 to rotate through several rotating holes 30. The rotation of the sleeve 26 can cause the sliding cylinder 27 to rise and fall. Combined with the height limit of the control plate 14 by the abutment plate 36, the preload of the second elastic element 16 can be precisely set, thus adapting to different working conditions. It should be noted that the groove 25 provides installation space for the sleeve 26 and the sliding cylinder 27. The second elastic element 16 can be a compression spring or a return spring commonly used in the prior art, and a compression spring is preferred here. Synchronous compensation for differences in sand mold density (such as pearl sand and quartz sand) and vibration intensity fluctuations ensures that the positioning rod 5 is completely hidden when the molding sand is filled to the optimal time (when the gaps can be filled and the white mold is stable), fundamentally eliminating the defects of iron-clad sand at the bottom of the casting and the problem of gate skew; in addition, the adjustable preload mechanism can quickly compensate for the stiffness reduction caused by the fatigue of the second elastic element 16, significantly improving the adaptability of the equipment and production efficiency, and achieving dynamic balance in lost foam manufacturing.

[0045] This device replaces a complex electrical control system with a mechanical structure, which significantly improves reliability while reducing costs. In addition, the lifting method of the lifting box 4 and the connection method of the air pipe 10 in this device can also be controlled by other electrical control equipment, but the cost will increase accordingly.

[0046] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0047] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A digitalized foundry lost foam molding device based on, comprising a vibrating table (1) and a sand box body (2) arranged on the top of the vibrating table (1), characterized in that: The inside of the sand box body (2) is provided with a fixed bottom plate (3), the bottom of the fixed bottom plate (3) is provided with a slidable lifting box (4), a plurality of positioning rods (5) are elastically mounted in the inside of the lifting box (4), the top surface of the fixed bottom plate (3) is provided with a first through hole (8) for the positioning rods (5) to pass through, and the rod wall of the positioning rod (5) is in sliding fit with the inner wall of the first through hole (8), and the top end of the positioning rod (5) is provided with a top end arc; The bottom end of the positioning rod (5) is provided with a disc (6), the bottom surface of the disc (6) is provided with a folding air cylinder (11), the outside of the folding air cylinder (11) is sleeved with a first elastic element (7), one end of the first elastic element (7) is fixedly connected with the bottom surface of the disc (6), and the other end of the first elastic element (7) is fixedly connected with the bottom surface of the inner wall of the lifting box (4); The bottom of the lifting box (4) is provided with an air bag (9), the bottom surface of the lifting box (4) is provided with a gas hole (12), the number of the gas holes (12) corresponds to the number of the folding air cylinders (11), the bottom of the air bag (9) is inserted with an air pipe (10), and the inside of the folding air cylinder (11) is in intercommunication with the inside of the air bag (9) through the gas hole (12); The top of the fixed bottom plate (3) is elastically mounted with a control plate (14), the top surface of the control plate (14) is provided with a second through hole (15) for the positioning rods (5) to pass through, the bottom surface of the control plate (14) is provided with a pressing hole (18) for the pressing rod (17) to insert, the outer wall of the control plate (14) is in sliding fit with the inner wall of the sand box body (2), the rod wall of the positioning rod (5) is in sliding fit with the inner wall of the second through hole (15), the sand filling can drive the control plate (14) to slide down, when the sand filling reaches the weight of the control plate (14) sliding down and driving the pressing rod (17) to push the lifting box (4) to move down, the bottom end of the pressing rod (17) pushes the lifting box (4) to move down, the lifting box (4) drives a plurality of positioning rods (5) to move down synchronously, the second elastic element (16) is arranged between the control plate (14) and the fixed bottom plate (3), the top surface of the fixed bottom plate (3) is provided with a groove (25), the bottom surface of the inner wall of the groove (25) is provided with a sleeve (26), the inner wall of the sleeve (26) is provided with an internal thread (29), the inside of the sleeve (26) is provided with a sliding cylinder (27), the outer wall of the sliding cylinder (27) is provided with an external thread (28) matched with the internal thread (29), the top surface of the sliding cylinder (27) is provided with a limiting hole (31), one end of the second elastic element (16) is fixedly connected with the bottom surface of the control plate (14), the other end of the second elastic element (16) is fixedly connected with the top surface of the sliding cylinder (27), and the pressing rod (17) slides in the limiting hole (31); The inner wall of the sand box body (2) is provided with a limiting plate (36) for limiting the height of the control plate (14).

2. The digitalized foundry lost pattern molding apparatus according to claim 1, wherein: The end of the air pipe (10) away from the air bag (9) is provided with a sealing cover (13).

3. The digitalized foundry lost pattern molding apparatus according to claim 2, wherein: The side wall of the lifting box (4) is provided with a first elastic sheet (19), and the inner wall of the sand box body (2) is provided with a second elastic sheet (20) corresponding to the first elastic sheet (19); The side wall of the lifting box (4) is provided with a roller (21), and the inner wall of the sand box body (2) is provided with a sliding rail (22) for the rotation of the roller (21); The top surface of the vibrating table (1) is provided with a damper (24), the outer part of the damper (24) is sleeved with a tension spring (23), the movable end of the damper (24) is fixedly connected with the bottom surface of the lifting box (4), one end of the tension spring (23) is fixedly connected with the bottom surface of the lifting box (4), and the other end of the tension spring (23) is fixedly connected with the top surface of the vibrating table (1).

4. The digitalized foundry lost pattern molding apparatus according to claim 3, wherein: The outer wall of the sleeve (26) is provided with a plurality of rotating holes (30), the outer wall of the fixed bottom plate (3) is provided with a first through groove (32) corresponding to the rotating hole (30), and the outer wall of the sand box body (2) is provided with a second through groove (33) corresponding to the first through groove (32).

5. The digitalized foundry lost pattern molding apparatus according to claim 4, wherein: The side wall of the lifting box (4) is provided with a pull rod (34), the outer wall of the sand box body (2) is provided with a third through groove (35) for the sliding of the pull rod (34), and one end of the air pipe (10) away from the air bag (9) penetrates through the third through groove (35).

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