Lost foam molding device based on digital casting

Abstract

The invention relates to the technical field of casting modeling, in particular to a digitized casting evanescent mode modeling device which comprises a jolt ramming table and a sand box body arranged at the top of the jolt ramming table, a fixed bottom plate is arranged in the sand box body, and a slidable lifting box is arranged at the bottom of the fixed bottom plate; a plurality of positioning rods are elastically installed in the lifting box, first through holes allowing the positioning rods to pass through are formed in the top face of the fixed bottom plate, the rod walls of the positioning rods are slidably attached to the inner walls of the first through holes, and the top ends of the positioning rods are arranged in an arc mode. The method has the beneficial effects that the bottom of the white mold in an irregular shape is attached to the outline of the positioning rod array, the placing stability of the white mold in the irregular shape is guaranteed, compared with a traditional manual sand padding fixing mode, the defects of cold shut, insufficient pouring and the like caused by inclination of the white mold are fundamentally overcome, and the equipment adaptability and the production efficiency are remarkably improved.

Description

Technical Field

[0001] The invention relates to the technical field of casting molding, in particular to a digital casting lost foam molding device. Background Art

[0002] Lost foam casting (also known as full-mold casting), as a representative process of green casting in the 21st century, focuses on replacing traditional metal or wooden molds with foam plastic models. The digital preparation of white molds is achieved through 3D scanning → topology optimization → CNC machining, and the precise forming of metal parts is achieved through dry sand vibration molding and negative pressure pouring.

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

[0004] However, with the development of digital casting technology, higher requirements are placed on the precise control of the vibration table and sand box system. The traditional sand box lacks an adaptive fixed structure. Especially for white molds with curved surfaces, special shapes or offset center of gravity, it is difficult to ensure the vertical pouring mouth when manually placed. When the sand box enters the vibration table, the white mold is prone to displacement or tilt under the action of three-dimensional vibration, resulting in turbulence when the molten metal fills the mold, causing defects such as cold shut, insufficient pouring, and local sand sticking to the casting, which makes it difficult to meet the production needs of high-precision castings. Summary of the Invention

[0005] The purpose of the present invention is to provide a digital casting lost foam molding device to solve the problems raised in the above background technology.

[0006] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a digital casting lost foam molding device, comprising a vibrating table and a sand box body arranged on the top of the vibrating table, the interior 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 installed inside the lifting box, a first through hole for the positioning rod to pass through is opened on the top surface of the fixed bottom plate, 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 set in an arc shape.

[0007] Preferably, a disc is provided at the bottom end of the positioning rod, a folding air cylinder is provided on the bottom surface of the disc, a first elastic member is sleeved on the outside of the folding air cylinder, and one end of the first elastic member is fixedly connected to the bottom surface of the disc, and the other end of the first elastic member 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 provided on the bottom surface of the lifting box, the number of ventilation holes corresponds to the number of folding air cylinders, an air pipe is inserted at 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 cover is provided at one end of the trachea away from the airbag.

[0009] Preferably, the side wall of the lifting box is provided with a first spring sheet, and the inner wall of the sand box body is provided with a second spring sheet corresponding to the first spring sheet; the side wall of the lifting box is provided with a roller, and the inner wall of the sand box body is provided with a slide rail for the rotation of the roller; the top surface of the compaction table is provided with a damper, the outer sleeve of the damper is provided 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 compaction table.

[0010] Preferably, a control plate is elastically mounted on the top of the fixed base plate, a second through hole is provided on the top surface of the control plate for the positioning rod to pass through, a top pressure hole is provided on the bottom surface of the control plate for the pushing rod to be inserted, and the outer wall of the control plate is slidably fitted with the inner wall of the sand box body, and the rod wall of the positioning rod is slidably fitted with the inner wall of the second through hole, so that the control plate can be pressed down when the molding sand is filled. When the molding sand is filled to a certain weight, the bottom end of the pushing rod pushes the lifting box down, and the lifting box drives several positioning rods to move down synchronously.

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

[0012] Preferably, a groove is provided on the top surface of the fixed bottom plate, a sleeve is provided on the bottom surface of the inner wall of the groove, an internal thread is provided on the inner wall of the sleeve, a sliding cylinder is provided inside the sleeve, and an external thread matching the internal thread is provided on the outer wall of the sliding cylinder. A limiting hole is provided on the top surface of the sliding cylinder, and one end of the second elastic member is fixedly connected to the bottom surface of the control plate, and the other end of the second elastic member is fixedly connected to the top surface of the sliding cylinder, and the pushing 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 rotation holes, the outer wall of the fixed bottom plate is provided with a first through slot corresponding to the rotation holes, and the outer wall of the flask body is provided with a second through slot corresponding to the first through slot.

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

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] 1. When the white mold is placed, its gravity presses the positioning rod downward, driving the folding air cylinder to compress and discharge the internal air through the air pipe. When the sealing cover closes the air pipe, the positioning rod system forms a closed air-blocking environment. Under the action of the air pressure difference, all positioning rods are rigidly locked. Through the independently liftable positioning rod array, this design provides three-dimensional fitting support for the bottom of the white mold with complex curved surfaces or special-shaped structures such as the impeller and cylinder body, ensuring the stability of the placement of irregular-shaped white molds. Compared with the traditional manual sand padding and fixing method, this design fundamentally eliminates defects such as cold shut and insufficient pouring caused by white mold tilt. Especially for white molds with offset center of gravity, this design can automatically compensate for the force differences between the positioning rods to ensure the full circumferential stability of the complex structure.

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

[0018] 3. By inserting an external straight rod into the rotating hole to drive the sleeve to rotate, the preload force of the second elastic member can be precisely set, thereby adapting to different working conditions and synchronously compensating for differences in sand mold density, such as between pearl sand and quartz sand, as well as fluctuations in vibration intensity. This ensures that the positioning rod is completely hidden when the sand is filled to the optimal time, the gap can be filled, and the white mold is stable, fundamentally eliminating the iron-encased sand defect at the bottom of the casting and the problem of gate deflection. In addition, this design can also quickly compensate for the stiffness attenuation caused by fatigue of the second elastic member, significantly improving equipment adaptability and production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It 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 the present invention;

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

[0022] Figure 4 For the present invention Figure 3 A magnified schematic diagram of point A in the middle;

[0023] Figure 5 Schematic diagram of the installation of the positioning rod in the present invention;

[0024] Figure 6Schematic diagram of the installation of the push rod in the present invention;

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

[0026] Figure 8 For the present invention Figure 7 An enlarged schematic diagram of point B;

[0027] Figure 9 Schematic diagram of the installation of the sliding cylinder of the present invention;

[0028] Figure 10 It is a three-dimensional diagram of the fixed base plate in the present invention.

[0029] In the accompanying drawings, the list of components represented by each reference number is as follows: 1. Vibrating table; 2. Sand box body; 3. Fixed bottom plate; 4. Lifting box; 5. Positioning rod; 6. Disc; 7. First elastic member; 8. First through hole; 9. Air bag; 10. Trachea; 11. Folding air cylinder; 12. Vent; 13. Sealing cover; 14. Control panel; 15. Second through hole; 16. Second elastic member; 17. Pressing rod; 18. Pressing 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. Rotating hole; 31. Limiting hole; 32. First through slot; 33. Second through slot; 34. Pull rod; 35. Third through slot; 36. Abutment plate. DETAILED DESCRIPTION

[0030] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0031] The present invention provides a technical solution: Figures 1-10 The shown device is a lost foam molding device based on digital casting, comprising a vibration table 1 and a sand box body 2 fixedly installed on the top of the vibration table 1, a fixed bottom plate 3 is fixedly installed inside the sand box body 2, a slidable lifting box 4 is provided at the bottom of the fixed bottom plate 3, and a plurality of positioning rods 5 are elastically installed inside the lifting box 4, a first through hole 8 for the positioning rod 5 to pass through is opened on the top surface of the fixed bottom plate 3, and the rod wall of the positioning rod 5 is slidably fitted with the inner wall of the first through hole 8, and the top end of the positioning rod 5 is set in an arc shape.

[0032] A disc 6 is fixedly installed on the bottom end of the positioning rod 5, and a folding air cylinder 11 is fixedly installed on the bottom surface of the disc 6. The outside of the folding air cylinder 11 is sleeved with a first elastic member 7, and one end of the first elastic member 7 is fixedly connected to the bottom surface of the disc 6, and the other end of the first elastic member 7 is fixedly connected to the bottom surface of the inner wall of the lifting box 4; an airbag 9 is fixedly installed on the bottom of the lifting box 4, and vent holes 12 are provided on the bottom surface of the lifting box 4. The number of vent holes 12 corresponds to the number of folding air cylinders 11. An air pipe 10 is inserted into the bottom of the airbag 9, and the interior of the folding air cylinder 11 is connected to the interior of the airbag 9 through the vent holes 12.

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

[0034] A first spring piece 19 is fixedly installed on the side wall of the lifting box 4, and a second spring piece 20 corresponding to the first spring piece 19 is fixedly installed on the inner wall of the sand box body 2; a roller 21 is rotatably installed on the side wall of the lifting box 4, and a slide rail 22 for rotation of the roller 21 is fixedly installed on the inner wall of the sand box body 2; a damper 24 is fixedly installed on the top surface of the compacting table 1, and the outer sleeve of the damper 24 is provided with a tension spring 23, 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 compacting table 1.

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

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

[0037] A groove 25 is provided on the top surface of the fixed base plate 3, 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, and the pushing 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 is provided with a plurality of rotation holes 30 , the outer wall of the fixed base plate 3 is provided with a first through slot 32 corresponding to the rotation holes 30 , and the outer wall of the flask body 2 is provided with a second through slot 33 corresponding to the first through slot 32 .

[0039] A pull rod 34 is fixedly mounted on the side wall of the lifting box 4 , a third through slot 35 for the pull rod 34 to slide is opened on the outer wall of the flask body 2 , and one end of the air pipe 10 away from the air bag 9 passes through the third through slot 35 .

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

[0041] After the mold is put in place, the sealing cover 13 is fixed on the trachea 10 again. The sealing cover 13 and the trachea 10 can be connected by a thread. After the air outlet end of the trachea 10 is sealed by the sealing cover 13, the positions of the several positioning rods 5 are relatively fixed, which further enhances the stability of the irregular-shaped white mold when it is fixed during the sand filling process, and is less likely to tilt. It should be noted that the arc setting at the top of the several positioning rods 5 can, on the one hand, prevent the positioning rods 5 from damaging the white mold during the vibration process, and on the other hand, when the molding sand falls to the top of the positioning rod 5, it can flow to the surroundings and will not accumulate at the top of the positioning rod 5, thereby shortening the vibration time of the sand filling.

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

[0043] After the molding sand is filled, high-temperature molten metal is poured into the white mold gate. The high-temperature molten metal instantly vaporizes and decomposes when it contacts the white mold. After the molten metal cools in the dry sand mold, it can accurately replicate the geometric shape of the white mold to form a net-shape casting without burrs and draft angles. After the casting is completed, the casting and molding sand are taken out, and the sealing cover 13 is opened. Under the action of the elastic force of the first elastic member 7, part of the positioning rod 5 can be driven to move up again, and the lifting box 4 can be slid up to the initial position, and the next casting can be cast again. It should be noted that the first elastic member 7 can be a compression spring or a return spring commonly used in the prior art, and a compression spring is preferably used here.

[0044] By using an external straight rod to extend into the second through slot 33 and the first through slot 32, the staff can make the end of the straight rod extend into the rotating hole 30, and then the sleeve 26 can be driven to rotate through several rotating holes 30. The rotation of the sleeve 26 can drive 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 force of the second elastic member 16 can be accurately set, so that it can adapt to different working conditions. It should be noted that the groove 25 is used to provide installation space for the sleeve 26 and the sliding cylinder 27. The second elastic member 16 can be a compression spring or a return spring commonly used in the prior art, and a compression spring is preferably used here. It synchronously compensates for differences in sand mold density (such as gem sand and quartz sand) and fluctuations in vibration intensity, ensuring that the positioning rod 5 is completely hidden when the sand is filled to the optimal time (when the gaps can be filled and the white mold is stable), fundamentally eliminating the iron-encased sand defects at the bottom of the casting and the gate deflection problem; in addition, the adjustable preload mechanism can quickly compensate for the stiffness attenuation caused by fatigue of the second elastic member 16, significantly improving the adaptability and production efficiency of the equipment and achieving dynamic balance in lost foam manufacturing.

[0045] This device replaces the complex electronic 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 electronic control equipment, but the cost will also increase accordingly.

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

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

Claims

1. A digital casting lost foam molding device, comprising a vibration table (1) and a sand box body (2) arranged on the top of the vibration table (1), characterized in that: A fixed bottom plate (3) is provided inside the sand box body (2), a slidable lifting box (4) is provided at the bottom of the fixed bottom plate (3), a plurality of positioning rods (5) are elastically installed inside the lifting box (4), a first through hole (8) for the positioning rod (5) to pass through is opened on the top surface of the fixed bottom plate (3), and the rod wall of the positioning rod (5) is slidably fitted with the inner wall of the first through hole (8), and the top end of the positioning rod (5) is arranged in a circular arc.

2. The digital casting lost foam molding device according to claim 1, characterized in that: A disc (6) is provided at the bottom end of the positioning rod (5), a folding air cylinder (11) is provided on the bottom surface of the disc (6), a first elastic member (7) is sleeved on the outside of the folding air cylinder (11), and one end of the first elastic member (7) is fixedly connected to the bottom surface of the disc (6), and the other end of the first elastic member (7) is fixedly connected to the bottom surface of the inner wall of the lifting box (4); An air bag (9) is provided at the bottom of the lifting box (4), and ventilation holes (12) are provided 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 holes (12).

3. The digital casting lost foam molding device according to claim 2, characterized in that: A sealing cover (13) is provided at one end of the trachea (10) away from the airbag (9).

4. The digital casting lost foam molding device according to claim 1, characterized in that: The side wall of the lifting box (4) is provided with a first elastic piece (19), and the inner wall of the sand box body (2) is provided with a second elastic piece (20) corresponding to the first elastic piece (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 slide rail (22) for the roller (21) to rotate; The top surface of the vibration table (1) is provided with a damper (24), the outer sleeve of the damper (24) is provided with a tension spring (23), 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).

5. The lost foam molding device based on digital casting according to claim 4 is characterized in that: A control plate (14) is elastically mounted on the top of the fixed bottom plate (3), a second through hole (15) for the positioning rod (5) to pass through is provided on the top surface of the control plate (14), a top pressure hole (18) for the top pressure rod (17) to be inserted is provided on the bottom surface of the control plate (14), and the outer wall of the control plate (14) is slidably fitted with the inner wall of the sand box body (2), and the rod wall of the positioning rod (5) is slidably fitted with the inner wall of the second through hole (15), so that the control plate (14) can be pressed down when the molding sand is filled. When the molding sand is filled to the weight of the control plate (14) sliding down and driving the top pressure rod (17) to push the lifting box (4) downward, the bottom end of the top pressure rod (17) pushes the lifting box (4) downward, and the lifting box (4) drives a plurality of positioning rods (5) to move downward synchronously.

6. The digital casting lost foam molding device according to claim 5, characterized in that: A second elastic member (16) is provided between the control plate (14) and the fixed base plate (3).

7. The lost foam molding device based on digital casting according to claim 6, characterized in that: The top surface of the fixed base 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 interior 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) adapted to the internal thread (29), the top surface of the sliding cylinder (27) is provided with a limiting hole (31), 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), and the pressing rod (17) slides inside the limiting hole (31); The inner wall of the sand box body (2) is provided with a stop plate (36) for limiting the height of the control plate (14).

8. The lost foam molding device based on digital casting according to claim 7 is characterized in that: The outer wall of the sleeve (26) is provided with a plurality of rotation holes (30), the outer wall of the fixed base plate (3) is provided with a first through slot (32) corresponding to the rotation holes (30), and the outer wall of the sand box body (2) is provided with a second through slot (33) corresponding to the first through slot (32).

9. The digital casting lost foam molding device according to claim 1, characterized in that: 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 slot (35) for the pull rod (34) to slide, and the end of the air pipe (10) away from the air bag (9) passes through the third through slot (35).

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