A composite sand mold casting device and method for middle trough of a scraper

Abstract

The application discloses a kind of composite sand mould casting device and method in middle slot of scraper, it is related to intelligent casting island technical field, the present application includes casting island mesa, the casting island mesa is equipped with mould body one and mould body two, bottom gate and riser are equipped between the mould body one and mould body two;It includes the following steps: S1: clean the cavity, keep its surface neat and smooth, clean bottom gate and riser at the same time, ensure its smooth, start servo motor to make mould body one and mould body two mutually adhere to each other.The advantage is that: the present application uses composite sand mould, effectively improves the anti-sticking sand, the anti-scouring ability and the yielding property, so that the quality of casting is guaranteed, and the movement of mould body one and mould body two during demoulding can automatically complete the support and transfer of casting after demoulding, without manual control, reduces process linking time, avoids collision during transfer to cause surface damage of casting.

Description

Technical Field

[0001] This invention relates to the field of intelligent casting island technology, and in particular to a composite sand casting device and method for the central trough of a scraper conveyor. Background Technology

[0002] The central trough of the scraper conveyor is the core load-bearing and conveying component of the scraper conveyor. It is mainly composed of the trough sides, middle plate, bottom plate and connecting structure. It serves as the running channel of the scraper chain to transport materials such as coal and gangue, and also as the walking track of the coal mining machine to withstand impact and wear. Therefore, the overall strength, wear resistance and dimensional accuracy of the casting are required to be extremely high. The mainstream casting materials are high manganese steel or low alloy wear-resistant steel.

[0003] With the intelligent upgrading of the casting industry, intelligent casting islands, which can integrate the entire process of smelting, molding, pouring, and cleaning into automated operations, have greatly improved production efficiency and quality consistency, and have been gradually applied to the large-scale casting of the middle trough of scraper conveyors.

[0004] Existing intelligent casting islands typically use traditional single sand molds for molding. However, when adapted to the middle trough casting of scraper conveyors, the sand mold strength is insufficient, affecting the casting quality and subsequent performance. Furthermore, the demolding mechanisms of existing intelligent casting islands mostly only have sand mold separation functions and do not integrate support components adapted to the casting. After demolding, the casting is prone to local deformation due to its own weight, and additional manual labor or external equipment is required to transfer it to the next process. This not only increases the process connection time but may also cause surface damage to the casting due to collisions during the transfer process. Therefore, it is necessary to design a composite sand mold casting device and method for the middle trough of a scraper conveyor. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a composite sand casting device and method for the middle trough of a scraper conveyor, which solves the problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A composite sand casting device for the middle trough of a scraper conveyor includes a casting island platform. The casting island platform is provided with a mold body one and a mold body two. A bottom pouring port and a riser are provided between the mold body one and the mold body two. The mold body one and the mold body two are composed of a metal layer, a relief layer and a high-strength molding sand layer from the outside to the inside. A cavity is formed between the two high-strength molding sand layers, and the cavity is interconnected with the bottom pouring port and the riser.

[0008] The casting island platform is provided with a sliding component that cooperates with mold body one and mold body two. The sliding component is used to control the separation or docking of mold body one and mold body two. The sliding component includes a rotating rod that is rotatably installed in the casting island platform.

[0009] A through groove is provided in the middle of the casting island platform, and a support plate is slidably installed in the through groove. A buffer plate is installed on the support plate through a lifting component, and a support platform is installed on the buffer plate. A synchronization component that cooperates with the support plate and the rotating rod is installed on the casting island platform, and a drive component that cooperates with the lifting component is installed on the casting island platform.

[0010] Furthermore, two sliding grooves and two sliding grooves are provided on the casting island platform. A slider 1, which is fixedly connected to the mold body 1, is slidably installed in each of the two sliding grooves 1. A slider 2, which is fixedly connected to the mold body 2, is slidably installed in each of the two sliding grooves 2. A lead screw 1 and a lead screw 2 are fixedly installed at both ends of the rotating rod, respectively. The lead screw 1 is threadedly connected to the slider 1, and the lead screw 2 is threadedly connected to the slider 2. A servo motor is fixedly installed on the side wall of the casting island platform, and the output end of the servo motor is fixedly connected to one end of the lead screw 2.

[0011] Furthermore, two movable slots are provided in the through groove, and movable blocks that are fixedly connected to the support plate are slidably installed in both movable slots.

[0012] Furthermore, the synchronization component consists of a lead screw three, a bevel gear one, and a bevel gear two. The lead screw three is rotatably installed in one of the moving slots and is threadedly connected to the corresponding moving block. The bevel gear one is fixedly installed on the rotating rod, and the bevel gear two is fixedly installed on the lead screw three, and the bevel gear two meshes with the bevel gear one.

[0013] Furthermore, multiple springs are installed between the buffer plate and the support platform, and a guide post is fixedly installed at the bottom of the support platform to slide up and down with the buffer plate.

[0014] Furthermore, the lifting assembly consists of a connecting groove, a connecting plate, and a lead screw. The connecting groove is formed on the support plate, and the connecting plate is slidably installed in the connecting groove. The connecting plate is fixedly connected to the buffer plate. The lead screw is rotatably installed on the support plate, and one end of the lead screw located in the connecting groove is threadedly connected to the connecting plate.

[0015] Furthermore, the drive assembly comprises a fixed base, a connecting rod, a third bevel gear, a fourth bevel gear, a fixed gear, a groove, and a fixed rack. The fixed base is fixedly installed on the bottom of the support plate, the connecting rod is rotatably installed on the fixed base, the third bevel gear is fixedly installed on the connecting rod, the fourth bevel gear is fixedly installed on the end of the fourth lead screw located outside the support plate, and the fourth bevel gear meshes with the third bevel gear. The fixed gear is fixedly installed on the other end of the connecting rod, the groove is formed on the side wall of the through groove, and the groove cooperates with the fixed gear. The fixed rack is fixedly installed in the groove, and the fixed rack cooperates with the fixed gear.

[0016] Furthermore, the length of the fixed rack is less than or equal to the difference between the width of the through groove and the width of the buffer plate, the screws one and two have opposite directions of rotation, and the pitch of screw one is less than the pitch of screw two. The two sides of the support platform are arc-shaped.

[0017] A casting method for the middle trough of a scraper conveyor, using the aforementioned composite sand casting device for the middle trough of a scraper conveyor, includes the following steps:

[0018] S1: Clean the cavity to keep its surface clean and smooth. At the same time, clean the bottom gate and riser to ensure that they are unobstructed. Start the servo motor to make mold body one and mold body two fit together.

[0019] S2: Select high-quality scrap steel with low sulfur and low phosphorus, and use high-carbon ferromanganese or ferrochrome as smelting material. Bake the alloy material to be used at 200-300℃ for 2-3 hours to remove moisture and volatiles and avoid the generation of porosity during smelting.

[0020] S3: Use a 10t medium-frequency induction furnace to melt the materials. The order of adding materials is as follows: first add scrap steel, then add recycled materials, and finally add high-carbon ferromanganese, ferrochrome or alloy materials. Avoid adding alloy materials first, which may cause burn-off. After the molten metal is completely melted, raise the temperature to 1500-1550℃ and hold for 30-40 minutes to ensure uniform composition.

[0021] S4: First, add 0.5% ferrosilicon for pre-deoxidation to the molten liquid, and then add 0.15% aluminum for final deoxidation after 10 minutes to ensure that the oxygen content is ≤0.003%. Then, introduce argon gas at a flow rate of 0.8-1.0 L / min and stir for 15-20 minutes to control the hydrogen content to ≤0.0003% to avoid subcutaneous porosity. Take a sample of the molten liquid before it is removed from the furnace and analyze its composition with a direct-reading spectrometer to ensure that it meets the material standards. If it does not meet the standards, add alloy material to adjust it.

[0022] S5: Preheat the casting ladle to 800-1000℃, place a φ2mm high-temperature resistant metal filter screen at the inlet of the ingate, preheat the high-strength molding sand layer to 50-80℃, and blow the cavity with compressed air to remove residual sand particles.

[0023] S6: Pour from the bottom sprue until the cavity is full. Pour 1-2 times into the riser, with each pour being 1 / 5 of the riser volume, to ensure continuous feeding of the riser and reduce shrinkage cavities.

[0024] S7: Close the pouring gate and allow the casting to cool naturally in the high-strength molding sand layer. The cooling rate is controlled at ≤30℃ / h to avoid excessive temperature difference and thermal stress. When the casting temperature cools to ≤150℃, the servo motor is started in reverse to separate mold body one and mold body two. During this process, the rotation of the rotating rod drives the screw three to rotate simultaneously through the meshing of bevel gear one and bevel gear two. The support plate drives the support platform to move on the casting island platform through the buffer plate.

[0025] S8: When the support plate starts to move, the buffer plate drives the support platform to move up through the cooperation of the drive component and the lifting component. After the mold body one and mold body two separate, the support platform supports the bottom of the casting in the cavity and moves the casting away from the casting island platform as the support plate moves. At this time, the workers can cut the gating gate of the casting and use the hoisting device or conveyor belt to send the casting into the shot blasting machine for surface treatment. After that, the surface-treated casting is put into the heating furnace for heating treatment to ensure that the carbides are completely dissolved. Then, it is quickly water quenched to obtain the middle groove of the scraper machine.

[0026] Compared with existing technologies, the advantages of this invention are:

[0027] 1. By designing the metal layer, the relief layer, and the high-strength molding sand layer, the anti-sand adhesion and anti-erosion ability of the sand mold surface layer can be effectively improved, and the relief of the sand mold is stronger, reducing the risk of cracks when the casting cools and shrinks, thus effectively ensuring the quality of the casting.

[0028] 2: The support platform design effectively supports the bottom of the casting after demolding, preventing local deformation caused by the casting's own weight. It also allows the casting to be rotated to the next process, reducing process connection time and preventing surface damage to the casting due to collisions during transportation.

[0029] 3: Through the cooperation of sliding components, synchronization components, drive components and lifting components, the height and left and right position of the support platform can be automatically controlled according to the movement of mold body one and mold body two, so that it can automatically support and transfer the casting after demolding without manual control, which greatly improves the degree of automation.

[0030] In summary, the present invention effectively improves the anti-sand adhesion, anti-erosion and yielding properties by using composite sand molds, thus ensuring the quality of castings. At the same time, the movement of mold body one and mold body two during the demolding process can automatically complete the support and transfer of the castings after demolding, without the need for manual control, reducing the process connection time and avoiding surface damage to the castings caused by collisions during the transfer process. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the structure of a composite sand casting device for the middle trough of a scraper conveyor proposed in this invention;

[0032] Figure 2 for Figure 1 Top view;

[0033] Figure 3 for Figure 2 Schematic diagram of the structure of surface AA;

[0034] Figure 4 for Figure 2 Schematic diagram of the structure of the middle BB surface;

[0035] Figure 5 for Figure 1 A structural schematic diagram of the central casting island platform from another perspective;

[0036] Figure 6 for Figure 5 Internal structure diagram;

[0037] Figure 7 for Figure 6 A bottom view;

[0038] Figure 8 for Figure 7 Schematic diagram of the structure of the C-plane;

[0039] Figure 9 for Figure 6 A structural decomposition diagram;

[0040] Figure 10 for Figure 9 Enlarged structural diagram of section D.

[0041] In the diagram: 1 Casting island platform, 2 Mold body one, 3 Mold body two, 4 Cavity, 5 Bottom sprue, 6 Riser, 7 Recessed layer, 8 High-strength molding sand layer, 9 Slide one, 10 Slide two, 11 Servo motor, 12 Rotary rod, 13 Lead screw one, 14 Lead screw two, 15 Through groove, 16 Moving groove, 17 Moving block, 18 Support plate, 19 Lead screw three, 20 Bevel gear one, 21 Bevel gear two, 22 Buffer plate, 23 Spring, 24 Support platform, 25 Guide column, 26 Connecting plate, 27 Lead screw four, 28 Fixed seat, 29 Connecting rod, 30 Bevel gear three, 31 Bevel gear four, 32 Fixed gear, 33 Groove, 34 Fixed rack. Detailed Implementation

[0042] Reference Figures 1-10A composite sand casting device for the middle trough of a scraper conveyor includes a casting island platform 1. The casting island platform 1 is provided with a first mold body 2 and a second mold body 3. A bottom inlet 5 and a riser 6 are fitted between the first mold body 2 and the second mold body 3. The bottom inlet 5 has a diameter of 80-100mm (adjusted according to the weight of the casting). The riser 6 is stepped. Both the first mold body 2 and the second mold body 3 are composed of a metal layer, a relief layer 7, and a high-strength molding sand layer 8 from the outside to the inside. A cavity 4 is formed between the two high-strength molding sand layers 8. Cavity 4 is interconnected with bottom inlet 5 and riser 6. The metal layer is made of wear-resistant metal. The relief layer 7 uses ordinary quartz sand with resin binder to reduce the overall material cost. At the same time, the addition of wood chips (accounting for 3%-5%) improves the sand mold's relief and reduces the risk of cracking during casting cooling and shrinkage. The high-strength molding sand layer 8 uses high refractory materials (such as zircon sand mixed with corundum powder) with a thickness of 50-80mm. It is designed for easily worn parts such as the middle plate chain track and the load-bearing surface of the groove side to improve the anti-sticking sand and anti-erosion capabilities.

[0043] The casting island platform 1 is equipped with a sliding assembly that cooperates with mold body 2 and mold body 3. The sliding assembly is used to control the separation or docking of mold body 2 and mold body 3. When mold body 2 and mold body 3 are docked and fitted together, they form a complete sand mold for casting the middle groove of the scraper machine. The sliding assembly includes a rotating rod 12 rotatably installed in the casting island platform 1. The casting island platform 1 has two sliding grooves 9 and two sliding grooves 10. Sliding slider 1, which is fixedly connected to mold body 2, is slidably installed in each of the two sliding grooves 9. Sliding slider 2, which is fixedly connected to mold body 3, is slidably installed in each of the two sliding grooves 10. Lead screw 13 and lead screw 14 are fixedly installed at both ends of the rotating rod 12, respectively. Lead screw 13 is threadedly connected to slider 1. 4. A servo motor 11 is fixedly installed on the side wall of the casting island platform 1, and the output end of the servo motor 11 is fixedly connected to one end of the lead screw 14. The servo motor 11 can be an ACM6004M2H model servo motor. When the servo motor 11 is working, it drives the lead screw 13 and lead screw 14 to rotate simultaneously. At this time, the mold body 12 and the mold body 23 can move closer or further away from each other, realizing the separation or contact of the two. The screw 13 and the lead screw 24 have opposite directions of rotation, and the pitch of the lead screw 13 is smaller than the pitch of the lead screw 24. The pitch here is designed so that when the servo motor 11 is working, the mold body 12 and the mold body 23, which need to move different distances, can move in opposite directions to the maximum distance at the same time.

[0044] A through groove 15 is provided in the middle of the casting island platform 1, and a support plate 18 is slidably installed in the through groove 15. Two movable grooves 16 are provided in the through groove 15, and movable blocks 17 fixedly connected to the support plate 18 are slidably installed in both movable grooves 16. A buffer plate 22 is installed on the support plate 18 through a lifting assembly, and a support platform 24 is installed on the buffer plate 22. The support platform 24 is used to support the bottom of the formed casting to avoid local deformation due to its own weight.

[0045] A synchronization assembly is installed on the casting island platform 1 to cooperate with the support plate 18 and the rotating rod 12. The synchronization assembly consists of a lead screw 19, a bevel gear 20, and a bevel gear 21. The lead screw 19 is rotatably installed in one of the moving slots 16 and is threadedly connected to the corresponding moving block 17. The bevel gear 20 is fixedly installed on the rotating rod 12, and the bevel gear 21 is fixedly installed on the lead screw 19, and the bevel gear 21 meshes with the bevel gear 20. When the rotating rod 12 rotates, the meshing effect of the bevel gear 20 and the bevel gear 21 causes the lead screw 19 to rotate simultaneously, thereby causing the support plate 18 to move synchronously within the through slot 15. The specific direction of movement is as follows: Figure 4 As shown, when mold body 1 2 and mold body 2 3 are attached, the support plate 18 is located at the leftmost position in the through groove 15. Then, when mold body 1 2 and mold body 2 3 move away from each other, the support plate 18 moves from left to right in the through groove 15. When mold body 1 2 and mold body 2 3 move closer to each other, the support plate 18 moves from right to left in the through groove 15.

[0046] Multiple springs 23 are installed between the buffer plate 22 and the support platform 24. A guide post 25 is fixedly installed at the bottom of the support platform 24, which slides vertically with the buffer plate 22. The design of the guide post 25 allows the support platform 24 to remain horizontal relative to the buffer plate 22. The design of the springs 23 allows the support platform 24 to move downwards relative to the buffer plate 22 when subjected to a large external force. Therefore, in the initial demolding stage, when mold body 1 2 and mold body 2 3 have not separated by a sufficient distance, the height limitation of mold body 1 2 and mold body 2 3 will cause the springs 23 to be compressed, allowing the support platform 24 to subsequently move downwards relative to the buffer plate 22. After the second mold body 3 separates to a sufficient distance, it moves upward smoothly to support the casting. The total elastic force of the multiple springs 23 is greater than or equal to the weight of the casting. The support platform 24 has an arc shape on both sides. The advantage of this shape design is that after the casting is completed and transported, during the process of the first mold body 2 and the second mold body 3 resetting and approaching each other, the arc surface of the support platform 24 first contacts the bottom of the first mold body 2 and the second mold body 3. At this time, the compression of the support platform 24 by the first mold body 2 and the second mold body 3 will make it overcome the elastic force of the springs 23 and move downward, ensuring that the first mold body 2 and the second mold body 3 can smoothly approach and fit together.

[0047] The lifting assembly consists of a connecting groove, a connecting plate 26, and a lead screw 27. The connecting groove is opened on the support plate 18. The connecting plate 26 is slidably installed in the connecting groove and is fixedly connected to the buffer plate 22. The lead screw 27 is rotatably installed on the support plate 18, and one end of the lead screw 27 located in the connecting groove is threadedly connected to the connecting plate 26. A drive assembly that cooperates with the lifting assembly is installed on the casting island platform 1. The drive assembly consists of a fixed base 28, a connecting rod 29, a bevel gear 30, a bevel gear 4 31, a fixed gear 32, a groove 33, and a fixed rack 34.

[0048] The fixed seat 28 is fixedly installed at the bottom of the support plate 18. The connecting rod 29 is rotatably installed on the fixed seat 28. The bevel gear 30 is fixedly installed on the connecting rod 29. The bevel gear 4 31 is fixedly installed at one end of the screw 4 27 located outside the support plate 18, and the bevel gear 4 31 meshes with the bevel gear 30. The fixed gear 32 is fixedly installed at the other end of the connecting rod 29. The groove 33 is opened on the side wall of the through groove 15, and the groove 33 cooperates with the fixed gear 32. The fixed rack 34 is fixedly installed in the groove 33, and the fixed rack 34 cooperates with the fixed gear 32. When the support plate 18 moves to the right in the through groove 15 ( Figure 4 (As shown in the direction), the meshing effect of the fixed rack 34 and the fixed gear 32 causes the connecting rod 29 to rotate clockwise. At this time, under the meshing effect of the bevel gear 31 and the bevel gear 30, the lead screw 27 rotates simultaneously, causing the connecting plate 26 to move upward in the connecting groove, thereby allowing the support platform 24 to move upward. The length of the fixed rack 34 is less than or equal to the difference between the width of the through groove 15 and the buffer plate 22. The advantage of this size design is that it allows the buffer plate 22 to rise smoothly to the outside of the through groove 15 in the initial stage of the movement of the support plate 18, avoiding the buffer plate 22 contacting the through groove 15 and causing the movement of the support plate 18 to be obstructed.

[0049] In this invention, a casting method for the middle groove of a scraper machine includes the following steps: S1: Clean the cavity 4 to keep its surface clean and smooth, and clean the bottom pouring port 5 and riser 6 to ensure that they are unobstructed; start the servo motor 11 to make the mold body 1 2 and the mold body 2 3 fit together.

[0050] S2: Select high-quality scrap steel with low sulfur and low phosphorus, and use high-carbon ferromanganese or ferrochrome as smelting material. Bake the alloy material to be used at 200-300℃ for 2-3 hours to remove moisture and volatiles and avoid the generation of porosity during smelting.

[0051] S3: Use a 10t medium-frequency induction furnace to melt the materials. The order of adding materials is as follows: first add scrap steel, then add recycled materials, and finally add high-carbon ferromanganese, ferrochrome or alloy materials. Avoid adding alloy materials first, which may cause burn-off. After the molten metal is completely melted, raise the temperature to 1500-1550℃ and hold for 30-40 minutes to ensure uniform composition.

[0052] S4: First, add 0.5% ferrosilicon for pre-deoxidation to the molten liquid, and then add 0.15% aluminum for final deoxidation after 10 minutes to ensure that the oxygen content is ≤0.003%. Then, introduce argon gas at a flow rate of 0.8-1.0 L / min and stir for 15-20 minutes to control the hydrogen content to ≤0.0003% to avoid subcutaneous porosity. Take a sample of the molten liquid before it is removed from the furnace and analyze its composition with a direct-reading spectrometer to ensure that it meets the material standards. If it does not meet the standards, add alloy material to adjust it.

[0053] S5: Preheat the casting ladle to 800-1000℃, place a φ2mm high-temperature resistant metal filter screen at the inlet of the ingate, preheat the high-strength molding sand layer 8 to 50-80℃, and blow the cavity 4 with compressed air to remove residual sand particles.

[0054] S6: Pour from the bottom inlet 5 until the cavity 4 is full. Pour 1-2 times into the riser 6, with each pour being 1 / 5 of the riser 6 volume, to ensure continuous feeding of the riser 6 and reduce shrinkage cavities.

[0055] S7: Close the pouring gate and allow the casting to cool naturally in the high-strength molding sand layer 8. The cooling rate is controlled at ≤30℃ / h to avoid excessive temperature difference and thermal stress. When the casting temperature cools to ≤150℃, the servo motor 11 is started in reverse to separate the mold body 1 2 and the mold body 2 3. During this process, the rotation of the rotating rod 12 drives the lead screw 3 19 to rotate simultaneously through the meshing of the bevel gear 1 20 and the bevel gear 2 21. The support plate 18 drives the support platform 24 to move on the casting island platform 1 through the buffer plate 22.

[0056] S8: When the support plate 18 starts to move, the buffer plate 22 drives the support platform 24 to move upward through the cooperation of the drive component and the lifting component. After the mold body 1 2 and the mold body 2 3 are separated, the support platform 24 supports the bottom of the casting in the cavity 4 and moves the casting away from the casting island platform 1 as the support plate 18 moves. At this time, the workers can cut the gating gate of the casting and use the hoisting device or conveyor belt to send the casting into the shot blasting machine for surface treatment. After that, the surface-treated casting is put into the heating furnace for heating treatment to ensure that the carbides are completely dissolved. Then, it is quickly water quenched to obtain the middle groove of the scraper machine.

[0057] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed invention.

Claims

1. A composite sand casting device for the middle trough of a scraper conveyor, comprising a casting island platform (1), wherein a first mold body (2) and a second mold body (3) are provided on the casting island platform (1), characterized in that, The mold body one (2) and the mold body two (3) are provided with a bottom injection port (5) and a riser (6). The mold body one (2) and the mold body two (3) are composed of a metal layer, a relief layer (7) and a high-strength molding sand layer (8) from the outside to the inside. The two high-strength molding sand layers (8) form a cavity (4), and the cavity (4) is interconnected with the bottom injection port (5) and the riser (6). The casting island platform (1) is provided with a sliding component that cooperates with mold body one (2) and mold body two (3). The sliding component is used to control the separation or docking of mold body one (2) and mold body two (3). The sliding component includes a rotating rod (12) that is rotatably installed in the casting island platform (1). The casting island platform (1) has a through groove (15) in the middle, and a support plate (18) is slidably installed in the through groove (15). Two moving grooves (16) are opened in the through groove (15), and moving blocks (17) fixedly connected to the support plate (18) are slidably installed in both moving grooves (16). A buffer plate (22) is installed on the support plate (18) through a lifting assembly, and a support platform (24) is installed on the buffer plate (22). Multiple springs (23) are installed between the buffer plate (22) and the support platform (24). A guide column (25) that slides up and down with the buffer plate (22) is fixedly installed at the bottom of the support platform (24). A synchronization assembly that cooperates with the support plate (18) and the rotating rod (12) is installed on the casting island platform (1). A drive assembly that cooperates with the lifting assembly is installed on the casting island platform (1). The casting island platform (1) has two sliding grooves (9) and two sliding grooves (10). Slider 1, which is fixedly connected to mold body 1 (2), is slidably installed in both sliding grooves (9). Slider 2, which is fixedly connected to mold body 2 (3), is slidably installed in both sliding grooves (10). Screw 1 (13) and screw 2 (14) are fixedly installed at both ends of the rotating rod (12). Screw 1 (13) is threadedly connected to slider 1, and screw 2 (14) is threadedly connected to slider 2. Servo motor (11) is fixedly installed on the side wall of the casting island platform (1). The output end of servo motor (11) is fixedly connected to one end of screw 2 (14). The synchronization component consists of a lead screw three (19), a bevel gear one (20), and a bevel gear two (21). The lead screw three (19) is rotatably installed in one of the moving slots (16), and the lead screw three (19) is threadedly connected to the corresponding moving block (17). The bevel gear one (20) is fixedly installed on the rotating rod (12), and the bevel gear two (21) is fixedly installed on the lead screw three (19), and the bevel gear two (21) meshes with the bevel gear one (20). The lifting assembly consists of a connecting groove, a connecting plate (26), and a lead screw (27). The connecting groove is opened on the support plate (18). The connecting plate (26) is slidably installed in the connecting groove and is fixedly connected to the buffer plate (22). The lead screw (27) is rotatably installed on the support plate (18) and one end of the lead screw (27) located in the connecting groove is threadedly connected to the connecting plate (26). The drive assembly consists of a fixed base (28), a connecting rod (29), a bevel gear three (30), a bevel gear four (31), a fixed gear (32), a groove (33), and a fixed rack (34). The fixed base (28) is fixedly installed at the bottom of the support plate (18). The connecting rod (29) is rotatably installed on the fixed base (28). The bevel gear three (30) is fixedly installed on the connecting rod (29). The bevel gear four (31) is fixedly installed at one end of the lead screw four (27) outside the support plate (18), and the bevel gear four (31) meshes with the bevel gear three (30). The fixed gear (32) is fixedly installed at the other end of the connecting rod (29). The groove (33) is opened on the side wall of the through groove (15), and the groove (33) cooperates with the fixed gear (32). The fixed rack (34) is fixedly installed in the groove (33), and the fixed rack (34) cooperates with the fixed gear (32). The length of the fixed rack (34) is less than or equal to the difference between the width of the through groove (15) and the width of the buffer plate (22).

2. The composite sand casting device for the middle trough of a scraper conveyor according to claim 1, characterized in that, The screw 1 (13) and screw 2 (14) have opposite directions of rotation, and the pitch of screw 1 (13) is smaller than the pitch of screw 2 (14). The support platform (24) is arc-shaped on both sides.

3. A casting method for the middle trough of a scraper conveyor, using a composite sand casting device for the middle trough of a scraper conveyor as described in claim 2, characterized in that, Includes the following steps: S1: Clean the cavity (4) to keep its surface clean and smooth. At the same time, clean the bottom injection port (5) and riser (6) to ensure that they are unobstructed. Start the servo motor (11) to make the mold body one (2) and the mold body two (3) fit together. S2: Select high-quality scrap steel with low sulfur and low phosphorus, and use high-carbon ferromanganese or ferrochrome as smelting material. Bake the alloy material to be used at 200-300℃ for 2-3 hours to remove moisture and volatiles and avoid the generation of porosity during smelting. S3: Use a 10t medium-frequency induction furnace to melt the materials. The order of adding materials is as follows: first add scrap steel, then add recycled materials, and finally add high-carbon ferromanganese, ferrochrome or alloy materials. Avoid adding alloy materials first, which may cause burn-off. After the molten metal is completely melted, raise the temperature to 1500-1550℃ and hold for 30-40 minutes to ensure uniform composition. S4: First, add 0.5% ferrosilicon for pre-deoxidation to the molten liquid, and then add 0.15% aluminum for final deoxidation after 10 minutes to ensure that the oxygen content is ≤0.003%. Then, introduce argon gas at a flow rate of 0.8-1.0 L / min and stir for 15-20 minutes to control the hydrogen content to ≤0.0003% to avoid subcutaneous porosity. Take a sample of the molten liquid before it is removed from the furnace and analyze its composition with a direct-reading spectrometer to ensure that it meets the material standards. If it does not meet the standards, add alloy material to adjust it. S5: Preheat the casting ladle to 800-1000℃, place a φ2mm high-temperature resistant metal filter screen at the inlet of the inlet, preheat the high-strength molding sand layer (8) to 50-80℃, and blow the cavity (4) with compressed air to remove residual sand particles; S6: Pour from the bottom inlet (5) until the cavity (4) is full. Pour the riser (6) 1-2 times, and each time pour 1 / 5 of the riser (6) volume to ensure that the riser (6) continues to shrink and reduce shrinkage cavities. S7: Close the pouring gate and let the casting cool naturally in the high-strength molding sand layer (8). The cooling rate is controlled at ≤30℃ / h to avoid excessive temperature difference and thermal stress. When the casting temperature is cooled to ≤150℃, the servo motor (11) is started in reverse to separate the mold body one (2) and the mold body two (3). During this process, the rotation of the rotating rod (12) drives the screw three (19) to rotate simultaneously through the meshing of the bevel gear one (20) and the bevel gear two (21). The support plate (18) drives the support platform (24) to move on the casting island platform (1) through the buffer plate (22). S8: When the support plate (18) starts to move, the buffer plate (22) drives the support platform (24) to move upward through the cooperation of the drive component and the lifting component. After the mold body one (2) and mold body two (3) are separated, the support platform (24) supports the bottom of the casting in the cavity (4) and moves the casting away from the casting island platform (1) as the support plate (18) moves. At this time, the workers can cut the gating gate of the casting and use the hoisting device or conveyor belt to send the casting into the shot blasting machine for surface treatment. Then the surface-treated casting is put into the heating furnace for heating treatment to ensure that the carbides are completely dissolved. Then it is quickly water quenched to obtain the middle groove of the scraper machine.

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