A sand mixer

Abstract

The application belongs to the technical field of casting equipment and relates to a sand mixer. The sand mixer comprises a sand mixing bin and an extensible conveying mechanism, wherein the extensible conveying mechanism is rotatably installed in the sand mixing bin; the extensible conveying mechanism comprises a plurality of connecting pipes which are sequentially and slidably connected, when the extensible conveying mechanism is elongated, intervals are formed between adjacent connecting pipes, and an auger is rotatably installed in each connecting pipe; and a driving assembly for driving the extensible conveying mechanism to extend or retract is installed on the sand mixing bin. The extensible conveying mechanism is elongated to form annular channels at different heights, and the binder is scattered into the molding sand from the annular channels, thereby avoiding the dust problem during the feeding of the binder. The binder can be simultaneously fed into the molding sand at multiple height layers and multiple circumferential positions, the initial distribution uniformity of the binder in the molding sand is improved, the time required for subsequent mixing is shortened, and the phenomenon of local enrichment or lack is reduced.

Description

Technical Field

[0001] This invention belongs to the field of casting equipment technology and relates to a sand mixer. Background Technology

[0002] Sand mixers are used in the foundry industry to uniformly mix molding sand, binders, and other raw materials to prepare molding sand that meets the requirements of the casting process. However, existing sand mixers generally add binders by directly pouring them from above the mixing bin or through a simple chute. Because the binder is a fine powder with low density and fine particles, when poured directly onto the surface of the molding sand, the high-speed rotation of the mixing paddle easily stirs up the powdery binder during subsequent mixing, creating a large amount of dust.

[0003] Patent CN120347160A discloses a sand mixing machine for foundry molding sand. It uses a feeding paddle inserted into the material to directly inject binder into the material matrix. Deep embedding of the binder is achieved during the circumferential rotation of the feeding assembly around the mixing chamber, thus suppressing dust generation to some extent. However, in this design, the binder is mainly discharged from the trough outlet below the feeding paddle, and the feeding points are concentrated at a single height layer where the feeding paddle is located, making it difficult to simultaneously feed multiple points at different heights within the mixing chamber. This results in limited vertical uniformity of the binder distribution in the molding sand pile, with some areas having higher binder concentrations and others lower concentrations. A longer mixing time is still required to achieve overall uniform mixing, thus affecting the mixing efficiency to some extent.

[0004] To address the above problems, this invention proposes a sand mixer. Summary of the Invention

[0005] To address the problems existing in the background art, the present invention proposes a sand mixer.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: a sand mixer, comprising a sand mixing bin and a telescopic conveying mechanism, wherein the telescopic conveying mechanism is rotatably installed inside the sand mixing bin; the telescopic conveying mechanism comprises a plurality of connecting pipes that are slidably connected in sequence, wherein when the telescopic conveying mechanism extends, a gap appears between adjacent connecting pipes, and an auger is rotatably installed inside the connecting pipes; a drive assembly for driving the telescopic conveying mechanism to extend and retract is installed on the sand mixing bin.

[0007] The telescopic conveyor extends to form a gap, allowing the adhesive to be discharged radially from the gap and directly injected into the molding sand, thus suppressing dust at the source.

[0008] Furthermore, the sand mixing silo is rotatably mounted with a rotating seat, and a fixed frame is fixedly mounted on the rotating seat. The fixed frame is rotatably connected to a connecting shaft. A rotating ring is rotatably mounted on the bottom wall of the sand mixing silo. The lower end of the connecting shaft is rotatably connected to the rotating ring. In the telescopic conveying mechanism, the lowermost connecting pipe is fixedly connected to the rotating ring through a fixed column. The auger is fixedly mounted on the connecting shaft.

[0009] Furthermore, in the telescopic conveying mechanism, the uppermost connecting pipe is fixedly connected to a hopper.

[0010] The hopper is designed to facilitate the addition of adhesive and serves as the feed inlet for the telescopic conveyor mechanism.

[0011] Furthermore, the drive assembly includes a second electric push rod, which is mounted on a rotating base, and the telescopic end of the second electric push rod is connected to the hopper.

[0012] The second electric push rod drives the hopper to rise and fall, thereby causing each connecting pipe to extend and retract in sequence, realizing the automatic control of the telescopic mechanism.

[0013] Furthermore, between two adjacent connecting pipes, the upper end of the lower connecting pipe is provided with a first inclined surface, and the lower end of the upper connecting pipe is provided with a second inclined surface.

[0014] During the overlapping process of the telescopic conveyor mechanism, materials are prevented from being squeezed and piled up between two adjacent connecting pipes, so that the connecting pipes can be successfully overlapped.

[0015] Furthermore, between two adjacent connecting pipes, the upper end of the lower connecting pipe is fixedly connected to a first sliding rod, and the lower end of the upper connecting pipe is provided with a first sliding groove that slides and engages with the first sliding rod; the upper end of the first sliding rod is provided with a shoulder, and the lower end of the first sliding groove is provided with a blocking part that engages with the shoulder; the shoulder is provided with a vent hole, and the first sliding rod and the first sliding groove are in a sealed sliding engagement.

[0016] It enables the expansion and contraction guidance and limiting between connecting pipes, while sealing to prevent material leakage, and the vent hole balances the air pressure.

[0017] Furthermore, a fixed base is fixedly installed on the outer wall of the sand mixing chamber, a first motor is installed on the fixed base, a gear is fixedly connected to the output shaft of the first motor, and a gear ring that meshes with the gear is fixedly connected to the rotating base.

[0018] Furthermore, a discharge port is provided at the lower part of the sand mixing bin, and a baffle that blocks the discharge port is slidably provided on the outer wall of the sand mixing bin; a guide plate is installed on the sand mixing bin at a position corresponding to the discharge port.

[0019] The guide plate facilitates the discharge of the mixed molding sand and directs the discharge direction.

[0020] Furthermore, a first electric push rod is installed on the outer wall of the sand mixing chamber, and the telescopic end of the first electric push rod is fixedly connected to the baffle.

[0021] Furthermore, a rotating groove is provided on the bottom wall of the sand mixing bin, and the rotating ring is rotatably installed in the rotating groove.

[0022] Compared with existing technologies, the present invention has the following advantages: By extending the telescopic conveying mechanism to form annular channels at different heights, the adhesive is sprinkled into the molding sand from the annular channels, avoiding the dust problem during adhesive feeding. The adhesive can be simultaneously added into the molding sand at multiple height layers and multiple circumferential positions, improving the initial uniformity of the adhesive distribution in the molding sand, shortening the time required for subsequent mixing, and reducing the phenomenon of local enrichment or absence.

[0023] The auger allows the molding sand from the upper layer to the lower layer, creating a circulating flow that ensures the binder and molding sand are fully mixed, improving the uniformity of the mixture. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a schematic diagram of the internal structure of the sand mixing silo in this invention; Figure 3 This is a cross-sectional view of the telescopic conveying mechanism in this invention; Figure 4 In this invention Figure 3 Enlarged view of part A; Figure 5 This is a schematic diagram of the connecting pipe in this invention; Figure 6 This is a simplified schematic diagram of the flow of molding sand during stirring in this invention.

[0025] In the diagram: 1. Mixing bin; 2. Fixed base; 3. First motor; 4. Gear; 5. First electric push rod; 6. Baffle; 7. Guide plate; 8. Rotating seat; 9. Gear ring; 10. Second electric push rod; 11. Fixed plate; 12. Hopper; 13. First chute; 14. First slide rod; 15. Connecting pipe; 16. First inclined plane; 17. Rotating groove; 18. Fixed column; 19. Fixed frame; 20. Second motor; 21. Connecting shaft; 22. Screwdriver; 23. Rotating ring. Detailed Implementation

[0026] 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.

[0027] like Figures 1-6 As shown, the technical solution adopted by the present invention is as follows: a sand mixer includes a sand mixing bin 1 and a telescopic conveying mechanism.

[0028] The telescopic conveying mechanism is rotatably installed inside the sand mixing silo 1. A rotating seat 8 is rotatably installed on the top of the sand mixing silo 1, and a rotating groove 17 is opened on the bottom wall of the sand mixing silo 1. A rotating ring 23 is rotatably installed in the rotating groove 17. A fixing frame 19 is fixedly installed on the rotating seat 8, and a connecting shaft 21 is rotatably connected to the fixing frame 19. The lower end of the connecting shaft 21 is rotatably connected to the rotating ring 23.

[0029] A second motor 20 is fixedly installed on the fixed frame 19, and the output shaft of the second motor 20 is fixedly connected to the upper end of the connecting shaft 21.

[0030] The telescopic conveying mechanism includes multiple connecting pipes 15 that are slidably connected in sequence. The lowermost connecting pipe 15 is fixedly connected to the rotating ring 23 via a fixed column 18, and the uppermost connecting pipe 15 is fixedly connected to a hopper 12. The hopper 12 slides through the rotating seat 8. The connecting shaft 21 is coaxially arranged with the connecting pipes 15. An auger 22 is rotatably installed inside the multiple connecting pipes 15, and the auger 22 is fixedly installed on the connecting shaft 21.

[0031] To enable the extension and retraction of the telescopic conveyor mechanism, a drive assembly is installed on the sand mixing bin 1. For example... Figure 1 As shown, specifically, the drive assembly includes a second electric push rod 10, which is mounted on the rotating base 8. The telescopic end of the second electric push rod 10 is fixedly connected to the hopper 12 via a fixing plate 11. When the second electric push rod 10 pushes the hopper 12 upward, the connecting pipes 15 separate sequentially, creating gaps between adjacent connecting pipes 15. This allows the adhesive within the telescopic conveying mechanism to flow out through the gaps between adjacent connecting pipes 15.

[0032] The drive assembly can also use a cylinder, hydraulic cylinder or screw lifting mechanism to drive the hopper 12 to lift and lower, achieving the same telescopic control effect of the telescopic conveying mechanism.

[0033] In this embodiment, as Figure 3 , Figure 4 as well as Figure 5As shown, between two adjacent connecting pipes 15, the upper end of the lower connecting pipe 15 is fixedly connected to a first sliding rod 14, and the lower end of the upper connecting pipe 15 is provided with a first sliding groove 13 that slides and engages with the first sliding rod 14. The upper end of the first sliding rod 14 is provided with a shoulder, and the lower end of the first sliding groove 13 is provided with a blocking part that engages with the shoulder to prevent the first sliding rod 14 from disengaging from the first sliding groove 13.

[0034] The first slide bar 14 and the blocking part of the first slide groove 13 are sealed and slide together. At the same time, a vent is provided on the shoulder, which can ensure the balance of airflow and prevent material from entering the first slide groove 13.

[0035] Between two adjacent connecting pipes 15, the upper end of the lower connecting pipe 15 is provided with a first inclined surface 16, the outer side of which slopes downward. The lower end of the upper connecting pipe 15 is provided with a second inclined surface, the outer side of which slopes upward. The provision of the first inclined surface 16 and the second inclined surface helps to prevent material from being squeezed and accumulated between the two connecting pipes 15, and facilitates the smooth overlapping of the two adjacent connecting pipes 15.

[0036] To enable the telescopic conveyor mechanism to rotate and spread material within the sand mixing bin 1, a fixed base 2 is fixedly installed on the outer wall of the sand mixing bin 1. A first motor 3 is mounted on the fixed base 2, and a gear 4 is fixedly connected to the output shaft of the first motor 3. A gear ring 9 that meshes with the gear 4 is fixedly connected to the outer periphery of the rotating base 8. When the first motor 3 starts, the gear 4 drives the gear ring 9 and the rotating base 8 to rotate as a whole, thereby driving the entire telescopic conveyor mechanism and the hopper 12 to rotate around the axis of the sand mixing bin 1 within the sand mixing bin 1.

[0037] To facilitate material discharge, a discharge port is provided at the bottom of the sand mixing bin 1, and a guide plate 7 is installed on the sand mixing bin 1 at the corresponding position of the discharge port. A baffle 6 is slidably provided on the outer wall of the sand mixing bin 1 to block the discharge port, and a first electric push rod 5 is also installed on the fixed base 2. The telescopic end of the first electric push rod 5 is fixedly connected to the baffle 6 for automatically controlling the opening and closing of the discharge port.

[0038] Working principle: Initially, each connecting pipe 15 is in an overlapping state, that is, adjacent connecting pipes 15 are in contact with each other.

[0039] First, the adhesive (such as bentonite, coal powder, etc.) is put into the hopper 12. The second motor 20 is started, which drives the connecting shaft 21 and the auger 22 to rotate, so that the adhesive is conveyed downward along the hopper 12 and each connecting pipe 15 until the entire telescopic conveying mechanism is filled with adhesive.

[0040] Next, the second electric push rod 10 is activated, pushing the hopper 12 upward. Due to the sliding engagement between the first slide rod 14 and the first slide groove 13, and the limiting effect of the shoulder and the blocking part, the uppermost connecting pipe 15 is lifted first by the hopper 12, separating it from the connecting pipe 15 below. As it continues to move upward, the lower connecting pipes 15 are lifted in sequence until all connecting pipes 15 are separated from each other, forming annular channels between adjacent connecting pipes 15. These annular channels are distributed vertically at different height levels.

[0041] Then, the first motor 3 and the second motor 20 are started. The first motor 3 drives the rotating seat 8, the telescopic conveying mechanism, and the hopper 12 to rotate as a whole through the gear 4 and the gear ring 9. When the telescopic conveying mechanism rotates, the connecting pipe 15 disturbs and pushes the surrounding molding sand, creating local gaps near the outlet of the annular channel. After the adhesive flows out from each annular channel, it is immediately buried and wrapped by the surrounding molding sand, avoiding the process of being exposed on the surface and then stirred up, thus suppressing dust. Since each annular channel is distributed at different heights, the adhesive is simultaneously injected into the molding sand at multiple levels and points. At the same time, the second motor 20 drives the connecting shaft 21 and the auger 22 to rotate, conveying the molding sand in the upper layer of the mixing bin 1 downwards, forming an up-and-down circulating flow. Specifically, as shown... Figure 6 As shown, molding sand enters the connecting pipe 15 from one side of the annular channel and is conveyed downwards by the auger 22. The molding sand in the connecting pipe 15 is discharged from the other side of the annular channel, forming an up-and-down circulating flow. The revolution of the telescopic conveying mechanism, the multi-layer annular channel, and the rotation of the auger 22 not only improve the uniformity of the adhesive distribution in the molding sand, but also increase the mixing speed of the adhesive and molding sand.

[0042] When the telescopic conveyor mechanism needs to be reset, the second electric push rod 10 drives the hopper 12 downward, sequentially pushing each connecting pipe 15 downward to overlap until all connecting pipes 15 are restored to their overlapping state. Then, the second motor 20 is restarted, causing the auger 22 to rotate, conveying the molding sand remaining in the hopper 12 and connecting pipes 15 downward, and discharging it through the gaps between the fixed columns 18 into the mixing chamber 1. During the reset of the telescopic conveyor mechanism, the design of the first inclined surface 16 and the second inclined surface prevents material from being squeezed and accumulated in the annular channel, facilitating the smooth overlapping of the connecting pipes 15.

[0043] Finally, the discharge port is opened by driving the baffle 6 through the first electric push rod 5, and the mixed molding sand is discharged through the guide plate 7.

[0044] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A sand mixer, characterized in that: The system includes a sand mixing bin (1) and a telescopic conveying mechanism, the telescopic conveying mechanism being rotatably installed inside the sand mixing bin (1); the telescopic conveying mechanism includes a plurality of connecting pipes (15) that are slidably connected in sequence, and when the telescopic conveying mechanism extends, there is a gap between adjacent connecting pipes (15), and an auger (22) is rotatably installed inside the connecting pipes (15); a drive assembly for driving the telescopic conveying mechanism to extend and retract is installed on the sand mixing bin (1); The sand mixing silo (1) is rotatably mounted with a rotating seat (8), and a fixed frame (19) is fixedly mounted on the rotating seat (8). The fixed frame (19) is rotatably connected to a connecting shaft (21). A rotating ring (23) is rotatably mounted on the bottom wall of the sand mixing silo (1). The lower end of the connecting shaft (21) is rotatably connected to the rotating ring (23). In the telescopic conveying mechanism, the lowermost connecting pipe (15) is fixedly connected to the rotating ring (23) through a fixed column (18). The auger (22) is fixedly mounted on the connecting shaft (21). A second motor (20) is fixedly mounted on the fixed frame (19). The output shaft of the second motor (20) is fixedly connected to the upper end of the connecting shaft (21). The connecting shaft (21) and the connecting pipe (15) are coaxially arranged. In the telescopic conveying mechanism, the uppermost connecting pipe (15) is fixedly connected to the hopper (12), and the hopper (12) slides through the rotating seat (8); the lowermost connecting pipe (15) is fixedly connected to the rotating ring (23) through the fixed column (18); The drive assembly includes a second electric push rod (10), which is mounted on a rotating seat (8). The telescopic end of the second electric push rod (10) is fixedly connected to the hopper (12) through a fixing plate (11). Between two adjacent connecting pipes (15), the upper end of the lower connecting pipe (15) is provided with a first inclined surface (16), and the lower end of the upper connecting pipe (15) is provided with a second inclined surface; the outer side of the first inclined surface (16) slopes downward, and the outer side of the second inclined surface slopes upward. Between two adjacent connecting pipes (15), the upper end of the lower connecting pipe (15) is fixedly connected to a first sliding rod (14), and the lower end of the upper connecting pipe (15) is provided with a first sliding groove (13) that slides and engages with the first sliding rod (14); the upper end of the first sliding rod (14) is provided with a shoulder, and the lower end of the first sliding groove (13) is provided with a blocking part that engages with the shoulder, and a vent hole is provided on the shoulder; the first sliding rod (14) and the blocking part of the first sliding groove (13) are in a sealed sliding fit; A fixed seat (2) is fixedly installed on the outer wall of the sand mixing silo (1). A first motor (3) is installed on the fixed seat (2). A gear (4) is fixedly connected to the output shaft of the first motor (3). A gear ring (9) that meshes with the gear (4) is fixedly connected to the rotating seat (8).

2. A sand mixer according to claim 1, characterized in that: The lower part of the sand mixing bin (1) is provided with a discharge port, and a baffle (6) is slidably provided on the outer side wall of the sand mixing bin (1) to block the discharge port; a guide plate (7) is installed on the sand mixing bin (1) at the position corresponding to the discharge port.

3. A sand mixer according to claim 2, characterized in that: A first electric push rod (5) is installed on the outer wall of the sand mixing bin (1), and the telescopic end of the first electric push rod (5) is fixedly connected to the baffle (6).

4. A sand mixer according to claim 1, characterized in that: A rotating groove (17) is provided on the bottom wall of the sand mixing silo (1), and the rotating ring (23) is rotatably installed in the rotating groove (17).

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