A secondary screening device for sweet potato after harvesting

Abstract

The application discloses a secondary screening device for sweet potato after harvesting, which comprises a mounting frame, a discharging mechanism is installed on one side of the top of the mounting frame, a flexible guide cover is installed at the bottom output end of the discharging mechanism, an inclined first-stage screening mechanism is connected to the output end of the flexible guide cover, a plurality of elastic suspension assemblies are installed on the two sides of the first-stage screening mechanism, the top of the elastic suspension assembly is installed on the mounting frame, elastic support assemblies are installed on the bottom two sides of the first-stage screening mechanism, the elastic support assemblies are installed on the two sides of the mounting frame, a material outlet and an impurity outlet are arranged on the bottom side of the first-stage screening mechanism, the impurity outlet is arranged on the front side of the material outlet, a flexible guide channel is connected to the output end of the material outlet, a second-stage screening mechanism is arranged at the output end of the flexible guide channel, an impurity collecting frame is installed at the bottom of the second-stage screening mechanism, an impurity guide sleeve is installed at the output end of the impurity outlet, and the output end of the impurity guide sleeve is arranged on the upper side of the impurity collecting frame.

Description

Technical Field

[0001] This invention belongs to the field of sweet potato screening technology, specifically relating to a secondary screening device for sweet potatoes after harvest. Background Technology

[0002] Sweet potato, also known as yam, sweet potato, or white potato, is a common root vegetable and grain crop. As an important food and economic crop in my country, sweet potato has a wide planting area and high total yield, playing a vital role in ensuring food security and supporting rural industrial development. With the increasing scale of sweet potato planting, mechanized harvesting has become the mainstream method. However, sweet potatoes harvested by combine harvesters generally contain a large amount of impurities, including fine soil, clumps of soil, small stones, sweet potato vine residue, vine fragments, broken tubers, and defective tubers, resulting in extremely high material impurity. It is necessary to screen and grade the material before it can enter storage, processing, or distribution. However, existing screening devices have limited functionality and low integration. Traditional screening devices can only perform simple surface cleaning or coarse particle size screening and grading. They cannot simultaneously perform fine cleaning operations and are unable to completely remove various impurities such as fine soil, gravel, and vine residue from sweet potato tubers. The overall screening efficiency is low. Furthermore, traditional screening devices lack active anti-clogging and self-cleaning structures. Impurities such as damp soil clods, flexible sweet potato vine fibers, and fine vine residue contained in the harvested sweet potato material are easily embedded in the screen holes due to material compression and adhesion during the screening process, causing screen blockage. After the screen holes are blocked, the machine must be stopped for manual cleaning, which cannot achieve continuous and uninterrupted operation. Frequent shutdowns for cleaning significantly disrupt the production line's operating rhythm and greatly reduce the continuity and stability of sweet potato screening operations. Summary of the Invention

[0003] In view of the problems mentioned in the background art above, the purpose of the present invention is to provide a secondary screening device for sweet potatoes after harvest.

[0004] To achieve the above-mentioned technical objectives, the technical solution adopted by the present invention is as follows: A secondary screening device for sweet potatoes after harvest includes a mounting frame. A feeding mechanism is mounted on one side of the top of the mounting frame. A flexible guide cover is mounted on the bottom output end of the feeding mechanism. The output end of the flexible guide cover is connected to a primary screening mechanism with an inclined structure. Several elastic suspension components are mounted on both sides of the primary screening mechanism. The tops of the elastic suspension components are mounted on the mounting frame. Elastic support components are mounted on both sides of the bottom of the primary screening mechanism. The elastic support components are mounted on both sides of the mounting frame. A material outlet and an impurity outlet are provided on the bottom side of the primary screening mechanism. The impurity outlet is located in front of the material outlet. The output end of the material outlet is connected to a flexible guide channel. A secondary screening mechanism is provided at the output end of the flexible guide channel. An impurity collection frame is mounted on the bottom of the secondary screening mechanism on the mounting frame. An impurity guide sleeve is mounted on the output end of the impurity outlet. The output end of the impurity guide sleeve is located above the impurity collection frame.

[0005] Further specifying, the feeding mechanism includes a support frame, within which a feeding channel is installed. A feeding guide cover is installed at the top of the feeding channel, and the bottom output end of the feeding channel is connected to the input end of the flexible guide cover. Several evenly arranged rotating shafts are rotatably mounted on both sides of the feeding channel, with a flow channel between the two rotating shafts. A mounting assembly is installed on each rotating shaft, and several evenly arranged strip-shaped brushes are mounted on the assembly. A drive motor is installed on one side of the support frame, and the power output end of the drive motor is connected to one of the rotating shafts. Several transverse transmission components are installed on the side of the feeding channel away from the drive motor, and these transverse transmission components are installed between two transversely arranged rotating shafts. Several vertical transmission components are installed on the side of the feeding channel opposite the drive motor, and these vertical transmission components are installed between two vertically arranged rotating shafts. This structural design facilitates cleaning the sweet potatoes during the feeding process.

[0006] Furthermore, the horizontal transmission assembly and the vertical transmission assembly are identical in size and shape. The horizontal transmission assembly includes two transmission wheels and a transmission belt. The two transmission wheels are respectively mounted on a rotating shaft, and the transmission belt is disposed between the two transmission wheels. This structural design facilitates the rotation of multiple rotating shafts.

[0007] Further specifying, the primary screening mechanism includes a primary screen frame, a vibrating motor installed at the bottom of the primary screen frame, a feed inlet on one side of the top of the primary screen frame, an output end of the flexible guide cover installed inside the feed inlet, and a material outlet and an impurity outlet located at the bottommost side of the primary screen frame. The primary screen frame contains several evenly arranged flexible grid bars, with screen gaps between adjacent flexible grid bars. This structural design facilitates primary screening of sweet potatoes.

[0008] Furthermore, the flexible grid strip includes a metal core, and a flexible wear-resistant layer is provided on the outer side of the metal core. This structural design can reduce rigid impacts and lower the breakage rate of sweet potatoes.

[0009] Further specifying, the elastic suspension assembly includes a locking seat mounted on the primary screen frame, a first spring seat hinged to the outer side of the locking seat, a first spring mounted on the top of the first spring seat, a second spring seat mounted on the free end of the top of the first spring, and a suspension seat hinged to the top of the second spring seat, the suspension seat being mounted on a mounting frame. This structural design allows for the elastic suspension of the primary screening mechanism.

[0010] Further specifying, the elastic support assembly includes support plates mounted on both sides of the mounting frame. Reinforcing ribs are provided at the connection points between the support plates and the mounting frame on both sides. Several evenly arranged mounting plates are mounted on the support plates. A second spring is mounted on each mounting plate. A support seat is mounted on the top free end of the second spring. The top of the support seat is mounted on the bottom of the primary screen frame. A guide groove is provided on the lower side inside the support seat. A third spring is mounted within the guide groove. A guide post is mounted on the bottom free end of the third spring. The bottom of the guide post is mounted on the mounting plate. This structural design provides elastic support for the primary screening mechanism.

[0011] Further specifying, the secondary screening mechanism includes a fine screening motor. The mounting frame has a motor base corresponding to the fine screening motor, which is mounted on the motor base. A rotating disk is mounted on the power output end of the fine screening motor. An eccentric column is mounted on one side of the rotating disk, and a connecting rod is hinged to the eccentric column. A connecting seat is hinged to the other side of the connecting rod, and a secondary screening frame is mounted on the other side of the connecting seat. The bottom of the secondary screening frame has several evenly arranged screen holes. A guide outlet is located on the side of the secondary screening frame away from the connecting seat. The bottom of the guide outlet has an inclined guide surface. Several evenly arranged pulleys are mounted on both sides of the secondary screening frame. Guide seats are mounted on both sides of the bottom of the mounting frame. The pulleys are slidably positioned on the top of the guide seats. Several evenly arranged cleaning components are installed between the two guide seats. This structural design allows for secondary screening of sweet potatoes.

[0012] Further specifying, the cleaning assembly includes several rotating shafts rotatably mounted between the guide seats on both sides. A cleaning sleeve is mounted on the surface of each rotating shaft, and the surface of each cleaning sleeve is provided with several evenly arranged cleaning bristles, which are located at the bottom of the secondary screen frame. This structural design facilitates the cleaning of the secondary screen frame and prevents clogging of the screen holes.

[0013] Further specifying, the output end of the flexible guide channel is externally mounted with a fixed base, which is installed on the top of the secondary sieve frame. Diversion channels are provided on both sides of the bottom of the impurity guide sleeve. The flexible guide channel and connecting rod are movably disposed between the two diversion channels. The bottom output end of the diversion channel is located on the upper side of the impurity collection frame. Diversion guide protrusions are provided inside the impurity guide sleeve between the two diversion channels. This structural design guides the sweet potato through the flexible guide channel and guides the impurities after primary sieving through the impurity guide sleeve.

[0014] The beneficial effects of this invention are as follows: 1. This invention integrates three processes—surface cleaning, primary screening, and secondary screening—into a continuous operation system. After the material enters the feeding channel, the circumferentially rotating strip brush continuously rubs the surface of the potato tuber as it slides down under its own weight, simultaneously completing the initial cleaning of surface soil and residual leaves. Subsequently, the primary vibrating screen removes large-particle impurities such as soil, gravel, and broken potato tubers, and the secondary reciprocating screen removes attached fine impurities. The multiple impurity removal processes are seamlessly connected, which can thoroughly remove various impurities such as fine soil, clumps of soil, gravel, vine debris, and defective potato tubers mixed in with the potato tubers, significantly improving screening cleanliness and overall operation efficiency.

[0015] 2. This invention features a cleaning component at the bottom of the secondary screening mechanism. When the secondary screen frame reciprocates during screening, its bottom surface rubs against the cleaning brush bristles, causing the rotating shaft to rotate synchronously. This allows the cleaning brush bristles to continuously sweep across the screen holes and extend into them, automatically removing embedded dirt, debris, and other impurities. This maintains the screen holes' permeability without requiring manual intervention to stop the machine, fundamentally preventing the problem of damp soil, vine residue, and other impurities clogging the screen holes. This ensures continuous and uninterrupted operation of the production line and improves the continuity and operational stability of sweet potato screening.

[0016] 3. This invention simplifies the production process. After the impurities separated by the first-stage screening are discharged through the impurity outlet, they are guided to the impurity collection frame by the impurity guide sleeve. The fine impurities falling from the second-stage screening fall directly into the impurity collection frame below, realizing the unified centralized collection of impurities from both stages of screening without the need for separate cleaning and collection. This simplifies the on-site impurity handling process and is suitable for the continuous screening and processing needs after large-scale sweet potato planting and harvesting. Attached Figure Description

[0017] The present invention can be further illustrated by the non-limiting embodiments given in the accompanying drawings; Figure 1 This is a schematic diagram of the axial side structure of a secondary screening device for sweet potatoes after harvest, according to an embodiment of the present invention. Figure 2 This is a cross-sectional structural diagram of a secondary screening device for sweet potatoes after harvest, according to an embodiment of the present invention. Figure 3 This is a schematic cross-sectional view of the feeding mechanism of a secondary screening device for sweet potatoes after harvest, according to an embodiment of the present invention. Figure 4 This is a schematic cross-sectional view of an impurity guide sleeve for a secondary screening device after sweet potato harvest, according to an embodiment of the present invention. Figure 5 This is a schematic diagram of the cross-sectional structure of a flexible grid bar for a secondary screening device after sweet potato harvest, according to an embodiment of the present invention. Figure 6 This is an enlarged structural diagram of point A of a secondary screening device for sweet potatoes after harvest, according to an embodiment of the present invention. Figure 7 This is an enlarged structural diagram of section B of a secondary screening device for sweet potatoes after harvest, according to an embodiment of the present invention. Figure 8 This is an enlarged structural diagram of point C of a secondary screening device for sweet potatoes after harvest, according to an embodiment of the present invention. The symbols for the main components are explained below: 1. Mounting frame; 2. Feeding mechanism; 3. Flexible guide cover; 4. Primary screening mechanism; 5. Elastic suspension assembly; 6. Elastic support assembly; 7. Material outlet; 8. Impurity outlet; 9. Flexible guide channel; 10. Secondary screening mechanism; 11. Impurity collection frame; 12. Impurity guide sleeve; 13. Support frame; 14. Feeding channel; 15. Feeding guide cover; 16. Rotating shaft; 17. Flow channel; 18. Assembly kit; 19. Strip brush; 20. Drive motor; 21. Horizontal transmission assembly; 22. Vertical transmission assembly; 23. Transmission wheel; 24. Transmission belt; 25. Primary screen frame; 26. Vibrating motor; 27. Feed inlet; 28. Flexible grid; 29. ​​Screen gap; 30. Metal core; Wear-resistant layer 31, lock seat 32, first spring seat 33, first spring 34, second spring seat 35, suspension seat 36, support plate 37, reinforcing rib 38, mounting plate 39, second spring 40, support seat 41, guide groove 42, third spring 43, guide column 44, fine screening motor 45, motor seat 46, rotating disk 47, eccentric column 48, connecting rod 49, connecting seat 50, secondary screen frame 51, screen hole 52, guide output port 53, guide surface 54, pulley 55, guide seat 56, cleaning assembly 57, rotating shaft 58, cleaning sleeve 59, cleaning brush bristles 60, fixed seat 61, diversion channel 62, diversion guide protrusion 63. Detailed Implementation

[0018] To enable those skilled in the art to better understand the present invention, the technical solution of the present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0019] Example 1, such as Figure 1 and Figure 2As shown, a secondary screening device for sweet potatoes after harvesting includes a feeding mechanism 2 installed on one side of the top of a mounting frame 1. A flexible guide cover 3 is installed at the bottom output end of the feeding mechanism 2. The output end of the flexible guide cover 3 is connected to a primary screening mechanism 4 with an inclined structure. Several elastic suspension components 5 are installed on both sides of the primary screening mechanism 4. The tops of the elastic suspension components 5 are installed on the mounting frame 1. Elastic support components 6 are installed on both sides of the bottom of the primary screening mechanism 4. The elastic support components 6 are installed on both sides of the mounting frame 1. The bottom side of the primary screening mechanism 4 is provided with a material outlet 7 and an impurity outlet 8. The impurity outlet 8 is located in front of the material outlet 7. The output end of the material outlet 7 is connected to a flexible guide channel 9. The output end of the flexible guide channel 9 is provided with a secondary screening mechanism 10. An impurity collection frame 11 is installed at the bottom of the secondary screening mechanism 10 on the mounting frame 1. An impurity guide sleeve 12 is installed at the output end of the impurity outlet 8. The output end of the impurity guide sleeve 12 is located above the impurity collection frame 11.

[0020] In this embodiment, during use, the harvested sweet potatoes are first fed into the feeding mechanism 2 at the top of the mounting frame 1. The feeding mechanism 2 buffers and guides the sweet potatoes and cleans their surface, ensuring a stable transport to the bottom output end. After being flexibly guided by the flexible guide cover 3, the material enters the primary screening mechanism 4, which is arranged in an inclined structure. The primary screening mechanism 4 is suspended from the mounting frame 1 by several elastic suspension components 5 on both sides, while the bottom sides are provided with elastic support components 6. Under the action of the screening excitation force, the primary screening mechanism 4 generates continuous vibration. Under the combined action of its own weight and the vibration force, the sweet potatoes move along the inclined screen surface to the bottom. During the movement, the vibration screening ensures that the whole sweet potatoes remain on the screen surface and are finally discharged from the bottom of the primary screening mechanism 4. The material outlet 7 discharges the sweet potatoes, while smaller impurities such as soil, leaves, and broken sweet potato pieces pass through the screen surface and are discharged from the impurity outlet 8 located in front of the material outlet 7. The sweet potatoes after primary screening flow out of the material outlet 7 and are smoothly guided and transported to the secondary screening mechanism 10 through the flexible guide channel 9. The secondary screening mechanism 10 performs secondary screening on the sweet potatoes, shaking off the fine impurities on the surface of the sweet potatoes. The fine impurities fall directly into the impurity collection frame 11 on the mounting frame 1 below. The finished sweet potatoes after screening are output and collected from the discharge end of the secondary screening mechanism 10. The impurities separated by primary screening are discharged from the impurity outlet 8 and guided by the impurity guide sleeve 12, and finally fall into the impurity collection frame 11 for unified collection, realizing the centralized collection of impurities from two stages of screening and completing the entire secondary screening process after the sweet potato harvest.

[0021] Example 2, as Figure 1 , Figure 2 , Figure 3 and Figure 4As shown, this embodiment adds the following structure based on embodiment 1: the feeding mechanism 2 includes a support frame 13, a feeding channel 14 is installed inside the support frame 13, a feeding guide cover 15 is installed on the top of the feeding channel 14, the bottom output end of the feeding channel 14 is connected to the input end of the flexible guide cover 3, several evenly arranged rotating shafts 16 are rotatably installed on both sides inside the feeding channel 14, a flow channel 17 is provided between the two rotating shafts 16, a mounting set 18 is installed on the rotating shaft 16, several evenly arranged strip brushes 19 are installed on the mounting set 18, a drive motor 20 is installed on one side of the support frame 13, the power output end of the drive motor 20 is connected to one of the rotating shafts 16, several horizontal transmission components 21 are installed on the side of the feeding channel 14 away from the drive motor 20, the several horizontal transmission components 21 are installed between two horizontally arranged rotating shafts 16, several vertical transmission components 22 are installed on the side of the feeding channel 14 away from the drive motor 20, the several vertical transmission components 22 are installed between two vertically arranged rotating shafts 16.

[0022] In this embodiment, sweet potatoes are introduced into the feeding channel 14 via the feeding guide cover 15. After the drive motor 20 starts, it drives the single rotating shaft 16 connected to it to rotate. The power is transmitted step by step through the horizontal transmission component 21 and the vertical transmission component 22, so that all the rotating shafts 16 in the feeding channel 14 rotate synchronously. The rotating shaft 16 drives the strip brush 19 to rotate circumferentially through the fitting 18. As the sweet potato slides down the flow channel 17 enclosed by the rotating shafts 16 on both sides, the rotating strip brush 19 continuously contacts and rubs against the surface of the sweet potato, brushing away the dirt, residual leaves and other impurities attached to the surface. The cleaned sweet potato enters the flexible guide cover 3 from the bottom output end of the feeding channel 14, so that the surface cleaning of the sweet potato can be completed at the same time as feeding and conveying.

[0023] Example 3, as Figure 1 , Figure 3 and Figure 4 As shown, this embodiment adds the following structure based on embodiment 2: the horizontal transmission component 21 and the vertical transmission component 22 are the same in size, structure and shape. The horizontal transmission component 21 includes two transmission wheels 23 and a transmission belt 24. The two transmission wheels 23 are respectively mounted on the rotating shaft 16, and the transmission belt 24 is disposed between the two transmission wheels 23.

[0024] In this embodiment, when the drive motor 20 drives a single rotating shaft 16 to rotate, the rotating shaft 16 drives the transmission wheel 23 on it to rotate synchronously. The transmission wheel 23 drives the transmission wheel 23 on the adjacent horizontally arranged rotating shaft 16 to rotate through the transmission belt 24, thereby realizing the power transmission of the horizontal rotating shaft 16. The vertical transmission component 22 adopts the same transmission wheel 23 and transmission belt 24 cooperation structure to complete the power transmission between vertically adjacent rotating shafts 16, so that all rotating shafts 16 in the feeding channel 14 keep rotating synchronously in the same direction.

[0025] Example 4, as Figure 2 , Figure 4 and Figure 5 As shown, this embodiment adds the following structure based on embodiment 1: the primary screening mechanism 4 includes a primary screen frame 25, a vibration motor 26 is installed at the bottom of the primary screen frame 25, a feed inlet 27 is provided on one side of the top of the primary screen frame 25, the output end of the flexible guide cover 3 is installed in the feed inlet 27, the material outlet 7 and the impurity outlet 8 are located at the bottommost side of the primary screen frame 25, and a number of evenly arranged flexible grid bars 28 are provided inside the primary screen frame 25, with a screen gap 29 between two adjacent flexible grid bars 28.

[0026] In this embodiment, the sweet potatoes conveyed by the flexible guide cover 3 enter the interior of the primary screen frame 25 through the feed inlet 27. After the vibration motor 26 is started, it drives the primary screen frame 25 to generate high-frequency vibration. Under the action of vibration force and its own gravity, the sweet potatoes slide to the bottom side along the inclined primary screen frame 25. During the sliding process, impurities such as soil, small stones, and broken sweet potatoes with a volume smaller than the screen gap 29 fall from the screen gap 29 between the flexible grid bars 28. The larger whole sweet potatoes continue to move to the lower position. Finally, the whole sweet potatoes are discharged from the material outlet 7, and the separated impurities are discharged from the impurity outlet 8.

[0027] Example 5, as Figure 5 As shown, this embodiment adds the following structure to the embodiment 4: the flexible grid 28 includes a metal core 30, and a flexible wear-resistant layer 31 is provided on the outside of the metal core 30.

[0028] In this embodiment, when the sweet potato vibrates and slides within the primary sieve frame 25, it directly contacts the flexible wear-resistant layer 31 on the outer side of the flexible grid bar 28. The internal metal core 30 provides structural support for the flexible grid bar 28, maintaining the stability of the gap size of the sieve slot 29. When the sweet potato collides with the flexible grid bar 28, the flexible wear-resistant layer 31 undergoes elastic deformation to absorb the impact energy, preventing the sweet potato from directly impacting the rigid structure. The metal core 30 ensures that the grid bar will not undergo plastic deformation due to long-term stress.

[0029] Example 6, as Figure 6 As shown, this embodiment adds the following structure based on embodiment 1: the elastic suspension assembly 5 includes a locking seat 32 mounted on the primary screen frame 25, a first spring seat 33 hinged to the outer side of the locking seat 32, a first spring 34 mounted on the top of the first spring seat 33, a second spring seat 35 mounted on the free end of the top of the first spring 34, and a suspension seat 36 hinged to the top of the second spring seat 35. The suspension seat 36 is mounted on the mounting frame 1.

[0030] In this embodiment, the primary screen frame 25 is hinged to the first spring seat 33 via the locking seat 32. The first spring 34 is installed between the first spring seat 33 and the second spring seat 35. The second spring seat 35 is fixed to the mounting frame 1 via the suspension seat 36. When the vibration motor 26 drives the primary screen frame 25 to vibrate, the first spring 34 reciprocates and expands with the vibration of the primary screen frame 25, ensuring the vibration amplitude of the primary screen frame 25 and guaranteeing the screening effect.

[0031] Example 7, as Figure 7 As shown, this embodiment adds the following structure based on embodiment 1: the elastic support assembly 6 includes support plates 37 installed on both sides of the mounting frame 1, reinforcing ribs 38 are provided at the connection between the support plates 37 and the mounting frame 1, a plurality of evenly arranged mounting plates 39 are installed on the support plates 37, a second spring 40 is installed on the mounting plates 39, a support seat 41 is installed at the top free end of the second spring 40, the top of the support seat 41 is installed at the bottom of the primary screen frame 25, a guide groove 42 is provided on the lower side inside the support seat 41, a third spring 43 is installed in the guide groove 42, a guide post 44 is installed at the bottom free end of the third spring 43, and the bottom of the guide post 44 is installed on the mounting plate 39.

[0032] In this embodiment, the support plate 37 is reinforced and installed on both sides of the mounting frame 1 by the reinforcing ribs 38, and the mounting plate 39 is fixed on the support plate 37. The second spring 40, together with the support seat 41, forms a vertical elastic support for the bottom of the primary screen frame 25. When the primary screen frame 25 vibrates, the second spring 40 undergoes elastic deformation with the up and down vibration of the screen frame, providing the main buffer support force. At the same time, the guide column 44 slides back and forth in the guide groove 42 of the support seat 41, and the third spring 43 assists in providing buffer force. The cooperation between the guide column 44 and the guide groove 42 constrains the vibration direction. Through the first spring 34, the second spring 40 and the third spring 43, a multi-level elastic buffer is formed, which further improves the vibration reduction effect of the primary screening mechanism 4 and improves the stability and uniformity of the screening process.

[0033] Example 8, as Figure 1 and Figure 2As shown, this embodiment adds the following structure based on embodiment 1: the secondary screening mechanism 10 includes a fine screening motor 45, a mounting frame 1 with a motor base 46 corresponding to the fine screening motor 45, the fine screening motor 45 is mounted on the motor base 46, a rotating disk 47 is mounted on the power output end of the fine screening motor 45, an eccentric column 48 is mounted on one side of the rotating disk 47, a connecting rod 49 is hinged to the eccentric column 48, a connecting seat 50 is hinged to the other side of the connecting rod 49, a secondary screen frame 51 is mounted on the other side of the connecting seat 50, a plurality of evenly arranged screen holes 52 are provided at the bottom of the secondary screen frame 51, a guide output port 53 is provided on the side of the secondary screen frame 51 away from the connecting seat 50, an inclined guide surface 54 is provided at the bottom of the output end of the guide output port 53, a plurality of evenly arranged pulleys 55 are mounted on both sides of the secondary screen frame 51, guide seats 56 are mounted on both sides of the bottom of the mounting frame 1, the pulleys 55 are slidably mounted on the top of the guide seats 56, and a plurality of evenly arranged cleaning components 57 are installed between the two guide seats 56.

[0034] In this embodiment, the sweet potatoes after primary screening enter the secondary screening frame 51 through the flexible guide channel 9. After the fine screening motor 45 is started, it drives the rotating disk 47 to rotate circumferentially. The eccentric column 48 on the rotating disk 47 moves in a circular motion with the rotating disk, and then drives the connecting seat 50 to move in a reciprocating linear motion through the connecting rod 49. The connecting seat 50 pushes the secondary screening frame 51 to move in a synchronous reciprocating motion. The secondary screening frame 51 slides on the top of the guide seat 56 through the pulleys 55 on both sides to achieve horizontal reciprocating screening. The sweet potatoes move in a reciprocating motion with the screen frame in the secondary screening frame 51. Small impurities smaller than the screen hole 52 fall from the screen hole 52. The finished sweet potatoes move along the screen frame to the guide output port 53 and are gently guided out through the guide surface 54. During the screening process, the cleaning component 57 at the bottom simultaneously unclogs and cleans the screen hole 52.

[0035] Example 9, as Figure 2 and Figure 8 As shown, this embodiment adds the following structure based on embodiment 8: the cleaning component 57 includes several rotating shafts 58 rotatably installed between the two guide seats 56, a cleaning sleeve 59 is installed on the surface of the rotating shaft 58, and a number of evenly arranged cleaning bristles 60 are provided on the surface of the cleaning sleeve 59, and the cleaning bristles 60 are set at the bottom of the secondary screen frame 51.

[0036] In this embodiment, when the secondary screen frame 51 slides back and forth along the guide seat 56, the bottom surface of the screen frame and the cleaning brush bristles 60 move relative to each other. The friction force drives the rotating shaft 58 to rotate. The cleaning brush bristles 60 on the surface of the cleaning sleeve 59 continuously sweep across the screen holes 52 at the bottom of the secondary screen frame 51. The bristles extend into the screen holes 52 to brush off the embedded soil, debris and other impurities, maintaining the permeability of the screen holes 52.

[0037] Example 10, as Figure 2 and Figure 4As shown, this embodiment adds the following structure based on embodiment 1: a fixed seat 61 is installed on the outside of the output end of the flexible guide channel 9, the fixed seat 61 is installed on the top of the secondary screen frame 51, and diversion channels 62 are provided on both sides of the bottom of the impurity guide sleeve 12. The flexible guide channel 9 and the connecting rod 49 are movably arranged between the two diversion channels 62. The bottom output end of the diversion channel 62 is located on the upper side of the impurity collection frame 11. Diversion guide protrusions 63 are provided inside the impurity guide sleeve 12 between the two diversion channels 62.

[0038] In this embodiment, the flexible guide channel 9 is connected to the top of the secondary screen frame 51 via the fixed base 61 and moves synchronously with the secondary screen frame 51. The sweet potato discharged from the material outlet 7 is smoothly guided into the secondary screen frame 51 through the flexible guide channel 9. The primary screening impurities discharged from the impurity outlet 8 enter the impurity guide sleeve 12. Through the diversion and guidance of the diversion guide protrusion 63, the impurities flow to the diversion channels 62 on both sides and finally fall into the impurity collection frame 11 from the bottom output end of the diversion channel 62. The flexible guide channel 9 and the connecting rod 49 pass through the space between the two diversion channels 62 without interfering with each other during the movement process.

[0039] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A secondary screening device for sweet potatoes after harvest, comprising a mounting frame (1), characterized in that: A feeding mechanism (2) is installed on one side of the top of the mounting frame (1). A flexible guide cover (3) is installed at the bottom output end of the feeding mechanism (2). The output end of the flexible guide cover (3) is connected to a primary screening mechanism (4) with an inclined structure. Several elastic suspension components (5) are installed on both sides of the primary screening mechanism (4). The tops of the elastic suspension components (5) are installed on the mounting frame (1). Elastic support components (6) are installed on both sides of the bottom of the primary screening mechanism (4). The elastic support components (6) are installed on both sides of the mounting frame (1). The bottom side of the primary screening mechanism (4) is provided with a material outlet (7) and an impurity outlet (8). The impurity outlet (8) is located in front of the material outlet (7). The output end of the material outlet (7) is connected to a flexible guide channel (9). The output end of the flexible guide channel (9) is provided with a secondary screening mechanism (10). The mounting frame (1) is installed with an impurity collection frame (11) at the bottom of the secondary screening mechanism (10). The output end of the impurity outlet (8) is installed with an impurity guide sleeve (12). The output end of the impurity guide sleeve (12) is located on the upper side of the impurity collection frame (11).

2. The secondary screening device for sweet potatoes after harvest according to claim 1, characterized in that: The feeding mechanism (2) includes a support frame (13), a feeding channel (14) is installed inside the support frame (13), a feeding guide cover (15) is installed on the top of the feeding channel (14), the bottom output end of the feeding channel (14) is connected to the input end of the flexible guide cover (3), a number of evenly arranged rotating shafts (16) are rotatably installed on both sides of the inside of the feeding channel (14), a flow channel (17) is provided between the two sides of the rotating shafts (16), a mounting set (18) is installed on the rotating shaft (16), and a number of evenly arranged strip brushes (19) are installed on the mounting set (18). A drive motor (20) is installed on the outer side of the support frame (13). The power output end of the drive motor (20) is connected to one of the rotating shafts (16). A plurality of transverse transmission components (21) are installed on the side away from the drive motor (20). The plurality of transverse transmission components (21) are installed between two transversely arranged rotating shafts (16). A plurality of vertical transmission components (22) are installed on the side of the drive motor (20) of the material feeding channel (14). The plurality of vertical transmission components (22) are installed between two vertically arranged rotating shafts (16).

3. The secondary screening device for sweet potatoes after harvest according to claim 2, characterized in that: The horizontal transmission assembly (21) and the vertical transmission assembly (22) are the same in size, structure and shape. The horizontal transmission assembly (21) includes two transmission wheels (23) and a transmission belt (24). The two transmission wheels (23) are respectively mounted on the rotating shaft (16), and the transmission belt (24) is arranged between the two transmission wheels (23).

4. The secondary screening device for sweet potatoes after harvest according to claim 3, characterized in that: The primary screening mechanism (4) includes a primary screen frame (25), a vibration motor (26) is installed at the bottom of the primary screen frame (25), a feed inlet (27) is provided on one side of the top of the primary screen frame (25), the output end of the flexible guide cover (3) is installed in the feed inlet (27), the material outlet (7) and the impurity outlet (8) are located at the bottom of the primary screen frame (25), and a number of evenly arranged flexible grid bars (28) are provided in the primary screen frame (25), and a screen gap (29) is provided between two adjacent flexible grid bars (28).

5. A secondary screening device for sweet potatoes after harvest, as described in claim 4, characterized in that: The flexible grid (28) includes a metal core (30), and a flexible wear-resistant layer (31) is provided on the outside of the metal core (30).

6. A secondary screening device for sweet potatoes after harvest, as described in claim 5, characterized in that: The elastic suspension assembly (5) includes a lock seat (32) mounted on a primary screen frame (25), a first spring seat (33) hinged to the outside of the lock seat (32), a first spring (34) mounted on the top of the first spring seat (33), a second spring seat (35) mounted on the free end of the top of the first spring (34), and a suspension seat (36) hinged to the top of the second spring seat (35), which is mounted on the mounting frame (1).

7. A secondary screening device for sweet potatoes after harvest, as described in claim 6, characterized in that: The elastic support assembly (6) includes support plates (37) installed on both sides of the mounting frame (1). The support plates (37) are provided with reinforcing ribs (38) at the connection between the support plates (37) and the mounting frame (1). Several evenly arranged mounting plates (39) are installed on the support plates (37). A second spring (40) is installed on the mounting plate (39). A support seat (41) is installed at the top free end of the second spring (40). The top of the support seat (41) is installed at the bottom of the first-stage screen frame (25). A guide groove (42) is provided on the lower side inside the support seat (41). A third spring (43) is installed in the guide groove (42). A guide column (44) is installed at the bottom free end of the third spring (43). The bottom of the guide column (44) is installed on the mounting plate (39).

8. A secondary screening device for sweet potatoes after harvest, as described in claim 7, characterized in that: The secondary screening mechanism (10) includes a fine screening motor (45). The mounting frame (1) has a motor base (46) at the corresponding fine screening motor (45). The fine screening motor (45) is mounted on the motor base (46). A rotating disk (47) is mounted on the power output end of the fine screening motor (45). An eccentric column (48) is mounted on one side of the rotating disk (47). A connecting rod (49) is hinged to the eccentric column (48). A connecting seat (50) is hinged to the other side of the connecting rod (49). A secondary screen frame (51) is mounted on the other side of the connecting seat (50). The bottom of the frame (51) is provided with a number of evenly arranged screen holes (52). The secondary screen frame (51) is provided with a guide outlet (53) on the side away from the connecting seat (50). The bottom of the output end of the guide outlet (53) is provided with an inclined guide surface (54). A number of evenly arranged pulleys (55) are installed on both sides of the secondary screen frame (51). Guide seats (56) are installed on both sides of the bottom of the mounting frame (1). The pulleys (55) are slidably arranged on the top of the guide seats (56). A number of evenly arranged cleaning components (57) are installed between the two guide seats (56).

9. A secondary screening device for sweet potatoes after harvest, as described in claim 8, characterized in that: The cleaning assembly (57) includes a plurality of rotating shafts (58) rotatably mounted between the guide seats (56) on both sides. A cleaning sleeve (59) is mounted on the surface of the rotating shaft (58). A plurality of evenly arranged cleaning bristles (60) are provided on the surface of the cleaning sleeve (59). The cleaning bristles (60) are located at the bottom of the secondary screen frame (51).

10. A secondary screening device for sweet potatoes after harvest, as described in claim 9, characterized in that: A fixed seat (61) is installed on the outside of the output end of the flexible guide channel (9). The fixed seat (61) is installed on the top of the secondary screen frame (51). The bottom sides of the impurity guide sleeve (12) are provided with diversion channels (62). The flexible guide channel (9) and the connecting rod (49) are movably arranged between the two diversion channels (62). The bottom output end of the diversion channel (62) is located on the upper side of the impurity collection frame (11). The interior of the impurity guide sleeve (12) is provided with diversion guide protrusions (63) between the two diversion channels (62).

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