Automatic cutting, weighing, sorting and packing device for lettuce

Abstract

This invention relates to vegetable processing equipment, specifically an automatic root cutting, weighing, sorting, and packaging device for romaine lettuce. It includes a synchronous belt equidistant drive mechanism mounted on a frame. The synchronous belt equidistant drive mechanism comprises a synchronous belt and tray panels fixed at intervals on the synchronous belt. The tray panels are used for conveying the romaine lettuce. A visual recognition and root cutting mechanism, a weighing mechanism, and a first packaging mechanism are sequentially arranged along the synchronous belt conveying direction. A second packaging mechanism is arranged perpendicular to the synchronous belt conveying direction and adjacent to the weighing mechanism. The visual recognition and root cutting mechanism photographs the romaine lettuce to be cut, obtains the distance between the root of the romaine lettuce and the cutter based on visual recognition technology, and moves the romaine lettuce to be cut below the cutter to complete the automatic root cutting operation. The cut romaine lettuce is weighed and sorted by the weighing mechanism. Those meeting the weight standard are conveyed to the first packaging mechanism for packaging, while those not meeting the weight standard are conveyed to the second packaging mechanism for packaging.

Description

Technical Field

[0001] This invention relates to vegetable processing equipment, specifically to an automatic root cutting, weighing, sorting, and packaging device for romaine lettuce. Background Technology

[0002] As a leafy vegetable, romaine lettuce is widely cultivated throughout my country, both in the north and south, due to its short growth cycle, crisp and tender texture, and high nutritional value. It is one of the most common leafy green vegetables on the market. With the development of agricultural industrialization and the upgrading of the fresh food supply chain, the post-harvest commercial processing of romaine lettuce (such as pre-processing) has become a key link in enhancing the added value of the product.

[0003] Traditional post-harvest cleaning and packaging of romaine lettuce relies heavily on manual labor. The process typically includes: manual removal of the roots (including old roots and any parts that may carry soil), manual visual grading, manual weighing, and manual bundling or bagging. This traditional method suffers from the following technical limitations and pain points: (1) Low precision and efficiency of manual root cutting: It is difficult to ensure the consistency of the cutting position when cutting roots manually with knives. Cutting too shallowly will leave soil and old fibers in the roots, affecting the appearance and taste of the dish; cutting too deep will waste edible leaves and reduce the yield. In addition, the labor intensity of pure manual operation is high, and long-term operation can easily lead to fatigue. The cutting efficiency is difficult to meet the needs of large-scale processing.

[0004] (2) Grading and weighing rely on experience and have large errors: The traditional method of relying on human judgment and feel to estimate weight is difficult to establish a unified standard. This leads to inconsistent product weights after sorting, and it is easy to have short weights or excessive weights, which is not conducive to branded sales and standardized pricing. In high-end supermarket channels, products are easily rejected because they do not meet the specifications.

[0005] (3) Chaotic material flow and zoning management: On the manual assembly line, after the roots are cut and weighed, the lettuce usually needs to be manually transported to different stacking areas for packaging. This decentralized operation mode results in long material flow paths, a messy site, and the lettuce is easily damaged during the handling process (such as crushing and leaf breakage), affecting the freshness and shelf life of the vegetables.

[0006] (4) Difficulty in achieving full traceability: Due to the lack of automated data collection methods, key production data such as root weight, finished product weight, and grading information cannot be recorded and uploaded in real time, making it difficult to accurately calculate production costs and establish an effective quality traceability system.

[0007] Although there are some cleaning and cutting devices on the market for root vegetables (such as carrots and potatoes), romaine lettuce, being a leafy vegetable, cannot be directly applied to existing equipment due to its physical characteristics (loose leaves, easily damaged, and irregular shape). Existing automated equipment generally suffers from problems such as inability to grip flexibly, inaccurate root cutting positioning, and damage to leaves during the conveying process when processing romaine lettuce. Summary of the Invention

[0008] This invention discloses an automatic root cutting, weighing, sorting, and packaging device for romaine lettuce. It can accurately cut the roots, automatically weigh the romaine lettuce, and automatically sort and package it according to the weight, thereby reducing the intensity of manual labor, increasing the yield and processing efficiency, and achieving standardized production.

[0009] To achieve the above objectives, the technical solution adopted by the present invention is as follows: An automatic root cutting, weighing, sorting and packaging device for romaine lettuce includes a synchronous belt equidistant drive mechanism installed on a frame. The synchronous belt equidistant drive mechanism includes a synchronous belt and a tray panel fixed at intervals on the synchronous belt. A visual recognition and root cutting mechanism, a weighing mechanism and a first packaging mechanism are arranged sequentially along the synchronous belt conveying direction. A second packaging mechanism is arranged perpendicular to the synchronous belt conveying direction and adjacent to the weighing mechanism. The visual recognition and root cutting mechanism includes a visual recognition camera, a root cutting gripping cylinder, a root cutting downward moving cylinder, a servo electric cylinder, a root cutting pressing cylinder, and a root cutting cylinder. Pneumatic grippers are installed on the piston rods on both sides of the root cutting gripping cylinder. The piston rod of the root cutting downward moving cylinder is perpendicular to the tray panel and is connected to the root cutting gripping cylinder. The servo electric cylinder drives the root cutting downward moving cylinder to move along the vertical synchronous belt conveying direction. The root cutting pressing cylinder is arranged in parallel with the root cutting cylinder, and the piston rods of both cylinders are perpendicular to the tray panel. The piston rod of the root cutting pressing cylinder is connected to the pressing block, and the piston rod of the root cutting cylinder is connected to the cutter. The weighing mechanism includes a weighing gripping cylinder, a weighing lifting cylinder, a weighing rotating cylinder, a lever drive cylinder, and a transfer support plate. Weighing gripping claws are installed on the piston rods on both sides of the weighing gripping cylinder. The piston rod of the weighing lifting cylinder is perpendicular to the tray panel and is connected to the weighing gripping cylinder. The weighing rotating cylinder is located above the weighing lifting cylinder. The weighing rotating cylinder and the weighing lifting cylinder are connected by a weighing sensor. The lever drive cylinder drives the workstation switching lever to move along a direction perpendicular to the synchronous belt conveying direction. The weighing gripping claws pick up the cut lettuce and obtain the weight of the cut lettuce through the weighing sensor. If the weight is greater than a set threshold, the weighing rotating cylinder drives the cut lettuce to turn so that its root side faces the first packaging mechanism. If the weight is less than the set threshold, the weighing gripping claws place the cut lettuce on the transfer support plate and cause the workstation switching lever to push the cut lettuce to move towards the second packaging mechanism. Both the first and second packaging mechanisms are equipped with a packaging bag adsorption mechanism, a feeding mechanism, and a sealing mechanism.

[0010] Furthermore, a rolling bearing support wheel is mounted on the side of the tray panel facing the timing belt.

[0011] Furthermore, the visual recognition camera is housed inside a light shield, which is open on one side facing the tray panel.

[0012] Furthermore, a slide rail is installed on the frame, with the slide rail located on the side adjacent to the cutter, and a root and stem collection box is installed below the slide rail.

[0013] Furthermore, the weighing mechanism also includes a weighing transfer cylinder, a support arm, a support base, a support rod, and a guide rail. The support base is fixed on the frame, and the weighing transfer cylinder is installed on the top of the support base. The weighing rotary cylinder and the weighing transfer cylinder are arranged back and forth along the vertical synchronous belt conveying direction. The piston rod of the weighing transfer cylinder is arranged along the synchronous belt conveying direction. One end of the support arm is fixed on the weighing rotary cylinder, and the other end is fixedly connected to a moving block that connects to the piston rod of the weighing transfer cylinder. The guide rail is fixed on the top of the support base, and a slider is installed on the guide rail. The slider and the support arm are fixedly connected by the support rod.

[0014] Furthermore, the packaging bag adsorption mechanism includes a packaging bag tray for placing packaging bags, a packaging bag suction plate, a packaging bag lifting cylinder, and a flipping cylinder. The piston rod of the packaging bag lifting cylinder is arranged vertically and is connected to the packaging bag suction plate. The packaging bag suction plate is provided with packaging bag adsorption suction cups. The packaging bag lifting cylinder is connected to the flipping cylinder through a cylinder mounting plate. The flipping cylinder can drive the packaging bag suction plate to flip up and down. The sealing mechanism includes a sealing cylinder located on the upper part of the flipping cylinder. The piston rod of the sealing cylinder is connected to the sealing panel. The sealing panel is provided with a fast-heat sealing strip and a sealing panel suction cup. Opposing baffles are provided opposite to the sealing panel. Sealing buffer strips are provided on the opposing baffles at the positions corresponding to the fast-heat sealing strips. The opposing baffles are also provided with upper suction cups and lower suction cups. A sliding cylinder is provided at the lower part of the flipping cylinder. The flipping cylinder is connected to the sliding table of the sliding cylinder through a connecting plate. Both the sealing cylinder and the sliding cylinder move in the direction of approaching or moving away from the opposing baffles.

[0015] Furthermore, the feeding mechanism of the first packaging mechanism includes a feeding cylinder and a swing cylinder. A swing cylinder mounting bracket is provided between the feeding cylinder and the swing cylinder. One end of the swing cylinder mounting bracket is connected to the swing cylinder, and the other end is connected to the moving block of the feeding cylinder. The output end of the swing cylinder is connected to a swing rod, and one end of the swing rod is connected to a feeding rod.

[0016] Furthermore, the feeding mechanism of the second packaging mechanism includes a conveyor belt, which is adjacent to the transfer support plate.

[0017] Furthermore, a first finished product box is provided at the lower part between the sealing panel and the opposing baffle of the first packaging mechanism, and a second finished product box is provided at the lower part between the sealing panel and the opposing baffle of the second packaging mechanism.

[0018] Furthermore, the automatic root cutting, weighing, sorting, and packaging device for romaine lettuce also includes a vacuum pump, a vacuum tank, a vacuum tank on / off valve, a vacuum sensor, and a one-way valve. The vacuum pump is connected to the vacuum tank through a pipeline equipped with a one-way valve. The vacuum tank is connected to the suction cups of the first packaging mechanism and the second packaging mechanism through a pipeline equipped with a vacuum tank on / off valve. A vacuum sensor is installed on the vacuum tank to monitor the vacuum level.

[0019] This invention employs a synchronous belt equidistant drive mechanism to convey rooted romaine lettuce at equidistant distances across different workstations. Visual recognition technology is used to determine the distance between the root of the romaine lettuce to be cut and the cutting blade, moving the romaine lettuce under the blade to complete the automatic root cutting operation. This improves the standardization of romaine lettuce root cutting and the quality of the finished product, while also reducing the labor intensity of manual root cutting. Furthermore, this invention uses a weighing mechanism to weigh the cut romaine lettuce and sort it according to its weight. Romaine lettuce of different grades is then conveyed to different zones for packaging. Overall, this invention achieves fully automated romaine lettuce root cutting, weighing, sorting, and packaging, improving yield and processing efficiency. Attached Figure Description

[0020] Figure 1 This is a flowchart illustrating the automatic root cutting, weighing, sorting, and packaging device for romaine lettuce in this embodiment. Figure 2 This is a schematic diagram of the automatic root cutting, weighing, sorting, and packaging device for romaine lettuce in the embodiment. Figure 3 for Figure 2 A schematic diagram after the sunshade has been removed; Figure 4 This is a color schematic diagram of the automatic root cutting, weighing, sorting, and packaging device for romaine lettuce in the embodiment. Figure 5 This is a schematic diagram of the synchronous belt equidistant drive mechanism in the embodiment; Figure 6 This is a schematic diagram of the visual recognition and root cutting mechanism in the embodiment; Figure 7 This is a schematic diagram of the weighing mechanism in the embodiment; Figure 8 This is a schematic diagram of the structure of the first packaging mechanism in the embodiment; Figure 9 This is a structural schematic diagram of the first packaging mechanism from another perspective in the embodiment; Figure 10 This is a schematic diagram of the structure of the second packaging mechanism in the embodiment; Figure 11 This is a structural schematic diagram of the second packaging mechanism from another perspective in the embodiment.

[0021] Figure label: 1. Rack; 2. Synchronous belt equidistant drive mechanism; 201. Servo motor; 202. Synchronous belt; 203. Pallet panel; 204. Synchronous belt connecting block; 205. Rolling bearing support wheel; 206. Working position support plate; 207. Driving synchronous belt pulley; 208. Driven synchronous belt pulley; 3. Visual recognition and root cutting mechanism; 301. Light shield; 302. Visual recognition camera; 303. Pneumatic gripper; 304. Servo electric cylinder; 305. Root cutting gripping cylinder; 306. Root cutting downward movement cylinder; 307. Root cutting clamping cylinder; 308. Pressure block; 309. Root cutting cylinder; 310. Cutting blade; 311. Slide rail; 4. Weighing mechanism; 401. Weighing gripper; 402. Weighing gripping cylinder; 403. Workstation switching lever; 404. Weighing lifting cylinder; 405. Weighing sensor; 406. Weighing rotary cylinder; 407. Guide rail; 408. Support rod; 409. Support arm; 410. Weighing transfer cylinder; 411. Support base; 412. Lever drive cylinder; 413. Transfer support plate; 5. First Packaging Mechanism; 501. Packaging Strap Pallet; 502. Packaging Strap Suction Plate; 503. Packaging Strap Lifting Cylinder; 504. Cylinder Mounting Plate; 505. Tilting Cylinder; 506. Sealing Cylinder; 507. Feeding Cylinder; 508. Feeding Cylinder Mounting Bracket; 509. Swinging Cylinder Mounting Bracket; 510. Swinging Cylinder; 511. Swing Rod; 512. Feeding Rod; 513. Packaging Strap Adsorption Suction Cup; 514. Slide Table Cylinder; 515. Sealing Cylinder Mounting Base; 516. Sealing Panel; 517. Quick-Heating Sealing Strip; 518. Sealing Panel Suction Cup; 519. Opposing Baffle; 520. Sealing Buffer Strip; 521. Upper Suction Cup of Baffle; 522. Lower Suction Cup of Baffle; 6. Second packaging mechanism; 601. Conveyor belt; 7. Vacuum generating system; 701. Vacuum pump; 702. Vacuum tank; 8. Romaine lettuce; 801. Romaine lettuce to be cut into roots; 802. Romaine lettuce with roots already cut; 803. Romaine lettuce to be arranged; 804. Romaine lettuce after packaging; 9. Collection box; 901. Root and stem collection box; 902. First finished product box; 903. Second finished product box. Detailed Implementation

[0022] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

[0023] To address the technical challenges of low precision and efficiency in manual root cutting, reliance on experience for grading and weighing, and high labor intensity in traditional post-harvest cleaning and packaging of romaine lettuce, this embodiment discloses a fast, convenient, and low-cost automated root cutting, weighing, sorting, and packaging device for romaine lettuce. Its structure is as follows: Figures 2 to 4 As shown, the system mainly includes a frame 1, a synchronous belt equidistant drive mechanism 2, a vision recognition and root-cutting mechanism 3, a weighing mechanism 4, a first packaging mechanism 5, a second packaging mechanism 6, a vacuum generating system 7, and a collection box 9. The synchronous belt equidistant drive mechanism 2 is mainly used to transport lettuce 801 between different workstations; the vision recognition and root-cutting mechanism 3 mainly identifies the root position of the lettuce 801 to be cut and determines the distance between the root and the cutter, moving the lettuce 801 to be cut under the cutter to complete the automatic root-cutting operation; the weighing mechanism 4 mainly obtains the weight of the cut lettuce 802 by grabbing and lifting it, and determines which packaging mechanism to send the cut lettuce 802 to for packaging based on the weight; the first packaging mechanism 5 is used to package the cut lettuce 802 that meets the weight standard; the second packaging mechanism 6 is used to package the cut lettuce 802 that does not meet the weight standard.

[0024] In this embodiment, the structure of the synchronous belt equidistant drive mechanism 2 is as follows: Figure 5 As shown, a servo motor 201 drives two parallel synchronous belts 202 for equidistant step conveying. Two active synchronous pulleys 207 connected by shafts are mounted on the frame 1, and two driven synchronous pulleys 208 connected by shafts are mounted at the other end of the frame 1. The two synchronous belts 202 are wound around the opposing active and driven synchronous pulleys 207 and 208, respectively. The servo motor 201 drives the active synchronous pulleys 207 to rotate, and the synchronous belts 202 drive the driven synchronous pulleys 208 to rotate synchronously. Nine pallet panels 203 are evenly spaced between the two synchronous belts 202, and each pallet panel 203 is fixed to the synchronous belt 202 by a synchronous belt connecting block 204. A rolling bearing support wheel 205 is mounted on the side of each pallet panel 203 facing the synchronous belt 202. Figure 5 The three pallet panels 203 located on the top surface are in the working position. A working position support plate 206 is horizontally set at the working position. When each pallet panel 203 rotates to the working position, the rolling bearing support wheel 205 rolls along the working position support plate 206 to provide support force. Figure 5 The synchronous belt 202 rotates counterclockwise (from) Figure 4 (Note that the timing belt 202 rotates clockwise). From right to left, the tray panels are for the first, second, and third workstations. The first workstation is for loading. The operator needs to remove the yellow leaves from the lettuce 8 beforehand, and then place the lettuce (with roots and removed yellow leaves) on the tray panel for the first workstation. Figure 4As shown, the roots of the lettuce 801 to be cut on the tray panel of the first workstation must face the same direction, which in this embodiment all face the side of the second packaging mechanism 6. The second workstation is the visual recognition and root cutting workstation, and the third workstation is the weighing and sorting workstation.

[0025] by Figure 4 For reference, the conveying direction of the synchronous belt 202 is from left to right. The visual recognition and root cutting mechanism 3, the weighing mechanism 4 and the first packaging mechanism 5 are arranged sequentially along the conveying direction of the synchronous belt 202, while the second packaging mechanism 6 is arranged perpendicular to the conveying direction of the synchronous belt 202 and adjacent to the weighing mechanism 4.

[0026] The structure of the visual recognition and root-cutting mechanism 3 in this embodiment is as follows: Figure 6 As shown, the system includes a visual recognition camera 302, a root-cutting gripping cylinder 305, a root-cutting downward moving cylinder 306, a servo electric cylinder 304, a root-cutting pressing cylinder 307, and a root-cutting cylinder 309. The visual recognition and root-cutting mechanism 3 is entirely housed within a light shield 301, which is open only to the side facing the tray panel 203 to prevent changes in natural light from affecting the recognition stability of the visual recognition camera 302. A servo electric cylinder 304 is mounted on the frame 1 at the location of the light shield 301. The piston moving block of the servo electric cylinder 304 moves along the vertical conveying direction of the synchronous belt 202. A connecting plate is fixedly mounted on the piston moving block of the servo electric cylinder 304, and a root-cutting downward moving cylinder 306 is fixedly mounted at the bottom of the connecting plate. The piston rod of the root-cutting downward moving cylinder 306 faces the direction of the piston, and the root-cutting gripping cylinder 305 is fixed to the piston rod of the root-cutting downward moving cylinder 306. The piston rod of the root-cutting gripping cylinder 305 is parallel to the direction of movement of the synchronous belt 202. Pneumatic grippers 303 are installed on the piston rods on both sides of the root-cutting gripping cylinder 305. A vision recognition camera 302 is fixedly installed on the frame 1 opposite to the mounting position of the servo electric cylinder 304. Root-cutting pressing cylinder 307 and root-cutting cylinder 309 are installed side-by-side on the frame 1 near the second packaging mechanism 6. The piston rods of both root-cutting pressing cylinder 307 and root-cutting cylinder 309 point downwards and are perpendicular to the tray panel 203. A pressure block 308 is fixedly connected to the piston rod of root-cutting pressing cylinder 307, and a cutter 310 is fixedly connected to the piston rod of root-cutting cylinder 309. Root-cutting cylinder 309 is closer to the second packaging mechanism 6 than root-cutting pressing cylinder 307. Figure 4 As shown, a slide rail 311 is fixedly installed on the frame 1 on the side near the second packaging mechanism 6, directly opposite the tray panel of the second workstation. A root and stem collection box 901 is set below the slide rail 311. After the rooted lettuce 801 is transported from the first workstation to the second workstation, the root identification and root cutting operation are completed, and the cut roots fall into the root and stem collection box 901 along the slide rail 311.

[0027] The structure of the weighing mechanism 4 in this embodiment is as follows: Figure 7As shown, a support base 411 is fixedly installed on the frame 1 parallel to the conveying direction of the synchronous belt 202. A guide rail 407 and a weighing transfer cylinder 410 are fixedly installed on the top of the support base 411. The length direction of the guide rail 407 and the moving direction of the piston moving block of the weighing transfer cylinder 410 are both parallel to the conveying direction of the synchronous belt 202. A weighing rotary cylinder 406 is set at the opposite end of the weighing transfer cylinder 410. The weighing rotary cylinder 406 and the piston moving block of the weighing transfer cylinder 410 are fixedly connected by a support arm 409. A slider is installed on the guide rail 407, and a support rod 408 is fixedly installed on the slider. The top of the support rod 408 is fixedly connected to the support arm 409. A weighing lifting cylinder 404 is installed at the lower part of the weighing rotary cylinder 406. The weighing rotary cylinder 406 and the weighing lifting cylinder 404 are fixedly connected by a weighing sensor 405. The piston rod of the weighing lifting cylinder 404 faces downward, and a weighing gripping cylinder 402 is fixedly installed on the piston rod. The piston rod of the weighing gripping cylinder 402 is parallel to the conveying direction of the synchronous belt 202. Weighing gripping claws 401 are installed on the piston rods on both sides of the weighing gripping cylinder 402. A lever drive cylinder 412 is fixedly installed on the frame 1 perpendicular to the moving direction of the synchronous belt 202. The vertical section of the L-shaped workstation switching lever 403 is fixed on the piston moving block of the lever drive cylinder 412. The lever drive cylinder 412 drives the workstation switching lever 403 to move along the conveying direction perpendicular to the synchronous belt 202. A transfer support plate 413 is provided on the side facing the third workstation pallet panel and close to the second packaging mechanism 6.

[0028] The first packaging mechanism 5 and the second packaging mechanism 6 in this embodiment have basically the same structure. Both are equipped with a packaging bag adsorption mechanism, a feeding mechanism and a packaging bag sealing mechanism. The first packaging mechanism 5 will be used as an example for detailed description below.

[0029] The structure of the first packaging mechanism 5 in this embodiment is as follows: Figure 8 and Figure 9As shown, the bag suction mechanism includes a bag tray 501 for placing bags, a bag suction plate 502 for suctioning bags, a bag lifting cylinder 503, and a flipping cylinder 505. The bag tray 501 is horizontally arranged. The piston rod of the bag lifting cylinder 503 faces downward and is fixedly connected to the bag suction plate 502. The bag suction plate 502 is equipped with bag suction cups 513. The bag lifting cylinder 503 is connected to the flipping cylinder 505 through a cylinder mounting plate 504. The flipping cylinder 505 can drive the bag suction plate 502 to flip up and down. The bag sealing mechanism includes a sealing cylinder 506 located above the flipping cylinder 505. The piston rod of the sealing cylinder 506 is fixedly connected to a sealing panel 516. The sealing panel 516 is equipped with a quick-heat sealing strip 517 and a sealing panel suction cup 518. An L-shaped opposing baffle 519 is provided on the side opposite to the sealing panel 516. A sealing buffer strip 520 is provided on the vertical plate of the opposing baffle 519 corresponding to the quick-heat sealing strip 517. An upper suction cup 521 and a lower suction cup 522 are respectively provided on the vertical plate of the opposing baffle 519 below the sealing buffer strip 520. The sealing cylinder 506 drives the sealing panel 516 to move closer to or away from the opposing baffle 519. A sliding cylinder 514 is provided below the tilting cylinder 505. The tilting cylinder 505 is connected to the sliding table of the sliding cylinder 514 via a connecting plate. The sliding cylinder 514 drives the tilting cylinder 505 to move closer to or away from the opposing baffle 519. The feeding mechanism includes a feeding cylinder 507 and a swing cylinder 510. A feeding cylinder mounting bracket 508 is fixed to the frame 1. The feeding cylinder 507 is mounted on the feeding cylinder mounting bracket 508. The piston moving block of the feeding cylinder 507 moves along the conveying direction of the parallel synchronous belt 202. The piston moving block of the feeding cylinder 507 is fixedly connected to the swing cylinder 510 via a swing cylinder mounting bracket 509. The output end of the swing cylinder 510 is connected to a swing rod 511. The free end of the swing rod 511 is connected to a material-pushing rod 512, which is perpendicular to the swing rod 511. A first finished product box 902 is provided below the sealing panel 516 and the opposing baffle 519.

[0030] The bag suction mechanism and bag sealing mechanism in the second packaging mechanism 6 of this embodiment are structurally identical to those described in the first packaging mechanism 5, and will not be repeated here. The second packaging mechanism 6 differs from the first packaging mechanism 6 in its positional arrangement relative to the weighing mechanism 4; therefore, the main difference lies in the feeding mechanism. The second packaging mechanism 6 does not have the feeding mechanism found in the first packaging mechanism 5. Figure 10 and Figure 11As shown, the feeding mechanism in the second packaging mechanism 6 adopts a conveyor belt 601. The conveyor belt 601 is adjacent to the transfer support plate 413. After the cut lettuce 802 falls from the conveyor belt 601, it is located between the opposing baffle and the sealing panel of the second packaging mechanism 6. The second finished product box 903 is set below the opposing baffle and the sealing panel of the second packaging mechanism 6.

[0031] In this embodiment, the vacuum generating system 7 mainly provides vacuum suction for the suction cups on the first packaging mechanism 5 and the second packaging mechanism 6, such as... Figure 4 As shown, the vacuum generating system 7 mainly includes a vacuum pump 701, a vacuum tank 702, a vacuum tank on / off valve, a vacuum sensor, and a high-precision check valve. The vacuum pump 701 is connected to the vacuum tank 702 via a pipeline equipped with a high-precision check valve. The vacuum tank 702 is connected to the vacuum suction cups of the first packaging mechanism 5 and the second packaging mechanism 6 via a pipeline equipped with a vacuum tank on / off valve. A vacuum sensor is installed on the vacuum tank 702 to monitor the vacuum level. The vacuum tank on / off valve controls the suction of the multiple vacuum suction cups. Air in the vacuum tank 702 is extracted by the vacuum pump 701 to achieve the required vacuum level. The vacuum tank 702 can slow down the rate of vacuum decrease when the vacuum suction cups are working, thus achieving a longer vacuum suction capacity. The vacuum sensor monitors the vacuum level of the vacuum tank 702 in real time. A vacuum level threshold (e.g., 95%) is set in the PLC lower-level control system, thereby enabling the vacuum pump 701 to operate intermittently, reducing its power consumption and heat generation, and thus avoiding the risk of damage from prolonged operation.

[0032] A high-precision check valve connects vacuum pump 701 and vacuum tank 702. Inside the high-precision check valve is an open-ended damping spring. The spring's compression direction pipe is connected to vacuum pump 701, and the spring's extension direction pipe is connected to vacuum tank 702. The spring is normally in a compressed state. Assume the air pressure in vacuum tank 702 is... P 1 The air pressure in vacuum pump 701 is P 2 The cross-sectional area of ​​the valve core on the side near vacuum tank 702 is... S 1 The cross-sectional area of ​​the valve core on the side closest to vacuum pump 701 is... S 2 The compressive force of the spring is F The force relationship of the valve core is as follows: P 1 ·S 1 =P 2 ·S 2 +FFrom the above force equations, it can be seen that under normal pressure... P 1 =P 2 , S 1 and S 2 Very close, the spring's compression force is sufficient to fix the valve core in the disconnected position, that is, the high-precision check valve is in the closed state; when the vacuum pump 701 starts working, the pressure in the pipe near the vacuum pump 701 of the check valve... P 2 If the pressure drops sharply, the air pressure on the side of the high-precision one-way valve core near the vacuum tank 702 will be greater than that on the side near the vacuum pump 701. At this time, the spring will be compressed to open the valve core, and the air in the vacuum tank 702 will be drawn out to the side near the vacuum pump 701 and discharged into the atmosphere. The force relationship of the valve core is as follows: P 1 ·S 1 >P 2 ·S 2 +F As air is extracted from vacuum tank 702, the vacuum level within vacuum tank 702 gradually increases, and the air pressure within vacuum tank 702... P 1 Gradually decrease the vacuum level. Assuming the vacuum level on the side of vacuum pump 701 is close to 100%, then... P 2 If we consider it to be close to zero, then the valve core opening condition becomes... P 1 ·S 1 and F A balance relationship exists, as long as it exists. P 1 ·S 1 >F Then the valve core can open, and the air in the vacuum tank 702 can be extracted, further increasing the vacuum level; as the vacuum level in the vacuum tank 702 reaches a certain value, the force condition of the valve core reaches... P 1 ·S 1 =F In a balanced state, the vacuum level in vacuum tank 702 no longer increases. When the vacuum level in vacuum tank 702 reaches a set threshold, vacuum pump 701 stops working; when the vacuum suction cup is opened... P 1The vacuum level rises instantly, and when it reaches the set vacuum threshold, the vacuum pump 701 is activated. This cycle continues to maintain a stable vacuum level in the vacuum tank 702. From the force relationship of the valve core, it can be seen that the vacuum level achievable by the vacuum tank 702 is related to the opening force of the high-precision one-way valve's compression spring. F Therefore, a one-way valve with a smaller opening force should be selected to improve the vacuum level that the vacuum tank 702 can ultimately achieve, thereby improving the working capacity of the entire vacuum system.

[0033] The device designed in this embodiment, combined with Figure 1 As shown, the working process of this device is explained below: Step 1): Loading; that is: manually placing the romaine lettuce 801 to be cut on the first workstation tray panel 203, with the roots facing the second packaging mechanism 6.

[0034] Step 2): Root identification and root cutting; The synchronous belt 202 rotates to transport the romaine lettuce 801 to be cut from the tray panel 203 of the first workstation to the second workstation. The visual recognition camera 302 takes a picture, and the system obtains the image information of the root-stem connection of the romaine lettuce. Based on the existing image segmentation and edge extraction algorithm (this invention does not involve the improvement of the method), the obtained image information of the root-stem connection is compared with the sample image information saved in the previous teaching to obtain the pose coordinate adjustment data of the romaine lettuce 801 to be cut (i.e., the distance between the root and the cutter). Then, the root-cutting gripping cylinder 305 drives the pneumatic gripper 303 to grab the romaine lettuce 801 to be cut. The root-cutting lowering cylinder 306 drives it to be lifted upward to a certain height, and then the servo electric cylinder 304 drives it to move towards the cutter 310, placing the romaine lettuce 801 to be cut under the cutter 310 with the root facing the cutter 310. Next, the root-cutting and pressing cylinder 307 drives the pressing block 308 to move downwards. The pressing block 308 presses down on the part above the root to fix it. Finally, the root-cutting cylinder 309 drives the cutter 310 to cut downwards to remove the root. The removed rootstock falls into the rootstock collection box 901 along the slide 311.

[0035] Step 3): Weighing and sorting; The chopped lettuce 802 moves from the second station to the third station via the synchronous belt 202. The weighing gripping cylinder 402 drives the weighing gripping claw 401 to grasp the chopped lettuce 802. Subsequently, the weighing lifting cylinder 404 lifts the chopped lettuce 802 to a certain height, and the weight of the chopped lettuce 802 is obtained through the weighing sensor 405. In this embodiment, the lettuce is divided into two grades based on weight. The system presets a weight threshold. If the current weight of the lettuce is greater than the preset weight threshold, it is classified as a superior grade; otherwise, it is classified as a inferior grade. The superior grade is packaged by the first packaging mechanism 5, and the inferior grade is packaged by the second packaging mechanism 6.

[0036] Since the first packaging mechanism 5 is in the conveying direction of the synchronous belt 202 and is located below the weighing mechanism 4, as Figure 7 As shown, the roots of the chopped lettuce 802 placed on the tray panel of the third work station were originally facing the second packaging mechanism 6. For the high-grade chopped lettuce 802, in order to facilitate the packaging operation of the first packaging mechanism 5, the chopped lettuce 802 needs to be rotated 90° by the weighing mechanism 4 so that the roots face the first packaging mechanism 5. That is, after weighing is completed, the weighing transfer cylinder 410 drives the weighing rotation cylinder 406, the weighing lifting cylinder 404, the weighing gripping cylinder 402, and the chopped lettuce 802 as a whole to move about 80mm closer to the first packaging mechanism 5. Then, the weighing rotation cylinder 406 drives the weighing lifting cylinder 404, the weighing gripping cylinder 402, and the chopped lettuce 802 below to rotate counterclockwise by 90° until the roots face the first packaging mechanism 5. Finally, the weighing gripping claw 401 releases and places the rotated lettuce back onto the third workstation tray panel 203. For the lower grade chopped lettuce 802, after weighing, the weighing gripper 401 directly places the chopped lettuce 802 on the third station tray panel 203 in its original direction. Then, the lever-driven cylinder 412 drives the station switching lever 403 to push the chopped lettuce 802 from the third station tray panel 203 through the transfer support plate 413 to the conveyor belt 601, and then the second packaging mechanism 6 performs the packaging operation.

[0037] Step 4): Packaging work; Taking the first packaging mechanism 5 as an example, such as Figure 8 and Figure 9 As shown, Figure 8The third workstation tray panel shows 803 lettuce to be rotated. Before packaging, the lettuce 803 needs to be rotated 90° by the weighing mechanism 4. Then, the swing cylinder 510 drives the swing rod 511 to flip downwards (before packaging, the swing rod 511 is flipped back to its original position to avoid interference). Then, the feeding cylinder 507 drives the swing rod 511 to push the rotated lettuce to the top of the opposite baffle 519. Packaging bags are stacked on the packaging bag tray 501. The packaging bag lifting cylinder 503 drives the packaging bag suction plate 502 to move downwards and press it on the packaging bag tray 501. Vacuum adsorption is activated, allowing the packaging bag suction cup 513 to adsorb the top packaging bag. The packaging bag lifting cylinder 503 rises to lift the packaging bag upwards, and then the flipping cylinder 505 drives it to flip counterclockwise by 90°. At this point, the side of the packaging bag that is being suctioned is positioned precisely on the wall of the sealing panel 516 facing the opposing baffle 519. Vacuum suction is activated, causing the suction cups 518 of the sealing panel to adhere to the sealing area of ​​the packaging bag. Next, the sealing cylinder 506 and the sliding cylinder 514 move synchronously towards the opposing baffle 519, bringing the non-suctioned side of the packaging bag against the vertical plate of the opposing baffle 519. The upper suction cup 521 and the lower suction cup 522 of the baffle are activated, adsorbing the other side of the packaging bag onto the opposing baffle 519. Then, the sealing cylinder 506 and the sliding cylinder 514 retract synchronously, causing the packaging bag to open. Finally, the rotating lettuce is pushed into the packaging bag by the feeding rod 512. After the romaine lettuce is bagged, the suction cup 513 releases the bag, and the sealing cylinder 506 moves toward the opposing baffle 519, causing the bag to be clamped by the sealing panel 516 and the opposing baffle 519. The quick-heat sealing strip 517 is activated to heat up, and the bag is sealed by heat under the compression of the quick-heat sealing strip 517 and the sealing buffer strip 520. Finally, the vacuum suction force of all suction cups is broken, allowing the packaged romaine lettuce 804 to fall into the first finished product box 902.

[0038] The second packaging mechanism 6 is the same as the first packaging mechanism 5 described above. However, when feeding, the chopped lettuce 802 is conveyed by the conveyor belt 601 and falls into the already opened packaging bag. After the packaging bag is sealed, it falls into the second finished product box 903. The rest is the same as the above description of the first packaging mechanism 5.

[0039] The device in this embodiment can record and save the root-cutting location and weight value of each lettuce in a host computer database, achieving standardized root-cutting operations and improving the quality of the finished product. The device designed in this invention has the following characteristics: ① Manually cutting the roots of lettuce with knives makes it difficult to ensure the consistency of the cutting position. This embodiment uses a high-definition vision camera to identify the position coordinates of the root-stem connection point of the lettuce, improving the standardization of the root-cutting operation and the quality of the finished product, while also reducing the labor intensity of manual root cutting; ② This embodiment uses a weighing mechanism 4 to weigh and sort the root-cut lettuce online, improving the weight consistency of the packaged finished product, avoiding situations where the weight does not meet the standards at the sales location, which could affect customer evaluations, and also providing data traceability for the sold products. A quick technical solution is provided; ③ This embodiment uses a vacuum pump 701, a high-precision one-way valve, and a vacuum tank 702 to achieve a dynamic balance vacuum generation system with a high vacuum threshold. The system's vacuum level can be stabilized at over 95%, and the vacuum pump 701 does not need to work continuously, reducing energy consumption and the probability of damage, thereby improving the stability of the entire equipment; ④ This embodiment uses a vacuum adsorption system to achieve rapid feeding and opening of the packaging bags, and a fast-heat sealing strip 517 to achieve rapid sealing of the lettuce after it is put into the bag. After sealing, the finished bag automatically falls into the finished product box, realizing the rapid bagging and sealing of lettuce.

[0040] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. An automatic root cutting, weighing, sorting, and packaging device for romaine lettuce, characterized in that: The system includes a synchronous belt equidistant drive mechanism mounted on a frame. The synchronous belt equidistant drive mechanism includes a synchronous belt and a tray panel fixed at intervals on the synchronous belt. A visual recognition and root cutting mechanism, a weighing mechanism and a first packaging mechanism are sequentially arranged along the synchronous belt conveying direction. A second packaging mechanism is arranged perpendicular to the synchronous belt conveying direction and adjacent to the weighing mechanism. The visual recognition and root cutting mechanism includes a visual recognition camera, a root cutting gripping cylinder, a root cutting downward moving cylinder, a servo electric cylinder, a root cutting pressing cylinder, and a root cutting cylinder. Pneumatic grippers are installed on the piston rods on both sides of the root cutting gripping cylinder. The piston rod of the root cutting downward moving cylinder is perpendicular to the tray panel and is connected to the root cutting gripping cylinder. The servo electric cylinder drives the root cutting downward moving cylinder to move along the vertical synchronous belt conveying direction. The root cutting pressing cylinder is arranged in parallel with the root cutting cylinder, and the piston rods of both cylinders are perpendicular to the tray panel. The piston rod of the root cutting pressing cylinder is connected to the pressing block, and the piston rod of the root cutting cylinder is connected to the cutter. The weighing mechanism includes a weighing gripping cylinder, a weighing lifting cylinder, a weighing rotating cylinder, a lever drive cylinder, and a transfer support plate. Weighing gripping claws are installed on the piston rods on both sides of the weighing gripping cylinder. The piston rod of the weighing lifting cylinder is perpendicular to the tray panel and is connected to the weighing gripping cylinder. The weighing rotating cylinder is located above the weighing lifting cylinder. The weighing rotating cylinder and the weighing lifting cylinder are connected by a weighing sensor. The lever drive cylinder drives the workstation switching lever to move along a direction perpendicular to the synchronous belt conveying direction. The weighing gripping claws pick up the cut lettuce and obtain the weight of the cut lettuce through the weighing sensor. If the weight is greater than a set threshold, the weighing rotating cylinder drives the cut lettuce to turn so that its root side faces the first packaging mechanism. If the weight is less than the set threshold, the weighing gripping claws place the cut lettuce on the transfer support plate and cause the workstation switching lever to push the cut lettuce to move towards the second packaging mechanism. Both the first and second packaging mechanisms are equipped with a packaging bag adsorption mechanism, a feeding mechanism, and a sealing mechanism.

2. The automatic root cutting, weighing, sorting, and packaging device for romaine lettuce according to claim 1, characterized in that: Rolling bearing support wheels are mounted on the side of the tray panel facing the timing belt.

3. The automatic root cutting, weighing, sorting, and packaging device for romaine lettuce according to claim 1, characterized in that: The visual recognition camera is housed inside a light shield, which is open on one side facing the tray panel.

4. The automatic root cutting, weighing, sorting, and packaging device for romaine lettuce according to claim 1, characterized in that: The frame is equipped with a slide rail, which is installed on the side near the cutter, and a root and stem collection box is set below the slide rail.

5. The automatic root cutting, weighing, sorting, and packaging device for romaine lettuce according to claim 1, characterized in that: The weighing mechanism also includes a weighing transfer cylinder, a support arm, a support base, a support rod, and a guide rail. The support base is fixed on the frame, and the weighing transfer cylinder is installed on the top of the support base. The weighing rotary cylinder and the weighing transfer cylinder are arranged back and forth along the vertical synchronous belt conveying direction. The piston rod of the weighing transfer cylinder is arranged along the synchronous belt conveying direction. One end of the support arm is fixed on the weighing rotary cylinder, and the other end is fixedly connected to a moving block that connects to the piston rod of the weighing transfer cylinder. The guide rail is fixed on the top of the support base, and a slider is installed on the guide rail. The slider and the support arm are fixedly connected by the support rod.

6. The automatic root cutting, weighing, sorting, and packaging device for romaine lettuce according to claim 1, characterized in that: The packaging bag adsorption mechanism includes a packaging bag tray for placing packaging bags, a packaging bag suction plate, a packaging bag lifting cylinder, and a flipping cylinder. The piston rod of the packaging bag lifting cylinder is arranged vertically and is connected to the packaging bag suction plate. The packaging bag suction plate is equipped with packaging bag adsorption suction cups. The packaging bag lifting cylinder is connected to the flipping cylinder through a cylinder mounting plate. The flipping cylinder can drive the packaging bag suction plate to flip up and down. The sealing mechanism includes a sealing cylinder located on the upper part of the flipping cylinder. The piston rod of the sealing cylinder is connected to the sealing panel. The sealing panel is provided with a fast-heat sealing strip and a sealing panel suction cup. Opposing baffles are provided opposite to the sealing panel. Sealing buffer strips are provided on the opposing baffles at the positions corresponding to the fast-heat sealing strips. The opposing baffles are also provided with upper suction cups and lower suction cups. A sliding cylinder is provided at the lower part of the flipping cylinder. The flipping cylinder is connected to the sliding table of the sliding cylinder through a connecting plate. Both the sealing cylinder and the sliding cylinder move in the direction of approaching or moving away from the opposing baffles.

7. The automatic root cutting, weighing, sorting, and packaging device for romaine lettuce according to claim 1, characterized in that: The feeding mechanism of the first packaging mechanism includes a feeding cylinder and a swing cylinder. A swing cylinder mounting bracket is provided between the feeding cylinder and the swing cylinder. One end of the swing cylinder mounting bracket is connected to the swing cylinder, and the other end is connected to the moving block of the feeding cylinder. The output end of the swing cylinder is connected to a swing rod, and one end of the swing rod is connected to a feeding rod.

8. The automatic root cutting, weighing, sorting, and packaging device for romaine lettuce according to claim 1, characterized in that: The feeding mechanism of the second packaging mechanism includes a conveyor belt, which is adjacent to the transfer support plate.

9. The automatic root cutting, weighing, sorting, and packaging device for romaine lettuce according to claim 6, characterized in that: A first finished product box is provided at the lower part between the sealing panel and the opposing baffle of the first packaging mechanism, and a second finished product box is provided at the lower part between the sealing panel and the opposing baffle of the second packaging mechanism.

10. The automatic root cutting, weighing, sorting, and packaging device for romaine lettuce according to claim 6, characterized in that: The automatic root cutting, weighing, sorting, and packaging device for romaine lettuce also includes a vacuum pump, a vacuum tank, a vacuum tank on / off valve, a vacuum sensor, and a one-way valve. The vacuum pump is connected to the vacuum tank through a pipeline equipped with a one-way valve. The vacuum tank is connected to the suction cups of the first packaging mechanism and the second packaging mechanism through a pipeline equipped with a vacuum tank on / off valve. A vacuum sensor is installed on the vacuum tank to monitor the vacuum level.

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