Backpack type coffee fruit selective picking and grading integrated machine

Abstract

The application discloses a kind of back air suction type coffee fruit selective picking and grading integrated machine, belong to agricultural harvesting machinery technical field.To solve the problems that existing coffee picking relies on manual, low efficiency and mechanical picking cannot distinguish fruit maturity and need additional grading, the application adopts air suction type picking method, including picking head, pipeline, collection box, fan, harness, handle and switch.Picking head is installed at the inlet end of pipeline, handle is installed at the upper end of pipeline, the outlet end of pipeline is connected with the inside of collection box, fan is installed on the side of collection box, switch is installed at the lower end of fan, and harness is provided on the outer wall of collection box.The application uses air suction type as the basic picking method, realizes the integration of maturity selective picking and post-harvest instant grading under the premise of not damaging branches, significantly improves the picking efficiency and fresh fruit quality.

Description

Technical Field

[0001] This invention belongs to the field of agricultural harvesting machinery technology, specifically a backpack-type air-suction coffee cherry selective harvesting and grading integrated machine. Background Technology

[0002] As an important economic crop, coffee harvesting is one of the most labor-intensive processes in coffee production. Currently, coffee cherries are mainly harvested manually, with workers picking ripe (red) cherries one by one, leaving unripe green cherries on the tree for later harvests. This method suffers from high labor intensity, low efficiency, and high labor costs.

[0003] Existing mechanized coffee cherry harvesting equipment, particularly large vibratory or pneumatic harvesters, is generally bulky and heavy, making them unsuitable for coffee plantations in hilly and mountainous areas like Yunnan. These regions have scattered planting plots, undulating terrain, and narrow row spacing, preventing large equipment from entering or maneuvering flexibly. Therefore, there is an urgent need for a compact, lightweight, and single-handed backpack-type coffee cherry harvesting device to meet the practical needs of flexible operations in hilly and mountainous terrain.

[0004] Existing mechanized coffee harvesting equipment mainly includes two types: vibratory harvesters and pneumatic harvesters. Vibratory harvesters use high-frequency vibration to detach the cherries, but this can easily damage the branches and cannot differentiate between ripe cherries, leading to the harvesting of unripe cherries and affecting the final coffee quality. While some pneumatic harvesters can improve harvesting efficiency, their fixed negative pressure suction cannot selectively harvest based on the ripeness of the cherries. Post-harvest grading still requires manual labor or additional equipment, and the accumulation of harvested cherries makes them prone to mold growth, resulting in losses.

[0005] Therefore, there is an urgent need in this field for a coffee fruit harvesting device that can simultaneously achieve selective harvesting based on ripeness, immediate post-harvest grading, and is compact and easy to operate. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention provides a backpack-type air-suction coffee cherry selective harvesting and grading integrated machine, which solves the problems of low efficiency and high labor intensity of manual harvesting; large machinery being unable to adapt to hilly and mountainous terrain; the high center of gravity of backpack-type air-suction equipment and the limitation of posture due to hose restraint; and existing air-suction harvesting machines being unable to distinguish the ripeness of the fruit and requiring additional grading after harvesting.

[0007] To achieve the above objectives, the present invention provides the following technical solution: a backpack-type air-suction coffee cherry selective harvesting and grading integrated machine, comprising a harvesting head 1, a pipe 2, a collection box 3, a fan 4, a shoulder strap 5, a handle 6, and a switch 7; wherein, the discharge port of the harvesting head 1 is connected to the inlet end of the pipe 2, the handle 6 is installed above the pipe 2, the outlet end of the pipe 2 is connected to the inlet of the collection box 3, the fan 4 is installed on the outer side of the side wall opposite to the inlet of the collection box 3, the switch 7 connected to the fan 4 is installed at the lower end of the fan 4, the air intake of the fan 4 is connected to the airflow channel inside the collection box 3, and the shoulder strap 5 is connected to the front end of the collection box 3.

[0008] Specifically, the pipeline 2 includes a harvesting pipeline 201, a reducing joint 202, and a conveying pipeline 203; wherein, the first end of the harvesting pipeline 201 is detachably and sealed to the end of the harvesting head 1; the end of the harvesting pipeline 201 is sealed to the small-diameter end of the reducing joint 202, and the large-diameter end of the reducing joint 202 is sealed and fixed to the first end of the conveying pipeline 203; the end of the conveying pipeline 203 is detachably connected to the inlet of the collection box 3.

[0009] Specifically, the collection box 3 includes a box body, a separation ramp 301, and a door latch 303. The separation ramp 301 is inclinedly arranged inside the box body. The feed inlet and the discharge outlet 304 are respectively located on two opposite side walls of the box body. The height of the side of the separation ramp 301 near the feed inlet is lower than the height of the side near the discharge outlet 304, thus forming an inclined surface that gradually rises from the feed end to the impeller end. A preset gap is maintained between the end of the separation ramp 301 near the feed inlet and the side wall where the feed inlet is located. The end of the separation ramp 301 near the discharge outlet 304 is seamlessly fitted and fixed to the side wall where the discharge outlet 304 is located. The collection area 302 is located below the separation ramp 301. The door latch 303 is installed on the back of the collection box 3 and is used to open or close the door on the rear side of the collection box 3.

[0010] Specifically, the fan 4 includes an impeller 401, a volute 402, a filter 403, and a built-in motor 404; wherein, the impeller 401 and the built-in motor 404 are fixedly installed in the internal cavity of the volute 402, and the air inlet of the impeller 401 faces the side of the collection box 3, and the built-in motor 404 is installed at the rear end of the impeller 401 and the two are connected; the filter 403 is detachably fixed at the air inlet of the impeller 401, so that the filter 403 is located between the impeller 401 and the discharge port 304 and the filter 403 covers the air inlet.

[0011] Preferably, the picking head 1 is constructed as a flexible picking head, which is made entirely or partially of an elastic material; the size of the opening and the shape of the internal flow channel of the picking head 1 are determined according to the negative pressure range required for selective picking: the negative pressure value must be sufficient to overcome the binding force between mature red fruit and bad fruit and the fruit stalk, while not being sufficient to suck down green fruit with a larger binding force.

[0012] Preferably, the first end of the harvesting pipe 201 is connected to the end of the harvesting head 1 by an interference fit; the end of the harvesting pipe 201 is connected to the small diameter end of the reducing joint 202 by a plug-in connection; the large diameter end of the reducing joint 202 is connected to the first end of the conveying pipe 203 by a plug-in connection and fixed with adhesive; the end of the conveying pipe 203 is detachably connected to the inlet of the collection box 3 by a plug-in connection.

[0013] Preferably, the harvesting pipe 201 in the pipeline 2 is a smooth plastic rigid pipe; the conveying pipe 203 is a flexible pipe made of a smooth material.

[0014] Preferably, the inclination angle of the separation slope 301 relative to the horizontal plane is configured to a preset angle range, which satisfies the following conditions: allowing mature red fruits to roll down the surface of the separation slope 301 under the action of their own gravity, while causing unripe and rotten fruits to be unable to remain stably on the separation slope 301 due to the greater friction with the slope surface, thus moving preferentially towards the discharge port 304 under the action of airflow; the height of the end of the separation slope 301 near the discharge port 304 is not lower than the lower edge of the discharge port 304 and not higher than the upper edge of the discharge port 304.

[0015] Preferably, the impeller 401 is a centrifugal impeller, and the built-in motor 404 is a DC brushless motor powered by a built-in rechargeable battery. The airflow speed generated by the impeller 401 is configured to simultaneously satisfy: a first suction force is generated at the picking head 1, which is greater than the separation force of the stems of red and bad fruits and less than the separation force of the stems of green fruits; and a second suction force is generated at the separation slope 301, which is sufficient to discharge the bad fruits that fall on the separation slope 301 through the discharge port 304, while the red fruits roll down the separation slope 301 to the collection area 302 by gravity.

[0016] Preferably, the shoulder strap 5 includes a left shoulder strap and a right shoulder strap; wherein, the upper ends of the left shoulder strap and the right shoulder strap are respectively fixedly connected to the left and right sides of the back of the collection box 3 near the top position, and the lower ends of the left shoulder strap and the right shoulder strap are respectively fixedly connected to the left and right sides of the back of the collection box 3 near the bottom position, so that the left shoulder strap and the right shoulder strap are symmetrically distributed; both the left shoulder strap and the right shoulder strap are made of flexible woven tape or webbing material.

[0017] The beneficial effects of this invention are: 1. This invention enables selective harvesting based on fruit maturity, significantly improving the quality of fresh coffee. By precisely configuring the speed of the DC brushless motor and the airflow of the centrifugal impeller, combined with the small-diameter suction section of the harvesting pipe, a stable and controllable initial suction force is generated at the flexible harvesting head. Through theoretical calculations and field trials, this initial suction force is set to be greater than the separation force between mature red berries and damaged berries (such as moldy, insect-damaged, or shrunken berries) and their stems, while being less than the separation force between unripe berries and their stems. When the operator brings the flexible harvesting head close to the coffee fruit cluster, red and damaged berries are rapidly sucked into the pipe under negative pressure, while unripe berries, due to insufficient suction to overcome their stem binding force, remain on the branch to continue growing. This design overcomes the technical bottleneck of traditional pneumatic harvesters that cannot distinguish fruit maturity, truly achieving selective harvesting of "red berries, green berries," avoiding subsequent processing quality degradation caused by mixed harvesting of green berries, and significantly improving the overall marketability and economic value of fresh coffee.

[0018] 2. This invention features a fruit separation ramp inside the collection box, utilizing the combined effect of the airflow drag generated by the impeller and the fruit's own weight to achieve immediate separation of red and damaged fruit. Specifically, red fruit, being heavier, has a gravity component that, when applied downwards along the ramp, is sufficient to overcome the friction on the ramp surface and the reverse airflow drag generated by the impeller. Therefore, red fruit automatically rolls down to the collection area below due to gravity. Damaged fruit, being lighter, irregularly shaped, and having poor surface adhesion, cannot remain stably on the ramp surface under the influence of the airflow. It is directly sucked into the impeller inlet, blocked by the filter, slides down the inner wall of the volute, and is finally discharged from the volute outlet. This process completes grading and impurity removal simultaneously with harvesting, eliminating the need for manual sorting or additional grading equipment. This effectively prevents mold contamination and quality deterioration caused by the accumulation of damaged and good fruit, significantly reducing post-harvest losses.

[0019] 3. This invention employs a variable-diameter structure combining harvesting and conveying pipes. The shorter, smaller-diameter suction section achieves a higher airflow velocity at the same air volume, thus generating sufficient suction at the harvesting head while reducing airflow resistance losses. The longer, larger-diameter conveying section, as the fruit enters through the variable-diameter connector, naturally reduces the airflow velocity, slowing the fruit's movement and significantly decreasing the kinetic energy of the collision between the fruit and the pipe wall. Compared to traditional constant-diameter pipes, this variable-diameter design significantly reduces the violent impacts between fruits and between fruits and the pipe wall, effectively lowering the peel and pulp damage rates. It is particularly suitable for high-quality harvesting of coffee cherries with thin, delicate skins that are sensitive to mechanical damage. Furthermore, the reducing joint also plays a crucial role in airflow velocity grading and screening: by precisely designing the cross-sectional ratio and transition curve at the reducing point, the high-speed airflow within the smaller diameter section is sufficient to remove mature red fruits and lighter, damaged fruits such as those affected by insects or mold from the branches. Meanwhile, immature green fruits, due to their stronger bond with the branches and greater weight, can remain on the tree and continue growing under this wind speed. This wind speed differentiation function enables initial grading during harvesting, reducing the mixing of green fruits at the source. This improves the overall consistency of fresh fruit maturity and avoids the waste of green fruits from ineffective harvesting, further enhancing the intelligent and refined harvesting advantages of this invention.

[0020] 4. This invention symmetrically secures the collection box to the operator's back using shoulder straps, keeping the machine's center of gravity close to the spine, allowing for flexible and unrestricted movement during walking, turning, and climbing, without the need for additional pushing or pulling. The conveying pipe uses a smooth plastic hose (such as PU or PE material), offering excellent flexibility and allowing it to bend, twist, and extend freely with the operator's arm and body movements, fundamentally eliminating the constraints of rigid pipes on the operator's posture. A non-slip textured handle is installed above the harvesting pipe, allowing the operator to hold it with one hand and flexibly adjust the angle and direction of the harvesting head to accommodate coffee cherry clusters of different heights and orientations. Compared to large vibratory or pneumatic harvesters, this device is small, lightweight, and requires no external power source (powered by a built-in rechargeable battery), making it ideal for coffee plantations in hilly and mountainous areas like Yunnan, where planting areas are scattered, terrain is undulating, and row spacing is narrow, significantly improving the coverage and mobility of harvesting operations. Attached Figure Description

[0021] Figure 1 : A schematic diagram of the overall structure of the present invention; Figure 2 : A side-view perspective view of the three-dimensional structure of the present invention; Figure 3 : Internal structure diagram of the collection box of this invention; Figure 4 : Schematic diagram of the pipeline of this invention; Figure 5 : Schematic diagram of the centrifugal fan of this invention.

[0022] The labels in the diagram are as follows: 1. Harvesting head; 2. Pipeline; 201. Harvesting pipeline; 202. Reducing joint; 203. Conveying pipeline; 3. Collection box; 301. Separation ramp; 302. Collection area; 303. Box door latch; 304. Waste discharge port; 4. Fan; 401. Impeller; 402. Volute; 403. Filter screen; 404. Built-in motor; 5. Shoulder strap; 6. Handle; 7. Switch. Detailed Implementation

[0023] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0024] Example 1: As Figures 1 to 5 As shown, a backpack-type air-suction coffee cherry selective harvesting and grading integrated machine includes a harvesting head 1, a pipe 2, a collection box 3, a fan 4, a shoulder strap 5, a handle 6, and a switch 7. The shoulder strap 5 and the fan 4 are installed on the outside of the collection box 3. The outlet of the harvesting head 1 is connected to the inlet of the pipe 2. The handle 6 is installed above the pipe 2. The outlet of the pipe 2 is connected to the inlet of the collection box 3. The fan 4 is installed on the outside of the side wall opposite to the inlet of the collection box 3. The switch 7 connected to the fan 4 is installed at the lower end of the fan 4 and is used to control the start and stop of the fan 4. The air inlet of the fan 4 is connected to the airflow channel inside the collection box 3. The shoulder strap 5 is connected to the front end of the collection box 3.

[0025] Furthermore, the pipeline 2 includes a harvesting pipeline 201, a reducing joint 202, and a conveying pipeline 203. The head of the harvesting pipeline 201 is detachably and tightly connected to the end of the harvesting head 1 via an interference fit. This detachable connection facilitates the replacement of harvesting heads of different sizes or shapes according to different varieties or tree shapes, and also facilitates cleaning and maintenance. Specifically, the inner diameter of the end interface of the harvesting head 1 is slightly smaller than the outer diameter of the head of the harvesting pipeline 201. The radial extrusion force generated by the elastic deformation of the material firmly joins the two, ensuring airtightness and connection strength without the need for additional fasteners. The end of the harvesting pipeline 201 is sealed to the small-diameter end of the reducing joint 202 via a plug-in connection. The large-diameter end of the reducing joint 202 is plugged into the head of the conveying pipeline 203 and fixed with adhesive, thereby achieving reliable connection between pipelines of different diameters and materials, forming a complete negative pressure airflow channel. The end of the conveying pipeline 203 is detachably connected to the inlet of the collection box 3 via a plug-in connection, facilitating pipeline assembly and maintenance. The inner diameter of the harvesting pipe 201 is smaller than the inner diameter of the conveying pipe 203, thereby creating a higher airflow velocity at the suction port of the flexible harvesting head 1 and in the small-diameter harvesting pipe 201, and a lower airflow velocity in the large-diameter conveying pipe 203.

[0026] The reducing fitting 202 is injection molded as a single piece. Its smaller diameter end has an inner diameter that matches the outer diameter of the receiving pipe 201, while its larger diameter end matches the outer diameter of the conveying pipe 203. During assembly, they are inserted separately and secured airtightly using adhesive. The reducing fitting 202's function is to achieve a smooth transition in pipe diameter while ensuring airflow continuity, avoiding eddies and energy loss caused by abrupt changes in cross-section. It also serves as a connector between pipes of different materials, facilitating reliable connections between rigid and flexible pipes.

[0027] The handle 6 is fixedly connected to the upper part of the harvesting pipe 201 and has a straight handle structure, allowing the operator to hold it with one hand. Specifically, the handle 6 can be made of injection molding and fixed to the outer wall of the harvesting pipe 201 near the front end through an integral molding process. By holding the handle 6 and using the traction force transmitted by the rear conveying pipe 203, the operator can flexibly adjust the harvesting direction and angle of the harvesting head 1 to adapt to coffee cherry clusters at different heights and positions. The handle 6 can also include a non-slip texture or a rubber coating to improve grip comfort and operational stability.

[0028] Further, the collection box 3 includes a box body, a separation ramp 301, and a door lock 303; wherein, the separation ramp 301 is inclinedly arranged inside the box body, and the feed inlet and the discharge outlet 304 are respectively located on two opposite side walls of the box body. The height of the side of the separation ramp 301 near the feed inlet is lower than the height of the side near the discharge outlet 304, thus forming an inclined surface that gradually rises from the feed end to the impeller end; a preset gap is maintained between the end of the separation ramp 301 near the feed inlet and the side wall where the feed inlet is located. This gap forms a fruit drop channel, which facilitates the coffee fruit to fall into the collection area 302 under the action of gravity; the end of the separation ramp 301 near the discharge outlet 304 is seamlessly fitted and fixed to the side wall where the discharge outlet 304 is located by welding, so as to prevent damaged fruit from falling into the collection area 302 during the process of entering the volute 402 from the discharge outlet 304; the collection area 302 is located below the separation ramp 301 and is used to hold the separated red fruit.

[0029] Furthermore, the rear end of the collection box 3 is provided with a door, and the door is provided with a door latch 303. The door latch 303 is used to achieve an openable and closable locking connection between the door and the collection box body. During the harvesting operation, the door is locked and fixed, and after the harvesting is completed, the door can be unlocked to open the door and take out the fruit in the collection area 302. Specifically, two parallel cylindrical pins are fixedly provided on the movable side of the door; a manually movable latch lever is installed at the corresponding position on the box body. The lever has an opening groove that matches the pin. When closing the door, the operator pushes the door closed, so that the two pins are respectively inserted into the opening of the corresponding groove. Then, the lever is moved to the locked position. At this time, the lever maintains the locked state under its own weight or static friction with the box body. The opening direction of the groove is offset from the withdrawal direction of the pin. The pin is geometrically blocked by the lever or the box structure and cannot be dislodged in the opening direction, thereby achieving a reliable lock between the door and the box body. To open the door, the operator reverses the lever to the open position, aligning the slot opening with the direction the pin is withdrawing. Then, the operator can pull the pin or the handle on the door outwards to open the door. This locking mechanism is simple in structure, intuitive to operate, and highly reliable, making it particularly suitable for field environments with frequent opening and closing operations.

[0030] Furthermore, the fan 4 provides all the air volume and pressure required for the entire system, and is driven by a DC brushless motor. The fan 4 includes an impeller 401, a volute 402, a filter 403, and a built-in motor 404; wherein, the impeller 401 and the built-in motor 404 are fixedly installed in the internal cavity of the volute 402, and the air inlet of the impeller 401 faces the collection box 3, the built-in motor 404 is installed at the rear end of the impeller 401 and the two are connected, and the built-in motor 404 provides power to the impeller 401; the filter 403 is detachably fixed to the air inlet of the impeller 401 with screws, so that the filter 403 is located between the impeller 401 and the discharge port 304 and covers the air inlet, which can effectively prevent bad fruit from entering the impeller and allow the bad fruit to be discharged from the discharge port of the volute 402.

[0031] The filter 403 uses a metal wire mesh or plastic grid structure, with the mesh diameter designed to be smaller than the diameter of the smallest damaged fruit. This ensures that when the airflow carrying fruit passes through the air inlet, damaged fruit is blocked by the filter 403 and cannot enter the impeller 401. During operation, the airflow carrying damaged fruit enters the volute 402 through the discharge port 304 of the collection box 3. Due to their soft texture or small size, damaged fruit may break or bounce after impacting the filter 403, and then slide down the inner wall of the volute 402 under the action of gravity and air drag, eventually being discharged from the bottom of the volute 402. This structure effectively protects the impeller 401 from damage caused by fruit impact, while simultaneously achieving automatic separation and discharge of damaged fruit from the airflow.

[0032] Furthermore, the harvesting head 1 is constructed as a flexible harvesting head, which is made entirely or partially of an elastic material, capable of adaptive deformation upon contact with coffee berries to avoid mechanical damage to the berries and improve the harvesting success rate. In this embodiment, the harvesting head 1 is integrally injection molded from food-grade silicone or thermoplastic elastomer (TPE), with its front end designed as a trumpet-shaped or petal-shaped structure, hollow inside and communicating with the inner cavity of the harvesting pipe 201, to avoid scratching the coffee berry skin or damaging the branches during harvesting. The opening size and internal flow channel shape of the harvesting head 1 are determined according to the negative pressure range required for selective harvesting: this negative pressure value must be sufficient to overcome the binding force between mature red berries and damaged berries and the stalk, while being insufficient to suck down green berries with greater binding force.

[0033] Furthermore, the harvesting pipe 201 in the pipeline 2 is made of smooth plastic rigid pipe. The inner wall surface of the rigid pipe is smooth to minimize airflow resistance and friction loss when the fruit passes through. At the same time, its pipe body has sufficient radial stiffness and compressive strength, and is not easily deformed or flattened during the carrying operation, so as to maintain the stability of the pipe shape during the harvesting process. The conveying pipe 203 is made of smooth material and is also smooth on the inner wall. The pipe body has good flexibility. The flexible pipe can bend and deform according to the operator's carrying posture and picking action, avoiding the restriction of the operator's movement by the rigid pipe, thereby significantly improving the flexibility and comfort of the picking operation.

[0034] Furthermore, the inclination angle of the separation slope 301 relative to the horizontal plane is configured within a preset angle range, which satisfies the following conditions: allowing mature red fruits to roll down the surface of the separation slope 301 under the action of their own gravity, while causing unripe and damaged fruits to be unable to remain stably on the separation slope 301 due to the greater friction with the slope surface, thus allowing them to move preferentially towards the discharge port 304 under the action of airflow; the height of the end of the separation slope 301 near the discharge port 304 matches the opening height of the discharge port 304, specifically, the height of this end is not lower than the lower edge of the discharge port 304 and not higher than the upper edge of the discharge port 304, to prevent the fruits from directly hitting the side wall of the collection box 3 after detaching from the end of the slope, causing rebound or accumulation, and ensuring that the fruits can smoothly enter the volute 402 through the discharge port 304 and be finally discharged.

[0035] Furthermore, the impeller 401 is a centrifugal impeller, and the built-in motor 404 is a DC brushless motor powered by a built-in rechargeable battery. The airflow velocity generated by the impeller 401 is configured to simultaneously satisfy: a first suction force is generated at the picking head 1, which is greater than the separation force of the stems of red and bad fruits and less than the separation force of the stems of green fruits; and a second suction force is generated at the separation slope 301, which is sufficient to discharge the bad fruits that fall on the separation slope 301 through the discharge port 304, while the red fruits roll down the separation slope 301 to the collection area 302 by gravity.

[0036] Furthermore, the carrying strap 5 includes a left shoulder strap and a right shoulder strap; wherein, the upper ends of the left shoulder strap and the right shoulder strap are respectively fixedly connected to the left and right sides of the back of the collection box 3 near the top position, and the lower ends of the left shoulder strap and the right shoulder strap are respectively fixedly connected to the left and right sides of the back of the collection box 3 near the bottom position, so that the left shoulder strap and the right shoulder strap are symmetrically distributed; both the left shoulder strap and the right shoulder strap are made of flexible woven strap or webbing material, which has a certain tensile strength and wear resistance, and are used to carry the collection box 3 on the operator's shoulders, so as to realize the carrying and movement of the whole machine.

[0037] The working process of this embodiment is described in detail below.

[0038] The operator slings the shoulder strap 5 over their shoulder, positioning the collection box 3 on their back, freeing their hands. Holding the handle 6 above the harvesting pipe 201 with one hand, the operator aligns the harvesting head 1 with the coffee cherries on the coffee branches. With the other hand, the operator presses the control switch 7 on the left side of the collection box 3 to start the blower 4. The blower 4 begins to draw air, following the following airflow path: outside air enters through the flexible nozzle of the harvesting head 1, flows sequentially through the harvesting pipe 201, the reducer 202, and the conveying pipe 203, and enters the inner cavity of the collection box 3.

[0039] In this airflow path, due to the small diameter of the harvesting pipe 201, a relatively high initial wind speed is generated within it. This initial wind speed produces an initial suction force at the suction nozzle of the harvesting head 1. After testing and configuration, the magnitude of this initial suction force is set to be greater than the separation force between red and damaged fruits (such as moldy, insect-damaged, or shriveled fruits) and the fruit stalk, and less than the separation force between green fruits and the fruit stalk. Therefore, when the suction nozzle approaches the fruit bunch, red and damaged fruits are sucked into the harvesting pipe 201, while green fruits, due to insufficient suction to overcome the separation force of their fruit stalks, are left on the tree to continue growing.

[0040] The sucked-in red and damaged fruits are carried by the airflow into the harvesting pipe 201, and after passing through the reducing joint 202, they enter the larger diameter conveying pipe 203. Due to the sudden increase in pipe diameter, the airflow speed decreases, the secondary wind speed decreases, and the movement speed of the fruits slows down accordingly. This effectively reduces collision damage between fruits and between fruits and the pipe wall, and also prevents red fruits from being discharged directly from the discharge port due to inertia because of excessive speed.

[0041] Subsequently, the fruit falls into the collection box 3 and then onto the separation slope 301. On the separation slope 301, the red fruit, due to its greater mass, experiences a greater downward component of its gravity than the frictional force from the slope and the drag force provided by the impeller. Therefore, the red fruit automatically rolls down the separation slope 301 under its own weight and eventually falls into the fruit collection area 302 below. The damaged fruit, due to its lighter mass, experiences a smaller downward component of its gravity and is also affected by the suction airflow at the impeller 401. It cannot remain stably on the slope 301 and is sucked by the airflow from the fan 4 to the outlet of the volute 402 and discharged from the collection box 3, thus achieving immediate separation of the red and damaged fruit.

[0042] After completing a single harvest, the operator can move the harvesting head 1 to the next bunch of fruit and repeat the process. When the collection container is full of red fruit, the door of the collection box 3 can be opened through the door lock 303 to take out the collected red fruit for transfer.

[0043] The specific embodiments of the present invention have been described in detail above. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

Claims

1. A backpack-mounted, air-suction type coffee cherry selective harvesting and grading integrated machine, characterized in that, It includes a picking head (1), a pipe (2), a collection box (3), a fan (4), a shoulder strap (5), a handle (6), and a switch (7); wherein, the discharge port of the picking head (1) is connected to the inlet end of the pipe (2), the handle (6) is installed above the pipe (2), the outlet end of the pipe (2) is connected to the inlet of the collection box (3), the fan (4) is installed on the outside of the side wall opposite to the inlet of the collection box (3), the switch (7) connected to the fan (4) is installed at the lower end of the fan (4), the air intake of the fan (4) is connected to the airflow channel inside the collection box (3), and the shoulder strap (5) is connected to the front end of the collection box (3).

2. The backpack-mounted air-suction type coffee cherry selective harvesting and grading integrated machine according to claim 1, characterized in that, The pipeline (2) includes a harvesting pipeline (201), a reducing joint (202), and a conveying pipeline (203); wherein, the first end of the harvesting pipeline (201) is detachably connected to the end of the harvesting head (1); the end of the harvesting pipeline (201) is sealed to the small diameter end of the reducing joint (202), and the large diameter end of the reducing joint (202) is sealed and fixed to the first end of the conveying pipeline (203); the end of the conveying pipeline (203) is detachably connected to the inlet of the collection box (3).

3. The backpack-mounted air-suction type coffee cherry selective harvesting and grading integrated machine according to claim 1, characterized in that, The collection box (3) includes a box body, a separation ramp (301), and a door latch (303); wherein, the separation ramp (301) is inclinedly arranged inside the box body, and the feed inlet and the discharge outlet (304) are respectively located on two opposite side walls of the box body. The height of the side of the separation ramp (301) near the feed inlet is lower than the height of the side near the discharge outlet (304), thereby forming an inclined surface that gradually rises from the feed end to the impeller end; a preset gap is maintained between the end of the separation ramp (301) near the feed inlet and the side wall where the feed inlet is located; the end of the separation ramp (301) near the discharge outlet (304) is seamlessly fitted and fixed to the side wall where the discharge outlet (304) is located; the collection area (302) is located below the separation ramp (301); the door latch (303) is installed on the back of the collection box (3) and is used to open or close the door on the back side of the collection box (3).

4. The backpack-mounted air-suction type coffee cherry selective harvesting and grading integrated machine according to claim 1, characterized in that, The fan (4) includes an impeller (401), a volute (402), a filter (403), and a built-in motor (404); wherein the impeller (401) and the built-in motor (404) are fixedly installed in the internal cavity of the volute (402), and the air inlet of the impeller (401) faces the side of the collection box (3), and the built-in motor (404) is installed at the rear end of the impeller (401) and the two are connected; the filter (403) is detachably fixed at the air inlet of the impeller (401), so that the filter (403) is located between the impeller (401) and the discharge port (304) and the filter (403) covers the air inlet.

5. The backpack-mounted air-suction type coffee cherry selective harvesting and grading integrated machine according to claim 1, characterized in that, The picking head (1) is constructed as a flexible picking head, which is made of elastic material in whole or in part; the size of the opening and the shape of the internal flow channel of the picking head (1) are determined according to the negative pressure range required for selective picking: the negative pressure value must be sufficient to overcome the binding force between the mature red fruit and the bad fruit and the fruit stalk, while not enough to suck down the green fruit with a larger binding force.

6. The backpack-mounted air-suction type coffee cherry selective harvesting and grading integrated machine according to claim 2, characterized in that, The first end of the harvesting pipe (201) is detachably connected to the end of the harvesting head (1) by an interference fit; the end of the harvesting pipe (201) is sealed to the small diameter end of the reducing joint (202) by a plug-in connection; the large diameter end of the reducing joint (202) is plugged to the first end of the conveying pipe (203) and fixed with adhesive; the end of the conveying pipe (203) is detachably connected to the inlet of the collection box (3) by a plug-in connection.

7. The backpack-mounted air-suction type coffee cherry selective harvesting and grading integrated machine according to claim 2, characterized in that, The harvesting pipe (201) in the pipeline (2) is made of smooth plastic rigid pipe; the conveying pipe (203) is made of smooth material flexible hose.

8. The backpack-mounted air-suction type coffee cherry selective harvesting and grading integrated machine according to claim 3, characterized in that, The inclination angle of the separation slope (301) relative to the horizontal plane is configured to a preset angle range, which satisfies the following conditions: the mature red fruit can roll down the surface of the separation slope (301) under the action of its own gravity component, while the immature bad fruit cannot stay stably on the separation slope (301) due to the large friction with the slope surface, so it moves preferentially towards the discharge port (304) under the action of airflow; the height position of the end of the separation slope (301) near the discharge port (304) is not lower than the lower edge of the discharge port (304) and not higher than the upper edge of the discharge port (304).

9. The backpack-type air-suction coffee cherry selective harvesting and grading integrated machine according to claim 4, characterized in that, The impeller (401) is a centrifugal impeller, and the built-in motor (404) is a DC brushless motor powered by a built-in rechargeable battery. The airflow speed generated by the impeller (401) is configured to simultaneously satisfy: a first suction force is generated at the picking head (1), which is greater than the separation force of the stems of red fruit and bad fruit and less than the separation force of the stems of green fruit, and a second suction force is generated at the separation slope (301), which is sufficient to discharge the bad fruit that falls on the separation slope (301) through the discharge port (304), while the red fruit rolls down the separation slope (301) to the collection area (302) by gravity.

10. The backpack-mounted air-suction type coffee cherry selective harvesting and grading integrated machine according to claim 1, characterized in that, The shoulder strap (5) includes a left shoulder strap and a right shoulder strap; wherein, the upper ends of the left shoulder strap and the right shoulder strap are respectively fixedly connected to the left and right sides of the back of the collection box (3) near the top position, and the lower ends of the left shoulder strap and the right shoulder strap are respectively fixedly connected to the left and right sides of the back of the collection box (3) near the bottom position, so that the left shoulder strap and the right shoulder strap are symmetrically distributed; the left shoulder strap and the right shoulder strap are both made of flexible woven tape or webbing material.

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