Shearing and harvesting device for cluster-shaped fruits

Abstract

The invention relates to the field of fruit and vegetable picking devices, and discloses a clustered fruit shearing and harvesting device which comprises a mounting main body, a fixed tooth row, a movable tooth row, a driving mechanism, a transmission assembly, a guide assembly, a resistance reduction assembly and an anti-movement assembly, and the mounting main body is provided with a supporting arm; the fixed tooth row is fixedly connected to the supporting arm of the mounting main body; the movable tooth row is in sliding fit with the fixed tooth row through a guide assembly, the movable tooth row and the fixed tooth row are each of a multi-tooth dense structure, the tooth root of a single tooth is wide, and the tooth tip of the single tooth is narrow. The driving mechanism is installed on the installation body and drives the movable tooth row to do reciprocating shearing motion relative to the fixed tooth row through a transmission assembly. The guide assembly comprises a guide piece arranged on the movable tooth row and a guide groove formed in the fixed tooth row, a guide structure is arranged on one side of the guide piece, and the guide structure is matched with the guide groove for guiding; the resistance reduction assembly is embedded in the mounting groove of the fixed tooth row, so that a preset gap is formed between the movable tooth row and the fixed tooth row, and the preset gap can be adjusted by replacing the resistance reduction assemblies with different thicknesses; the anti-movement assembly is arranged between the installation body and the fixed tooth row and used for pressing the movable tooth row to prevent the movable tooth row from vertically moving and falling off. The device has the advantages of being stable in shearing, high in operation error-tolerant rate, convenient to maintain, high in adaptability and the like, and can be effectively used for manual and automatic harvesting of cluster-shaped fruits such as cherries.

Description

Technical Field

[0001] This invention relates to the field of fruit and vegetable harvesting devices, and particularly to a cutting and harvesting device for clustered fruits. Background Technology

[0002] Harvesting clustered fruits such as cherries, goji berries, and blueberries still relies heavily on manual labor, resulting in low efficiency, high labor intensity, and high labor costs. Existing technologies have proposed various mechanized harvesting solutions, among which shearing harvesting devices have been widely studied due to their minimal damage to the fruit and broad applicability.

[0003] Currently, although the publicly disclosed push-shear harvesting devices (such as those shown in patent ZL202110004422.6) have initially achieved mechanical harvesting functions, they still have several technical defects in practical applications, which restrict their promotion and practical application:

[0004] Firstly, the tooth structure is unreasonable, resulting in poor guidance of the fruit stalk and poor shearing stability. Existing devices often use a straight tooth structure with equal width at the tips and roots of the moving and fixed blades. The fruit stalk is not easily guided naturally between the teeth and is easily blocked by the wide tooth tips. When multiple fruit stalks enter the space between the teeth at the same time, the shearing force is prone to a step-like change, which can impact the drive motor and easily cause jamming or overload failures.

[0005] Secondly, high precision is required for centering, making remote operation difficult. To simplify the structure, existing solutions often employ a design with fewer teeth, which requires the device to be precisely aligned with the fruit stem for effective cutting. When the device is installed on a handheld long pole or at the end of a robotic arm for high-altitude or remote operations, operational vibrations or end-effector positioning errors make precise centering difficult, increasing the operational difficulty and workload.

[0006] Third, the guiding and driving structures have mechanical defects, making them prone to wear and jamming. Existing devices often use single- or double-sided guide rails, with the driving point close to the rail. This layout results in a significant difference between the driving force arm and the shear resistance arm. The torque generated by the driving force and the shear resistance torque are superimposed in direction, forming an eccentric torque, which exacerbates the uneven wear and tear of the guide rail, easily causing movement jamming. The guide rail structure is complex, replacement costs are high, and maintenance is inconvenient.

[0007] Fourth, the cutting mechanism is simplistic, making it prone to "severed threads" and blade wear. Existing solutions mostly employ a design with two straight blades cutting in parallel, relying primarily on compression and shearing for fruit stems rich in pectin and fiber. This easily leads to stem deformation and fiber pulling, often resulting in incomplete cuts. Furthermore, if the two blades are in direct contact, friction generates significant heat, accelerating blade wear; if a gap is left, incomplete cutting is likely. Existing patents do not provide a clear and effective solution.

[0008] In summary, existing shearing and harvesting devices for clustered fruits still have significant shortcomings in terms of tooth design, mechanical stability, operational adaptability, and cutting reliability. Therefore, there is an urgent need for a new type of shearing and harvesting device that can achieve stable introduction, orderly shearing, reliable cutting, and low-resistance movement of the fruit stalk in complex operating environments, while also possessing good operability and ease of maintenance, to meet the diverse needs of manual, semi-automatic, and automated harvesting. Summary of the Invention

[0009] To address the aforementioned technical problems, this invention provides a cluster fruit cutting and harvesting device to achieve efficient, stable, and reliable cutting and harvesting of cluster fruits, while significantly reducing operational difficulty and equipment maintenance costs.

[0010] To achieve the above objectives, the technical solution of the present invention is as follows:

[0011] A clustered fruit cutting and harvesting device includes an installation body, a fixed toothed row, a movable toothed row, a drive mechanism, a transmission component, a guide component, a drag reduction component, and an anti-slip component;

[0012] The mounting body includes a cantilever beam support arm; a fixed toothed rack fixedly connected to the cantilever beam support arm of the mounting body; a movable toothed rack slidingly engaged with the fixed toothed rack via a guide assembly; both the movable and fixed toothed racks have a multi-tooth densely distributed structure, with wide root and narrow tip of each tooth, preferably triangular in cross-section, but also potentially triangular or trapezoidal, and double-edged teeth; a drive mechanism mounted on the mounting body, which drives the movable toothed rack to perform reciprocating shearing motion relative to the fixed toothed rack via a transmission assembly; and a guide assembly. It includes a guide plate disposed on the movable toothed rack and a guide groove disposed on the fixed toothed rack. The guide plate has a guide structure on one side, which cooperates with the U-shaped guide groove for guidance; a drag-reducing component, which is embedded in the mounting groove of the fixed toothed rack to form a preset gap between the movable toothed rack and the fixed toothed rack. The preset gap can be adjusted by replacing drag-reducing components of different thicknesses; and an anti-movement component, which is disposed between the mounting body and the fixed toothed rack to press the movable toothed rack to prevent it from moving vertically and falling off.

[0013] In the above scheme, the transmission component includes an eccentric wheel and a connecting rod, the drive mechanism is a high-torque servo, the eccentric wheel is mounted on the servo shaft, its eccentric radius is half the tooth spacing of the moving tooth row, the two ends of the connecting rod are respectively hinged to the eccentric wheel and the moving tooth row, and the hinge point is located in the middle of the width of the moving tooth row near the tooth root.

[0014] In the above scheme, the guide component is a guide plate, which is made of self-lubricating non-metallic material or metal material with a self-lubricating coating on the surface, and is detachably connected to the moving gear row by screws; the guide groove is a U-shaped groove with a semi-cylindrical bottom and its radius is slightly larger than the semi-cylindrical diameter of the guide structure.

[0015] In the above scheme, the drag reduction component adopts a drag reduction plate, which is interference-fitted into the mounting groove of the fixed tooth row, with both ends fixed, and the height of the drag reduction plate is higher than the height of the mounting groove.

[0016] In the above scheme, the anti-slip component is an elastic pressure plate, which has an L-shaped structure and there are no fewer than two of them; the lateral extension of the elastic pressure plate is inclined downward at an angle of 10° to 20° with the horizontal plane, and its end edge is rounded; the vertical side of the elastic pressure plate is provided with a long groove, and is fixed to the mounting body by a vertical connector and a horizontal connector, and the clamping force can be finely adjusted by adjusting the height of the vertical connector.

[0017] In the above scheme, the moving tooth row and the fixed tooth row are made of high carbon steel, and the bottom plane of their tooth edges is coated with PTFE self-lubricating coating; the elastic pressure plate is made of spring steel; the mounting body, the guide plate and the drag-reducing plate are made of glass fiber reinforced nylon.

[0018] In the above scheme, the tooth edge surface of the moving tooth row is provided with anti-slip grooves or micro-tooth structures.

[0019] In a further technical solution, the bottom of the support arm of the mounting body is provided with reinforcing ribs, and its end is provided with a mounting frame for mounting the drive mechanism; the outer side wall of the mounting frame is provided with a connection structure for connecting a handheld rod, a grip handle, or a mechanical arm end mounting interface.

[0020] A further technical solution also includes a handheld extension rod, an image acquisition device, a display device, and a rotating mechanism. The rotating mechanism is located between the mounting frame and the end of the handheld rod or robotic arm, and is used to drive the shearing and harvesting device to rotate around its axis to adjust the shearing orientation.

[0021] In a further technical solution, the handheld extension rod is connected to the back of the mounting frame, the camera is mounted on the top of the handheld extension rod, and the display screen is mounted near the gripping part of the handheld extension rod to display the images captured by the camera.

[0022] The clustered fruit cutting and harvesting device provided by the present invention, through the above technical solution, has the following beneficial effects:

[0023] 1. Smooth Guiding and Smooth Shearing Force: By employing a triangular or trapezoidal close-tooth structure with wide root and narrow tip, a gradually changing tooth gap with a large opening and narrow root is formed. This structure can efficiently guide the fruit stalk naturally into the tooth gap and utilize its gradually converging characteristics to achieve "sequential shearing" of randomly distributed fruit stalks, avoiding the load impact when shearing multiple fruit stalks simultaneously, effectively protecting the drive motor, and improving the stability of operation and the life of the equipment.

[0024] 2. Adaptive clamping, reliable anti-slip mechanism: Combining the self-tightening force generated during triangular toothed shearing with the active downward pressure of the adjustable elastic pressure plate, a dual anti-slip mechanism of "mechanical self-tightening + elastic clamping" is formed. This design ensures that the moving toothed row can fit tightly with the fixed toothed row in various working postures, without the risk of lifting or falling off. At the same time, the clamping force is adjustable to adapt to different working conditions.

[0025] 3. Composite Cutting for Thorough Cutting and Blade Protection: The innovative "shear-cut" composite cutting mechanism, combined with a precisely controllable micro-gap (preferably 5%-10% of the fruit stem diameter), achieves high-low staggered shearing. This quickly breaks through the fruit stem fibers, significantly reducing cutting resistance, while preventing fruit stem compression deformation and "broken but still connected" phenomena. Simultaneously, the double-edged non-contact design avoids frictional heat generation and impact wear, significantly extending blade life.

[0026] 4. Precise guidance, low drag, and easy maintenance: The optimized design of the long-distance guide components at both ends and the centrally located drive point effectively balances the driving torque, significantly reducing eccentric torque and motion jamming. The guide plates and drag-reducing plates, made of self-lubricating materials, further reduce motion resistance and wear. Key wear parts (guide plates and drag-reducing plates) adopt a modular, detachable design, allowing for quick and individual replacement after wear without disassembling the main structure, greatly reducing maintenance costs and operational complexity.

[0027] 5. High operational tolerance and strong adaptability: The densely packed multi-tooth design reduces the stringent requirements for the centering accuracy of individual fruit stalks. Operators only need to ensure that the tooth row covers the fruit stalk area, supporting two efficient operation modes: "insertion cutting" and "sweeping cutting". The device has a lightweight structure and can be adapted to fruit stalks of different diameters by replacing drag-reducing plates of different thicknesses. It has good versatility and expandability, making it easy to integrate into handheld tools or robotic arms, and adaptable to various harvesting scenarios such as manual, semi-automatic, and fully automated harvesting. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below.

[0029] Figure 1 This is an exploded schematic diagram of a clustered fruit shearing and harvesting device disclosed in an embodiment of the present invention;

[0030] Figure 2 This is a view of the device from the tooth root direction.

[0031] Figure 3 This is a view of the device from the direction of the tooth tip;

[0032] Figure 4 A schematic diagram showing the initial positional alignment of the movable and fixed gear racks during installation.

[0033] Figure 5 It is a moving gear structure;

[0034] Figure 6 For fixed toothed rack structure;

[0035] Figure 7 This is a partial schematic diagram of the double-edged oblique edge of the moving gear row;

[0036] Figure 8 This is a partial view of the micro-tooth structure of the moving tooth row;

[0037] Figure 9 This diagram illustrates the microscopic force analysis and force curve changes during the cutting of a single fruit stalk. (a) is a schematic diagram of the area where the last connecting point of the stalk is about to be severed by a beveled blade (the shaded area of ​​an approximate triangle on the right). (b) is a schematic diagram of the area where the last connecting point of the stalk is about to be severed by a straight blade (a micro-region spanning the transverse diameter). (c) is a schematic diagram of the "height" of the micro-shearing surface at the initial contact with the stalk during the beveled blade cutting. (d) is a diagram of the initial contact with the stalk during the straight blade cutting. (e) and (f) are schematic diagrams of the force changes along the cutting direction as the blade advances until the stalk is severed during the entire cutting process.

[0038] Figure 10 The diagrams show the cutting process of a single fruit stem. (a) shows a single-blade oblique cut (the other blade does not cut but only serves as a barrier), (b) shows a single-blade straight cut, (c) shows the distance the blade travels relative to the initial cutting position when cutting with a double-blade oblique cut, and (d) shows the distance the blade travels relative to the initial cutting position when cutting with a double-blade straight cut.

[0039] Figure 11 This is a schematic diagram of an automated harvesting system;

[0040] Figure 12 This is a flowchart of the shearing process;

[0041] Figure 13 Cuttings for a single fruit or a cluster of fruits; (a) is a view along the length of the apparatus, (b) is a top view;

[0042] Figure 14 A schematic diagram of sweeping and cutting fruit clusters on tree branches; (a) is a view along the length of the device, and (b) is a top view;

[0043] Figure 15 (a) is a schematic diagram of a handheld harvesting device; (b) is a schematic diagram of the upper part of the device;

[0044] Figure 16 Diagram showing the addition of a handheld handle;

[0045] Figure 17 This is a schematic diagram of a cross-section combining trapezoidal and triangular tooth shapes.

[0046] Figure 18 This is a schematic diagram of a trapezoidal tooth with equal thickness in cross-section;

[0047] Figure 19 Schematic diagram of the fixed gear designed for lightweight construction;

[0048] Figure 20 This is an assembly diagram showing the effect of the tooth gap.

[0049] In the diagram, 1. Moving gear rack; 2. Fixed gear rack; 3. Connecting rod; 4. Eccentric wheel; 5. Drive servo motor; 6. Mounting body; 7. Elastic pressure plate; 8. Drag reduction plate; 9. Guide plate; 10. Fruit; 11. Fruit stem; 12. Branch; 13. Handheld long pole; 14. Camera; 15. LCD screen; 16. Receiving net; 17. Handheld handle. Detailed Implementation

[0051] 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.

[0052] This invention provides a cutting and harvesting device for clustered fruits, and specific embodiments are as follows:

[0053] Basic structure and working principle

[0054] like Figures 1 to 6 As shown, this embodiment provides a double-row interlocking cluster fruit cutting and harvesting device. Its core components include: a moving tooth row 1, a fixed tooth row 2, a connecting rod 3, an eccentric wheel 4, a drive servo motor 5, a mounting body 6, an elastic pressure plate 7, a drag-reducing plate 8, and a guide plate 9.

[0055] 1. Installation and assembly:

[0056] The mounting body 6 is made of glass fiber reinforced nylon and is L-shaped overall, with a cantilever beam support arm extending from one side. First, the fixed tooth rack 2 is fixed to the cantilever beam support arm with bolts. Both the fixed tooth rack 2 and the movable tooth rack 1 are made of SK5 high-carbon steel sheets, with the surface heat-treated to enhance hardness, and a PTFE self-lubricating coating is sprayed on the shearing blade area in contact with the fruit stem to reduce friction. In this embodiment, both tooth racks contain 10 teeth with a tooth spacing of 8mm and a total length of approximately 80mm. The cross-section of each tooth is triangular, gradually narrowing from the root to the tip.

[0057] like Figure 7 As shown, both the fixed tooth row 2 and the movable tooth row 1 adopt a double-edged oblique blade design. The oblique surfaces on both sides of a single tooth are inclined surfaces. The angle between the oblique surface of the tooth blade section and the bottom surface is θ. This angle can be adjusted according to the material of the fruit stem to be cut, such as the pectin content and the ease of fiber cutting, to adapt to the cutting requirements of different fruit stems. The smaller θ is, the sharper the cutting edge, but the tooth blade strength will be relatively reduced. Conversely, the sharpness of the cutting edge will be relatively reduced, but the tooth blade strength will be enhanced.

[0058] The moving toothed blades have anti-slip grooves or micro-tooth structures on their surfaces to prevent the fruit stalk from sliding along the blades during cutting, ensuring rapid severing of the stalk. For example... Figure 8 As shown, micro-tooth is a common structure on the blades of scissors. Similarly, anti-slip grooves have a similar effect to micro-tooth, accelerating the cutting process. Their structure consists of a series of parallel, small, short, shallow U-shaped grooves or U-shaped grooves arranged perpendicular to the tooth line on the inclined surface of the blade. Anti-slip grooves are a common structure on the blades of scissors. Industry professionals can design micro-tooths and anti-slip grooves using existing technologies, so they will not be elaborated here.

[0059] 2. Guiding and clearance settings:

[0060] At the rear of the movable toothed rack 1, two guide plates 9 made of reinforced nylon are installed with screws. Each guide plate 9 has a semi-cylindrical strip-shaped guide structure on one side. At the corresponding position of the fixed toothed rack 2, two U-shaped guide grooves are machined, the bottom shape of which matches the semi-cylindrical structure of the guide plate 9, and the radius is slightly larger to form a sliding fit. An installation groove is opened on the back of the fixed toothed rack 2, and a drag-reducing plate 8 with a thickness of 1.1mm (also made of reinforced nylon) is pressed into the groove with an interference fit, and a small amount of epoxy resin is applied to both ends for fixation. Since the height of the drag-reducing plate 8 is higher than the installation groove, when the movable toothed rack 1 and the fixed toothed rack 2 are stacked, a preset gap of about 0.1mm is formed between the teeth (suitable for fruit stems with a diameter of about 1mm). This gap can be adjusted by replacing drag-reducing plates 8 with different thicknesses (such as 1.2mm, 1.3mm).

[0061] 3. Drive and Transmission:

[0062] The drive servo 5 (a PWM servo with a 0-180° swing angle) is mounted in the mounting frame at the end of the mounting body 6. The eccentric wheel 4 is mounted on the servo output shaft, and its eccentric radius is designed to be half the tooth pitch (i.e., 4mm). One end of the connecting rod 3 is hinged to the eccentric shaft of the eccentric wheel 4, and the other end is connected to the hinge seat in the middle of the width direction of the moving gear 1. This hinge point is located near the tooth root to minimize the driving torque.

[0063] 4. Clamping mechanism:

[0064] Two L-shaped 65Mn spring steel elastic pressure plates 7 are initially fixed to the mounting body 6 with vertical screws through long grooves on their vertical sides. Their lateral extensions extend downwards at approximately a 15° angle to the horizontal plane, with their ends extending above the tooth root area on the upper surface of the moving tooth rack 1. By tightening the lateral screws, the elastic pressure plates 7 are simultaneously pressed against the mounting body 6 and the fixed tooth rack 2. By finely adjusting the height of the vertical screws, the curvature of the elastic pressure plates 7 can be changed, thereby precisely adjusting their downward pressure on the moving tooth rack 1.

[0065] 5. Work process:

[0066] When the power is turned on, the controller (not shown in the figure) cyclically outputs PWM signals with pulse widths of 500μs and 2500μs, driving the servo motor 5 to oscillate back and forth between 0° and 180°. Through the transmission of the eccentric wheel 4 and the connecting rod 3, the rotational motion of the servo motor is converted into the linear reciprocating motion of the moving gear 1 along the guide plate 9, with a stroke of approximately ±4mm.

[0067] During operation, the opening of the toothed row of the device is positioned parallel to and close to the upper part of the cherry stem. Guided by the large opening between the triangular teeth, the stem naturally slides into the gap. As the moving toothed row 1 reciprocates, its teeth interlock with the teeth of the fixed toothed row 2, shearing the stem. Due to the gap and the cutting action of the oblique blades, the stem is quickly severed and falls into the receiving device below. The elastic pressure plate 7 provides stable clamping force throughout the process, preventing the moving toothed row 1 from tilting upwards under the shearing reaction force.

[0068] Example 1:

[0069] In this embodiment, the blade inclination angle of the double oblique blade, that is, the angle between the blade and the midline of the gap between the two teeth, is 10°~30° (preferably 10°); the stem diameter is based on common cherry stems, generally the stem diameter D is 1mm~2mm, taking into account thin branches, generally up to 5mm. Correspondingly, the tooth spacing of the tooth row is set to 8mm, which is 8-4 times the stem diameter, which can cover all stem sizes and also take into account the 5mm cutting of thin branches.

[0070] Cutting speed The servo motor speed can be controlled to drive the moving gear to reciprocate linearly through the eccentric wheel and connecting rod. The reciprocating speed can be set to 4mm / s~8mm / s, that is, the servo motor swing angle rotation time from 0 to 180° is set to 1-2s. This time can also be flexibly adjusted through the control circuit.

[0071] A comparison of the force analysis of double-beveled cutting (moving tooth cutting edge + fixed tooth cutting edge) and double-straight-edge cutting (moving tooth cutting edge and fixed tooth cutting edge) on the fruit stalk is presented, considering the shearing force of the beveled cutting (the beveled cutting edge actually has both shearing and cutting effects, which can reduce the shearing force). The microscopic local force and shearing force changes are shown in the diagram relative to the double-straight-edge cutting. Figure 9 As shown: the circles in the figures represent the cross-section of the fruit stalk, the two solid lines in each figure represent the shearing blade, and the shaded area in each circle represents the shearing surface cutting the microscopic region. It is the diameter of the fruit stalk. , These refer to the movement distance of the cutting edges for straight-blade cutting and bevel cutting, respectively. It is the inclination angle of the beveled edge (the angle between the center line of the gap between the blade edge and the tooth edge). It is the shearing force along the feed direction during the initial shearing of a beveled cut. It is the initial shear force for straight-blade cutting. Combined with... Figure 9 The change in the microscopic shear area from the start to the end of the cut reveals that the force on the cutting edge manifests as follows: the contact element between the oblique blade and the fruit stalk gradually expands from near the edge close to the stalk diameter on one side to the full height (stalk diameter) and then gradually decreases to 0, severing the stalk. In contrast, the contact element between the straight blade and the stalk instantly covers the full height. The difference in the height of the contact element and the rate of increase in the shear area directly leads to the different shapes of the force curves. Double oblique blade cutting is a progressive shearing, while double straight blade cutting is a symmetrical full-height shearing. Oblique blade cutting has the following advantages over straight blade cutting:

[0072] 1) The peak force of the beveled blade is lower and the rate of force change is smoother, so the instantaneous load requirement of the drive motor is much lower than that of the straight blade.

[0073] When cutting with a straight blade, the initial contact point when the blade edge contacts the fruit stalk is at both ends of the vertical diameter (the vertical diameter of the cross-section), and the cutting surface is a "full-height symmetrical shear surface" (the height of the initial contact micro-surface = the diameter of the fruit stalk). As the blade penetrates, the lateral extension of the contact length of the cutting surface continuously increases (until the blade edge approaches the center), eventually cutting off at the center. This process results in a force curve exhibiting the following shape: "initial high force → rapid increase in peak value and maintenance of stability → slow decrease → rapid drop to 0 (step drop to 0 or drop to 0 with a large slope)". The impact load at the moment of cutting is significant, with a step change.

[0074] When cutting with a beveled blade, the initial contact point when the blade contacts the fruit stem is a point on the circular side near the vertical diameter. At points other than the maximum diameter, the cutting surface is a progressively narrowing shear surface. The width of the contact surface gradually decreases on one side (cutting one side first), while on the other side it initially increases (to the diameter) and then gradually decreases. The final cut is made in a small area near the edge of the diameter. Because the beveled blade's cutting angle naturally creates a sequence of "one side cutting in first, one side cutting out first," the force curve exhibits a pattern of "low initial force → slow increase → slow decrease to 0," without any sudden impact changes.

[0075] Comparison of initial entry, cutting effect position, and force curve changes in double straight blade cutting and double oblique blade cutting. Figure 9 As shown.

[0076] 2) In scenarios with multiple fruit stems, the cutting force of an angled blade gradually increases, while that of a straight blade increases dramatically.

[0077] The cutting surface of a straight blade is the "continuous full width" of the gap. If multiple fruit stems are in the cutting area at the same time, it will instantly form a total cutting effect of "N times the diameter of the fruit stem" (N is the number of fruit stems being cut at the same time). The force will directly increase by N times, which can easily exceed the engineering redundancy margin of the motor (for example, if the design redundancy is based on 2 fruit stems, it will be overloaded if there are 3 in reality).

[0078] The cutting surface of the beveled blade is a "segmented oblique contact," especially with a structure containing beveled teeth. Multiple fruit stalks are naturally distributed between different beveled teeth, with varying distances between them. The cutting start time and peak force occurrence time of each fruit stalk are different (the timing difference of progressive cutting). Especially among multiple fruit stalks between a single tooth, a shearing effect can be achieved one by one. The force superposition is a "gradual accumulation" rather than a "step doubling." Even with three fruit stalks, the total peak force is simply the sequential superposition of the peak forces of the three fruit stalks (rather than simultaneous superposition), resulting in a smoother load curve that is easier for the motor to handle.

[0079] 3) Cutting mode: the beveled edge is for "cutting + slicing", while the straight edge is for pure cutting.

[0080] The angled edge of the blade generates two components of force: a shearing force, perpendicular to the blade, which directly cuts the fruit stalk fibers; and a lateral force, parallel to the blade, which pushes the fruit stalk to one side, creating a "cutting" effect. The combined effect of these two forces allows the angled blade to not only "shear" but also "tear" the fruit stalk's epidermis and fibers (similar to the tearing effect of scissors cutting fabric at an angle), making it easier to "break through the cell walls," and the shearing force is much smaller than the "pure shearing" force of a straight blade.

[0081] The straight blade overcomes the shear strength of the fruit stalk fibers solely through "shearing force," resulting in a naturally greater shearing force.

[0082] 4) Comparison of work done: The integral result of oblique cutting ("low force, long stroke") is smaller than that of straight cutting ("high force, short stroke").

[0083] Based on the above force analysis, oblique cutting exhibits a "low force - long stroke" characteristic, while straight-edge cutting exhibits a "high force - short stroke" characteristic. Integrating the force-displacement curve (i.e., calculating the area under the curve) reveals that although the theoretical stroke S' of oblique cutting is slightly longer, its peak force and average cutting force are far lower than those of straight-edge cutting, resulting in significantly less total work done (i.e., less mechanical energy consumed). This is the core energy efficiency advantage of oblique cutting, and its energy-saving and consumption-reducing effects are particularly prominent in agricultural automation scenarios requiring long-term, large-scale operations.

[0084] For standardized comparison, an ideal model of two-bladed symmetrical relative motion shearing is used. As a simplified model, the stroke of a two-bladed symmetrical cut is approximately half the stroke of a single-bladed cut on one side of the fruit stalk, comparing straight and oblique blades. The stroke of the straight blade is... The stroke of the diagonal blade is This model reveals the fundamental relationship between stroke, diameter D, and cutting angle θ, as detailed in [link to relevant documentation]. Figure 10 In the picture, These represent the blade movement distances for beveled single-blade cutting, beveled double-blade cutting, straight single-blade cutting, and straight double-blade cutting, respectively. The definitions of each graphic in the diagram are... Figure 9 The definitions are the same.

[0085] However, during actual shearing, the stem material deforms and separates. Based on a more precise analysis of the shearing physics, this invention recognizes that the effective cutting path of the cutting edge is longer, as shown in the comparison of Figure 9(a) and (b), and the two figures at the bottom of Figure 10. The actual effective stroke of a single-sided cutting edge from the initial contact point to the completion of the coordinated cut is shown. A more accurate description would be:

[0086]

[0087] In this formula, the first term Consistent with the ideal simplified model, it represents the basic geometric motion components; the second term This reflects the additional stroke component required to achieve final material separation during the double-bevel 'clamping' process. For a small bevel inclination angle of 10°, the data in the first item... Approximately the same as the straight cut The itineraries are very close, while the second data is approximately The overall oblique cutting stroke is only about 19% longer than the straight cutting stroke.

[0088] It is worth noting that, although the precise formula model shows the actual effective travel... Slightly larger than the ideal simplified value and straight blade cutting stroke However, this precisely reflects the core advantage of the oblique-edge double-edged shear: "exchanging a longer but gentler path for lower shear force." As shown in the force curve, due to the sliding effect of the oblique edge and the progressive separation characteristic of the double edge, its cutting force is reduced throughout the entire increasing stroke. The internal levels remain low, resulting in a total power consumption (area of ​​integral of force-displacement curve) that is still much smaller than that of parallel blade cutting.

[0089] The above formula is a quantitative description based on the actual cutting physical process. Its core purpose is to reflect the difference in stroke between the double-edged oblique cutting and the straight cutting. Its precise value may fluctuate to some extent depending on the fruit stem material, cutting edge angle, etc., but it does not affect the core conclusion of 'small stroke difference and significant force advantage'. Regarding the matching of stroke and tooth spacing, even with additional stroke, the maximum stroke of the double-edged oblique cutting (calculated with D=5mm, θ=10°, S'2≈2.98mm) is still much smaller than the tooth spacing (8mm), which will not cause the fruit stem to get stuck or the cutting to be discontinuous.

[0090] Therefore, the slight increase in stroke is not a disadvantage, but rather a necessary and efficient design for achieving smooth, low-damage, and low-power shearing. This further proves that the energy-saving advantage of oblique blade shearing does not come from stroke variation, but fundamentally stems from its reduction of cutting force through the sliding effect.

[0091] Example 2: For use in automated harvesting systems

[0092] like Figure 11 As shown, based on the above embodiment, this embodiment mounts the shearing harvesting device to the end of a six-degree-of-freedom robotic arm via a flange. A vision module (camera) is installed on the wrist of the robotic arm or near the device. The vision module captures images of the working area in front, identifies cherry fruits, and locates the spatial coordinates of the end of the fruit stem using image processing algorithms.

[0093] The robotic arm control system receives coordinate information and plans the harvesting path.

[0094] The shearing action control logic is as follows: Figure 12 As shown, two main fruit distribution patterns are considered:

[0095] One type is for a single or cluster of fruits, where the relative position of the fruit to the branch can be clearly distinguished. A single-stroke insertion and cutting control mode is used, that is, a single fruit that is easy to separate and easy to distinguish from other fruits and branches is directly inserted between the fruit and the branch in one stroke through this device. The insertion depth exceeds the position of the fruit stalk. Through the continuous cutting of the teeth, the fruit is cut off and falls into the open fruit receiving device below.

[0096] Another scenario involves multiple fruits or clusters of fruits growing together, with varying orientations. Direct cutting cannot achieve a precise cut location or may cause interference, making it difficult to distinguish between individual fruits or clusters. In this case, a sweeping-cutting mode can be used. The device is positioned close to the branch, even with its upper surface directly against the branch. The length of the cutting teeth intersects the branch's growth direction. The device moves slowly along the branch's growth direction, continuously cutting through the teeth, removing all fruits along the sweeping path and on the side of the branch it is touching. The device's orientation and position are then adjusted. If fruits are found on the other side of the branch, the cutting teeth are moved to the other side, and the sweeping-cutting process is repeated. For all of these cutting processes, an open-top fruit-collecting container that moves with the device can be placed below it, enabling rapid harvesting throughout the entire process.

[0097] Specific strategies can be based on the above two strategies, with appropriate adjustments to the orientation, tilt angle, and distance from the fruit tree branches (vertical distance between the toothed row and the branch) to adapt to complex on-site scenarios, but the basic logic should conform to the above logic. For locations where it is difficult to cut, such as where fruits are clustered at the end of branches or where multiple fruits are distributed, it is even possible to directly cut off the entire small branch at the end, cutting off the fruit along with the small branch. This is a common harvesting method for fruit farmers, especially suitable for dense fruit clusters.

[0098] In this process, the cutting device does not need to be precisely aligned with the fruit stem. It only needs to ensure that the stem falls within the width of the toothed row along its length. Because the teeth are closely spaced, the cutting can be completed as long as the stem falls between any tooth. This greatly reduces the requirements for control precision, which in turn reduces the positioning and recognition accuracy of the robotic arm and the difficulty of high-position alignment when the operator holds the device.

[0099] Cutting a single fruit or a cluster of fruits:

[0100] Taking vertically downward-distributed fruits as an example, such as Figure 13 As shown. For automated and semi-automated applications such as robotic arms, after installing this shearing structure at the end of the robotic arm, the distribution position of the fruit and its relative branches is first obtained through video images. This is already a relatively mature technology and is not the subject of this patent application; it is only used as an input parameter and a reference for setting the target coordinates. Based on the positional coordinate relationship of the fruit 10, the stem 11, and the branch 12, the robotic arm controls the toothed rack to adjust its posture, with the entire length of the toothed rack facing the fruit. The upper surface of the moving toothed rack is preferably about 1 cm lower than the branch. The servo control board controls the servo to continuously drive the toothed rack to cut. At the same time, the robotic arm drives the toothed rack to move closer to the fruit, setting its final stop position to exceed the coordinate position of the preceding fruit. During this cutting stroke, the fruit stem naturally enters the space between the teeth along the fixed tooth guide, and is then sheared by the moving teeth within 1-2 seconds.

[0101] Branches clustered together, fruit swept and cut:

[0102] by Figure 14 Taking the fruit shown as an example. For automated and semi-automated applications such as robotic arms, after installing the shearing structure at the end of the robotic arm, the distribution position of the fruit and its relative to the branch is first obtained through video images. This is already a relatively mature technology and is not the subject of this invention; it is only used as an input parameter as a reference for setting the target coordinates. Based on the position coordinate relationship between the fruit and the branch, for scenarios where multiple clusters are densely distributed on the branch, the robotic arm controls the toothed rack to adjust its posture. First, the entire length of the toothed rack is inserted into the bottom of the branch, with the tooth tips facing the fruit. The upper surface of the moving toothed rack is preferably close to or even directly in contact with the surface. The servo control board controls the servo to continuously drive the toothed rack to cut. At the same time, the robotic arm drives the toothed rack to continuously move along the growth direction of the branch, sweeping over all the fruits distributed on the branches. Precise positioning is not required; its final stop position is set to exceed the final desired fruit cut by a certain distance, which can be flexibly set. During this cutting stroke, the fruit stalk naturally enters the space between the teeth along the fixed tooth guide, and is then sheared by the moving teeth within 1-2 seconds.

[0103] Example 3: Handheld Harvesting Pole

[0104] Currently, servo motors can be selected from reciprocating oscillation motors with mechanical limits for 0-180° swing angles, or servo motors without limits that can continuously rotate 0-360°, or high-torque geared motors. For the 0-180° swing angle range, the corresponding movement range of the moving gear rack is ±D / 2 (D is the diameter of the eccentric wheel's eccentric position). Common PWM servo motors send PWM square waves via a circuit board, using their pulse width range to control the rotation angle; for example, a pulse width of 500-2500µs corresponds to a 0-180° rotation angle. In this patent, the controller is configured to cyclically output PWM signals with a first pulse width (e.g., 500µs) and a second pulse width (e.g., 2500µs) to drive the motor in reciprocating oscillations. There is a preset interval (e.g., 1-2 seconds) between adjacent signals, thus enabling the eccentric wheel to drive the moving gear rack to cyclically cut the fruit stalks between the teeth within 1-2 seconds, within the 0-D range.

[0105] The total thickness of the two toothed rows in this invention is controlled within 10mm, which can ensure that most of the cherry fruit falls outside the tooth thickness and only the fruit stem is cut off; it can also take into account the relatively short fruit stems of young fruits such as apples, which are 1-2cm shorter.

[0106] A handheld pole 13 is mounted on the back of the motor mounting frame of the shearing harvester. A battery is fitted at a suitable position at the end of the handheld pole 13, and a net bag 16 is fixed to the handheld pole 13. Figure 15 As shown, it can realize semi-automatic cutting and grafting operations for high-positioned fruits through in-situ manual operation.

[0107] Furthermore, based on the current embodiment, a camera 14 is added to the top of the handheld pole 13, and an LCD screen 15 is added near the grip area. An external portable battery is also provided (which may be built into the handheld pole or placed on the back of the LCD screen). The camera displays a partial image of the top of the pole on the LCD screen to address the difficulty of aligning the fruit stem when operating on distant branches. This addition primarily considers that when the operator has poor eyesight or an obstructed field of vision, they can observe and operate the cutting through the LCD screen. After cutting, the fruit falls into the nearby receiving net. After the device catches a portion of the fruit, the handheld pole is lowered, and the operation continues after unloading the fruit. The external portable battery can be an external backpack battery (different capacity batteries are optional), which reduces the weight of handheld operation and allows for direct replacement of the battery when it runs out (recharging the original battery) to maintain continuous operation.

[0108] In addition, considering the flexibility of adjusting the orientation of the shearing device, a rotary motor can be added between the device and the handheld handle. The motor shaft is fixedly connected to the shearing device, and the opposite bottom surface of the motor shaft is fixed using the current structure connected to the connecting rod. A three-position button for forward and reverse orientation control is added near the handheld part. The rotary motor is electrically connected to the control circuit of the handheld part. The three-position button is used to send forward, stop, or reverse commands to the control circuit to adjust the orientation of the shearing device. In this way, the orientation of the shearing device can be adjusted to suit the shearing centering requirements of fruits with different growth postures and positions.

[0109] like Figure 16 As shown, a short hand handle 17 is installed on the back of the motor mounting frame of the shearing and harvesting device. The handle has a built-in battery. When working, the power is turned on by switching on the hand handle 17, which drives the servo motor to drive the gear rack to work continuously for shearing. This can help fruit farmers quickly cut and pick the fruit on the pruned branches after pruning: that is, by holding the handle, the fruit on the pruned branches is swept and cut off quickly, avoiding the workload of manual picking and improving work efficiency.

[0110] Example 4: Modified tooth shape for pruning coarse branches

[0111] To balance tooth strength and shearing force, the tooth shape in this patent, besides having a triangular cross-section, can also be modified to a trapezoidal cross-section. The tooth cutting edge has a roughly equal thickness from root to tip, or a relatively gentle decrease in thickness, enhancing its strength and making it more suitable for scenarios involving shearing smaller branches or other materials with relatively larger diameters and greater cutting forces. Its tooth shape is as follows: Figure 17 and Figure 18 As shown, Figure 17 It has a mixed tooth shape with trapezoidal and triangular cross-sections. Figure 18The tooth has a trapezoidal cross-section with equal thickness. The angle between the side and the bottom of the trapezoidal cross-section is approximately 72°. This tooth has a steeper cutting edge and higher body strength, allowing it to withstand greater shearing forces.

[0112] Example 5: Extremely Lightweight Design

[0113] For applications where extreme weight reduction is considered, since the double-edged moving teeth are sufficient to cut the fruit stem, the bottom fixed teeth can be designed with lightweight, high-strength non-metallic, non-shearing teeth. For example, using reinforced nylon as the bottom teeth is easy to process, requires no complex tooth structure, and can be achieved through simple stamping, cutting, or injection molding. Figure 19 As shown, its tooth profile is exactly the same as the bottom surface of the moving tooth row, but the thickness from the tooth root to the tooth tip is the same, and there is no tooth edge (cutting edge). The tooth profile only plays a guiding role, and the shearing is basically completed by the moving tooth row alone.

[0114] To further limit the movement of the fruit stalk, the fixed tooth row can be designed with a micro-serrated shape on both sides along the direction from the tooth root to the tooth tip. This structure can prevent the fruit stalk from sliding along the tooth edge during cutting.

[0115] Example 6: Tooth count adjustment

[0116] In Example 1, there are 10 teeth, the tooth spacing is 8mm, and the total length of the tooth row is 80mm. It can be adapted to the fruit stalks of cherries, dates, etc., and even some thin branches. Fruit stalks with a diameter of 1-5mm can be cut.

[0117] The number of teeth can be further changed. For example, with 8 teeth and a tooth spacing of 10mm, the total length of the tooth row can still be maintained at 80mm, but the tooth roots can be wider, which can bear greater force and can be adapted to thicker fruit stalks with a diameter of 3-6mm or thin branches. Increasing the number of teeth to 12 with a tooth spacing of 6.7mm can still maintain the total length of the tooth row at approximately 80mm, which can be adapted to densely clustered fruits (such as small cherries and goji berries) and fruit stalks that are thinner, such as 1-2mm or even thinner. The smaller tooth spacing and reduced stroke can improve the sweeping and cutting efficiency.

[0118] Depending on actual needs, the total length and number of teeth of the tooth rack can be finely adjusted according to the application site conditions, such as making it easy to create longer or shorter tooth racks.

[0119] Example 7: Gear clearance adjustment

[0120] For fruit stalks of different diameters, the gap between the teeth can be easily adjusted by adjusting the corresponding thickness of the drag-reducing plate and the guide plate to meet the shearing requirements of fruit stalks with different fiber toughness and bonding strength.

[0121] For a fruit stalk with a diameter of 1mm, the clearance between the moving and fixed toothed racks is designed to be 5%~10% of the stalk diameter. Taking a 10% clearance as an example, the depth of the drag-reducing plate mounting groove is set to 1mm, and the thickness of the drag-reducing plate is designed to be 1.1mm. After the drag-reducing plate is pressed into the mounting groove with an interference fit, a small amount of adhesive is applied to both ends along the length direction to fix it and prevent it from slipping out with the reciprocating frictional movement of the moving toothed rack. The height of the guide plate matches the depth of the guide groove and the thickness reduction dimension of the moving toothed rack to ensure the parallelism of the movement of the moving and fixed toothed racks. When the drag-reducing plate is worn and needs to be replaced, first disassemble the connecting parts between the elastic pressure plate and the drive mechanism, then remove the moving toothed rack upwards, clean the adhesive at both ends of the drag-reducing plate, and then directly replace it with a new drag-reducing plate. The operation is convenient and does not require modification of other structures. The assembly effect of the tooth gap is as follows: Figure 20 As shown.

[0122] For fruit stalks with a diameter of 2mm, the tooth gap is still designed according to 10% of the fruit stalk diameter. Only the drag-reducing plate with a thickness of 1.2mm needs to be replaced, and a guide plate of corresponding height needs to be matched to complete the dynamic adjustment of the gap. The entire adjustment process does not require changes to the main structure. It has the characteristics of low cost, high flexibility and adaptability, and can meet the shearing adaptation needs of fruit stalks with different fiber strengths.

[0123] Meanwhile, to prevent the moving toothed rack from vertically shifting or falling off during operation, the elastic pressure plate can selectively contact different areas on the upper surface of the moving toothed rack (such as near the tooth root area or near the bottom area) according to the actual force requirements of the moving toothed rack, so as to achieve compression and constraint on different positions of the moving toothed rack, effectively avoiding the problem of the moving toothed rack lifting or falling off during shearing operations and posture changes (such as vertical, inclined, inverted, etc.).

[0124] After replacing the drag-reducing plates with different thicknesses, the preload of the elastic pressure plate can be finely adjusted by adjusting the vertical fastening screws at the base of the elastic pressure plate. The specific steps are as follows: First, loosen the horizontal fastening screws installed in the vertical groove to allow the elastic pressure plate some vertical movement. Utilizing the elastic recovery tendency of the pressure plate itself, tighten or loosen the vertical fastening screws to drive the pressure plate to achieve slight vertical displacement, thereby adjusting the pressure of the pressure plate on the moving tooth row. Preferably, a preload scale marking can be engraved on the vertical surface of the elastic pressure plate. This scale corresponds one-to-one with the pre-calibrated pressure value. When the end of the horizontal fastening screw corresponds to different scale positions, the preload can be accurately preset. After the preload is adjusted to the correct position, tighten the horizontal fastening screws to fix the preload. Furthermore, even with the preload locked, the downward pressure of the pressure plate can still be finely adjusted by slightly tightening the vertical fastening screws, using the small lever arm of the screws and the pressure plate, to adapt to different gap parameters and varying fruit stem shear forces.

[0125] The above-described gap adjustment and compression constraint scheme is applicable to all tooth spacings and arbitrary tooth row specifications described in this invention.

[0126] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A harvesting device for clustered fruits, characterized in that, Includes the mounting body, fixed gear rack, moving gear rack, drive mechanism, transmission assembly, guide assembly, drag reduction assembly, and anti-slip assembly: The mounting body has a support arm; A fixed toothed rack is fixedly connected to the support arm of the mounting body; The movable tooth row slides with the fixed tooth row through a guide component. Both the movable tooth row and the fixed tooth row have a multi-tooth densely distributed structure, with a wide root and narrow tip of each tooth. The cross-section is preferably triangular, but can also be triangular or trapezoidal. The tooth cutting edge is double-sided and double-edged. A drive mechanism is mounted on the mounting body and drives the movable gear row to perform reciprocating shearing motion relative to the fixed gear row through a transmission component. A guiding assembly includes a guide plate disposed on the movable toothed row and a guide groove disposed on the fixed toothed row. A guiding structure is provided on one side of the guide plate, and the guiding structure cooperates with the guide groove for guidance. A drag-reducing component is embedded in the mounting groove of the fixed toothed rack, so that a preset gap is formed between the moving toothed rack and the fixed toothed rack. The preset gap can be adjusted by replacing drag-reducing components of different thicknesses. An anti-movement component is disposed between the mounting body and the fixed toothed row to press the movable toothed row to prevent it from moving vertically and falling off.

2. The clustered fruit cutting and harvesting device according to claim 1, characterized in that, The transmission assembly includes an eccentric wheel and a connecting rod. The drive mechanism is a torque servo motor. The eccentric wheel is mounted on the servo motor's shaft. The two ends of the connecting rod are respectively hinged to the eccentric wheel and the moving gear rack.

3. The clustered fruit cutting and harvesting device according to claim 1, characterized in that, The guide component is a guide plate, which is made of self-lubricating non-metallic material or metal material with a self-lubricating coating on the surface, and is detachably connected to the moving gear row by screws; the guide groove is a U-shaped groove with a semi-cylindrical bottom and its radius is slightly larger than the semi-cylindrical diameter of the guide structure.

4. The clustered fruit cutting and harvesting device according to claim 1, characterized in that, The drag reduction component uses a drag reduction plate, which is interference-fitted into the mounting groove of the fixed tooth row. Both ends of the plate are fixed, and the height of the drag reduction plate is higher than the height of the mounting groove.

5. The clustered fruit cutting and harvesting device according to claim 1, characterized in that, The anti-slip component is an elastic pressure plate, which has an L-shaped structure and there are no fewer than two of them. The lateral extension of the elastic pressure plate is inclined downward at an angle of 10° to 20° with the horizontal plane, and its end edge is rounded. The vertical side of the elastic pressure plate is provided with a long groove and is fixed to the mounting body by a vertical connector and a horizontal connector. The clamping force can be finely adjusted by adjusting the height of the vertical connector.

6. The clustered fruit cutting and harvesting device according to claim 1, characterized in that, The moving toothed rack and the fixed toothed rack are made of high carbon steel, and the bottom plane of their tooth edges is coated with a PTFE self-lubricating coating; the elastic pressure plate is made of spring steel; the mounting body, the guide plate and the drag-reducing plate are made of glass fiber reinforced nylon.

7. The clustered fruit cutting and harvesting device according to claim 1, characterized in that, The toothed surfaces of the moving toothed row are provided with anti-slip grooves or micro-tooth structures.

8. A harvesting device for clustered fruits according to any one of claims 1 to 7, characterized in that, The support arm of the mounting body is provided with a reinforcing rib at the bottom, and a mounting frame for mounting the drive mechanism is provided at its end; the outer wall of the mounting frame is provided with a connection structure for connecting a handheld rod, a grip handle or a mechanical arm end mounting interface.

9. A clustered fruit cutting and harvesting device according to claim 8, characterized in that, It also includes a handheld extension rod, an image acquisition device, a display device, and a rotating mechanism. The rotating mechanism is located between the mounting frame and the end of the handheld rod or robotic arm, and is used to drive the shearing and harvesting device to rotate around its axis to adjust the shearing orientation.

10. A clustered fruit cutting and harvesting device according to claim 8, characterized in that, The handheld extension rod is connected to the back of the mounting frame, the camera is mounted on the top of the handheld extension rod, and the display screen is mounted near the gripping part of the handheld extension rod to display the images captured by the camera.

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