Self-locking rotary-picking integrated mechanical claw

Abstract

The utility model discloses a self -locking type rotates and draws integral mechanical claw belongs to agricultural automation technical field relates to the fruit and vegetable picking robot end effector, aims at solving the problem that the traditional mechanical claw fruit stalk twist break angle is limited, and the strong tenacity fruit stalk can appear twist not broken. Its core structure includes casing, motor, open and close control board, ratchet wheel and pawl mechanism, one -way transmission groove and clamping jaw assembly. Through " rotation control convex - one -way transmission groove - ratchet wheel and pawl " cooperation design, motor clockwise rotation only drives clamping jaw open and close, anticlockwise rotation realizes clamping jaw continuous rotation and twists the fruit stalk, breaks through angle limit. The multiple symmetrical arc open and close grooves ensure that the clamping jaw opens and closes synchronously, the installation ring and the ratchet wheel integrated design improve the transmission accuracy, and the heat dissipation cavity and the heat dissipation hole cooperate to guarantee the motor heat dissipation. It is applicable to different size fruit and vegetable picking, especially improves the picking efficiency and stability of the unripe high tenacity fruit stalk fruit and vegetable.

Description

Technical Field

[0001] This utility model belongs to the field of agricultural automation technology, specifically relating to an end effector for a fruit and vegetable harvesting robot, and more particularly to a rotary-harvesting integrated mechanical claw structure with continuous rotation and torsion breaking function. Background Technology

[0002] In the field of agricultural automation, the mechanical gripper of a fruit and vegetable harvesting robot is the core component for achieving efficient harvesting, and it needs to meet the dual requirements of "stable gripping and precise separation". In existing technologies, fruit and vegetable harvesting actuators mainly achieve fruit stem separation in two ways: one is by relying on shearing force (such as blade cutting), but this requires frequent blade replacement and has high maintenance costs; the other is by using rotational torque in conjunction with the pulling force of the robotic arm (this is the applicant's prior design), but its structural design has inherent defects that restrict harvesting efficiency.

[0003] The closest existing technology is the applicant's prior design, which relies on a multi-stage transmission structure (such as gear trains and linkage mechanisms) to collaboratively drive the gripper to complete complex actions such as grasping and twisting. This type of solution achieves the timing coordination of actions through a pre-set mechanical linkage path, functionally meeting the requirements for gripping and separating fruit stems. Its core value lies in effectively improving harvesting efficiency and eliminating the hassle of frequent blade replacements. Its drawback is that the twisting angle after grasping the fruit is structurally limited. This design can meet basic needs in harvesting fruits and vegetables with low stem toughness (such as strawberries and peaches) and can also meet the needs of harvesting ripe apples.

[0004] When an apple is fully ripe, the stem is relatively fragile. As the fruit matures, the cell walls in the stem gradually soften, the fiber structure degrades, the water content changes, and the mechanical strength decreases, making the stem easier to break. The applicant's previous designs could meet the harvesting requirements.

[0005] To extend shelf life (e.g., to cope with long-distance transportation), orchards sometimes need to harvest apples that are not fully ripe. Apples are respiratory fruits (aerial fruits), meaning they retain some metabolic activity after harvesting, continuing respiration and physiological changes. Unripe apples contain more starch and acid. During transportation and storage, the starch gradually converts into sugar, the acidity decreases, the fruit softens, and its color changes, gradually ripening. During this ripening process, apples are less prone to spoilage, which is why they can be harvested earlier.

[0006] The stems of unripe apples are quite tough, with strong cell walls, dense fiber tissue, high water content, and high mechanical strength. Therefore, if the existing design is still used, there is a certain probability that they will not break, requiring special treatment, which will reduce harvesting efficiency.

[0007] III. The Necessity of Improvement

[0008] To address the aforementioned shortcomings, there is an urgent need to develop a novel integrated rotary gripper, achieving the following objectives through structural innovation:

[0009] Overcoming the limitations of rotation angle: The design of a continuously rotating transmission mechanism ensures that fruits and vegetables with strong stems can be effectively twisted off.

[0010] Improve gripping stability: Optimize the gripper guide structure to achieve synchronous and uniform opening and closing of multiple grippers;

[0011] Simplified structure and improved efficiency: Reduce the number of parts, eliminate assembly gaps, and improve transmission accuracy and service life.

[0012] This utility model is proposed to solve the above problems. Through the coordinated design of "rotation control protrusion - one-way transmission groove - ratchet and pawl", multiple arc-shaped opening and closing groove guides and integrated components, it realizes the integrated and efficient action of "grabbing - rotating - twisting off", which meets the harvesting needs of various fruits and vegetables. Utility Model Content

[0013] The purpose of this invention is to provide a self-locking rotary picking integrated mechanical claw that, while inheriting the fruit stem and fruit separation technology that combines rotary torque and tensile force, breaks through the limitation of rotation angle and avoids the phenomenon of fruit stems not breaking and requiring special handling when picking fruits and vegetables with tough stems.

[0014] To achieve the above objectives, this utility model provides a self-locking rotary mechanical gripper with an unrestricted twisting angle, comprising a housing with an open top; a motor is installed inside the housing, and the motor has a motor shaft.

[0015] The housing and the motor shaft are coaxial, and this axis is a vertical straight line. This axis is defined as the axis of this utility model, and the radial direction of this axis is defined as radial.

[0016] The motor shaft extends upwards; it also includes the following structure:

[0017] The motor bracket plate is fixedly connected to the housing in the circumferential direction and fixedly connected to the motor downwards, with the motor shaft extending out through the center hole;

[0018] The opening and closing control board is fixedly connected to the top of the motor shaft and rotates as a whole with the motor shaft;

[0019] An arc-shaped opening and closing groove is provided on the opening and closing control plate, which is open at the top and bottom, with one end adjacent to the axis and the other end adjacent to the circumferential edge of the opening and closing control plate;

[0020] The positioning bearing has its outer ring fixedly connected to the housing, and its inner ring connected to the mounting ring.

[0021] The mounting ring has a ratchet on its lower surface, and the ratchet teeth engage with the pawl; the pawl is connected to the motor bracket plate via a spring shaft, so that the ratchet can only rotate continuously counterclockwise;

[0022] The inner surface of the mounting ring is provided with a radial arc-shaped rotation control protrusion, which together with the rotation control wheel and the rotation control plate forms a one-way transmission groove; the rotation control wheel is fixed to the motor shaft, and the rotation control plate is radially fixed to the outer circumference of the rotation control wheel and extends into the one-way transmission groove;

[0023] The connecting rod has a mounting ring at the lower end and a fixing plate at the upper end.

[0024] Fixed plate, connected to the slide groove upwards;

[0025] A groove extends radially, and a slide rail passes through the groove and slides radially in a sliding engagement with the groove.

[0026] The connecting seat is fixed to the slide rail at the bottom and connected to the clamps at the top;

[0027] The sliding pin passes vertically through the arc-shaped opening and closing groove, with its lower end connected to the radial inner end of the connecting seat and its upper end connected to the clamp.

[0028] The arc-shaped opening and closing grooves are arranged symmetrically with the axis as the center, with three or more grooves.

[0029] The mounting ring is integrally formed with the ratchet, and the radial outer end of the ratchet tooth is flush with the circumferential outer surface of the mounting ring.

[0030] Two rotation control protrusions are symmetrically arranged around the axis, and the unidirectional transmission grooves correspond one-to-one with the rotation control plate.

[0031] The lower end of the sliding pin is connected to the connecting seat, and the upper end is connected to the clamp. The top of the radially outer end of the connecting seat is higher than the opening and closing control plate.

[0032] The diameter of the central hole of the motor bracket plate is larger than the outer diameter of the motor shaft. The motor and the housing below it form a heat dissipation cavity, and the bottom wall of the housing is provided with heat dissipation holes.

[0033] The connecting rod is made of round copper pillars, with four pillars evenly distributed around the circumference. The lower end is connected to the mounting ring, and the upper end is connected to the fixing plate.

[0034] The groove opening faces upwards, the lower middle part of the slide rail slides through the groove, and the upper part is fixed to the connecting seat.

[0035] The bottom of the gripper is a horizontal connecting part, which is fixedly connected to the connecting seat and the sliding pin, and the multiple grippers are symmetrically distributed in the center.

[0036] The outer ring of the positioning bearing is fixed to the housing, and the inner ring is fixed to the mounting ring, allowing the mounting ring to rotate relative to the housing.

[0037] This utility model has the following advantages:

[0038] This utility model uses a collaborative structure of "rotation control protrusion 14 - one-way transmission groove 15 - ratchet and pawl". When the motor shaft rotates clockwise, only the opening and closing control plate 5 rotates (the pawl opens). When it rotates counterclockwise (the pawl closes), it drives the opening and closing mechanism to rotate continuously (without angle limitation, until the fruit stalk is twisted off), which solves the problem of incomplete fruit stalk twisting off in traditional mechanical claws.

[0039] Multiple symmetrical arc grooves ensure that the sliding pin 23 drives the gripper 24 to open and close synchronously, so that the force is balanced when gripping round fruits and vegetables, thus improving stability; the "three or more grooves" limit meets the gripping needs of fruits and vegetables of different sizes.

[0040] The integrated structure of mounting ring 8 and ratchet 9 reduces assembly clearance and improves transmission accuracy; the design of ratchet 10 flush with mounting ring 8 avoids interference with the inner wall of housing 1 and ensures smooth rotation.

[0041] The symmetrical layout balances the forces on the rotary control plate 17, preventing wear on one side; the two unidirectional transmission slots 15 ensure that torque transmission is smooth when the motor shaft rotates.

[0042] The sliding pin 23 serves both radial guidance and torque transmission functions, simplifying the structure; the height design of the connecting seat 22 avoids interference with the opening and closing control plate 5, ensuring smooth movement of the gripper 24.

[0043] The heat dissipation cavity and heat dissipation hole 2 work together to promote heat dissipation of motor 3 and avoid overheating during long-term operation; the motor bracket plate 4 improves the heat dissipation efficiency by making motor 3 suspended.

[0044] The round copper column combines rigidity and lightweight design, and the four evenly distributed connecting rods 18 ensure that the fixed plate 19 is subjected to uniform force, thus improving transmission stability.

[0045] The radial sliding engagement between the slide groove 20 and the slide rail 21 restricts the gripper 24 to move only radially, thus preventing offset during the opening and closing process.

[0046] The horizontal connecting part ensures that the gripper 24 is rigidly connected to the connecting seat 22, and the central symmetrical distribution makes the gripping force uniform, which is suitable for round fruits and vegetables.

[0047] The positioning bearing 7 provides stable rotational support for the mounting ring 8, preventing radial wobble and improving the motion accuracy of the opening and closing mechanism.

[0048] The dimensions of this utility model can be designed to match the size of the target fruits and vegetables, mainly the size of the grippers and their travel length. Attached Figure Description

[0049] Figure 1 This is a schematic diagram of the structure of this utility model.

[0050] Figure 2 yes Figure 1AA sectional view.

[0051] Figure 3 yes Figure 1 BB cross-sectional view.

[0052] Figure 4 yes Figure 1 CC section view.

[0053] The plane containing the CC section is higher than the rotating control wheel 16 and the mounting ring 8, therefore Figure 4 The rotating control wheel 16 should not ideally have a cross-sectional line, but to clearly show the boundary between the rotating control wheel 16 and the mounting ring 8 and the rotating control protrusion 14 (the latter two being integrally formed), a cross-sectional line is shown in the image. Figure 4 A cross-sectional line was drawn for the area where the rotating control wheel 16 is located.

[0054] Figure 5 yes Figure 1 DD sectional view.

[0055] Figure 6 yes Figure 1 EE sectional view.

[0056] Figure 7 This is a three-dimensional structural diagram of the present invention, viewed from above.

[0057] Figure 8 This is a three-dimensional structural diagram of the present invention, viewed from below.

[0058] Figure 9 This is a three-dimensional structural diagram of the present invention after removing the opening and closing control plate 5 and the housing 1. The related structure of the sliding pin 23 can be clearly seen.

[0059] Component names and diagram markings:

[0060] 1. Shell 1

[0061] Installation location: The mechanical claw's overall external frame, with an open top.

[0062] Structural relationship: It is fixedly connected to the motor bracket plate 4 in the circumferential direction, and the inner wall is rotatably connected to the mounting ring 8 through the positioning bearing 7. The bottom wall is provided with heat dissipation holes 2.

[0063] Working principle: It provides an overall support structure and defines the spatial position of internal components.

[0064] Technical function: To protect the internal transmission mechanism from dust and impurities, and to provide an installation reference for components such as motor 3 and positioning bearing 7.

[0065] 2. Heat dissipation hole 2

[0066] Installation location: bottom wall of housing 1, evenly distributed.

[0067] Structural relationship: It runs through the bottom of the housing 1 and is connected to the heat dissipation cavity below the motor 3.

[0068] Working principle: Heat dissipation is achieved through air convection.

[0069] Technical function: To reduce the temperature of motor 3 during long-term operation and prevent overheating damage.

[0070] 3. Motor 3

[0071] Installation location: inside housing 1, with the motor shaft extending upwards.

[0072] Structural relationship: The motor is fixedly connected to the housing 1 via the motor bracket plate 4, and the motor shaft passes through the center hole of the motor bracket plate 4 and the rotation control wheel 16 in sequence, and the top end is fixed to the opening and closing control plate 5.

[0073] Working principle: It receives external control signals and outputs clockwise / counterclockwise rotation power to the opening and closing control plate 5 and the rotation control wheel 16.

[0074] Technical function: The opening and closing control board 5 drives the opening and closing action of the gripper 24, and at the same time drives the mounting ring 8 to rotate through the rotation control board 17 to achieve the fruit stem twisting and breaking function.

[0075] 4. Motor bracket plate 4

[0076] Installation location: Inside housing 1, above motor 3.

[0077] Structural relationship: The circumferential edge is fixed to the inner wall of the housing 1, the lower surface is fixed to the outer shell of the motor 3, a through hole is opened in the center for the motor shaft to pass through, and a pawl 11 is connected to one side through a spring shaft 12.

[0078] Working principle: It supports the weight of the motor and transmits the fixing force.

[0079] Technical function: To stably install the motor 3 inside the housing 1, and at the same time provide a mounting fulcrum for the pawl 11.

[0080] 5. Opening and closing control panel 5

[0081] Installation location: Top of the motor shaft, horizontally arranged.

[0082] Structural relationship: The center is fixedly connected to the motor shaft, and an arc-shaped opening and closing groove 6 is opened on the plate.

[0083] Working principle: It rotates synchronously with the motor shaft and pushes the sliding pin 23 to move radially through the arc-shaped opening and closing groove 6.

[0084] Technical function: It converts the rotational motion of motor 3 into the opening and closing action of gripper 24 to achieve grasping and releasing.

[0085] 6. Arc-shaped opening and closing groove 6

[0086] Installation location: On the opening and closing control panel 5, evenly distributed along the circumference (preferably 4).

[0087] Structural relationship: The upper and lower open arc-shaped groove has one end adjacent to the motor shaft axis and the other end extends to the circumferential edge of the control board.

[0088] Working principle: The sliding pin 23 is guided to slide radially by the contour of the groove.

[0089] Technical function: It converts the rotational motion of the opening and closing control plate 5 into the radial displacement of the sliding pin 23, driving the gripper 24 to open or close.

[0090] 7. Locating bearing 7

[0091] Installation location: Upper part of the inner wall of housing 1, above motor bracket plate 4.

[0092] Structural relationship: The outer ring is interference-fitted with the housing 1 (fixed connection), and the inner ring is interference-fitted with the mounting ring 8 (fixed connection).

[0093] Working principle: Reduce the frictional resistance when the mounting ring 8 rotates to maintain coaxiality.

[0094] Technical function: To provide stable rotational support for the mounting ring 8 and ensure the coaxiality and stability of the gripper 24 during rotation.

[0095] 8. Install ring 8

[0096] Installation location: The inner ring of the positioning bearing 7 is located on the upper part of the housing 1.

[0097] Structural relationship: The lower surface is integrally formed with the ratchet 9, the inner surface is provided with a rotation control protrusion 14, and the outer periphery is fixedly connected to the fixing plate 19 through the connecting rod 18.

[0098] Working principle: The positioning bearing 7 rotates relative to the housing 1, which drives the connecting rod 18 and the fixing plate 19 to rotate synchronously.

[0099] Technical function: To transmit rotational power to the gripper 24, enabling continuous rotational action to twist off the fruit stalk.

[0100] 9. Ratchet 9

[0101] Installation location: on the lower surface of mounting ring 8, coaxial with mounting ring 8.

[0102] Structural relationship: The outer peripheral distribution of ratchet teeth 10 engages unidirectionally with pawl 11.

[0103] Working principle: The ratchet 10 and the pawl 11 work together to restrict the clockwise rotation of the mounting ring 8, while allowing counterclockwise rotation.

[0104] Technical function: To achieve unidirectional rotation locking, ensuring that the gripper can rotate counterclockwise indefinitely during the 24-stage process of twisting off the fruit stem, thus preventing loosening in the opposite direction.

[0105] 10. Ratchets 10

[0106] Installation location: outer periphery of ratchet 9, evenly distributed along the circumference.

[0107] Structural relationship: One side of the tooth surface is a steep surface, and the other side is a gentle slope surface, which mates with the claw end of the pawl 11.

[0108] Working principle: Pawl 11 engages with ratchet 10 under the action of spring shaft 12 (and torsion spring 13), preventing ratchet 9 from rotating clockwise; when rotating counterclockwise, the gentle slope of ratchet 10 pushes pawl 11 to overcome the spring force and lift it up, achieving unidirectional overtaking.

[0109] Technical function: To form a one-way transmission mechanism to ensure that the rotation direction of the mounting ring 8 is controllable.

[0110] 11. Razor Claw

[0111] Installation location: On the upper surface of the motor bracket plate 4, below the ratchet 9.

[0112] Structural relationship: It is hinged to the motor bracket plate 4 via the spring shaft 12, and the claw end engages with the ratchet 10.

[0113] Working principle: Under the elastic force of the spring shaft 12 and its torsion spring 13, it maintains the meshing state with the ratchet 10, and can rotate around the spring shaft 12 when pushed by the ratchet 10.

[0114] Technical function: It works with ratchet 9 to achieve one-way locking and prevent the gripper 24 from rotating clockwise when it is not in operation.

[0115] 12. Spring shaft 12

[0116] Installation location: between motor bracket plate 4 and pawl 11.

[0117] Structural relationship: The shaft passes through the mounting hole of the pawl 11 and is fixed to the motor bracket plate 4 at both ends. A torsion spring 13 is sleeved on the outer periphery. One end of the torsion spring 13 abuts against the motor bracket plate 4, and the other end abuts against the pawl 11. The torsion spring 13 will not be described separately.

[0118] Working principle: The preload of the torsion spring 13 keeps the pawl 11 engaged with the ratchet 10.

[0119] Technical function: To provide a reset force for the pawl 11, ensuring the reliability of the one-way locking mechanism.

[0120] 13. Rotation control protrusion 14

[0121] Installation location: Two are symmetrically distributed circumferentially on the inner surface of mounting ring 8.

[0122] Structural relationship: The radial arc-shaped protrusion, together with the inner wall of the mounting ring 8, the rotation control wheel 16, and the rotation control plate 17, forms a one-way transmission groove 15.

[0123] Working principle: When the rotary control plate 17 rotates counterclockwise, it is pushed by the plate, which drives the mounting ring 8 to rotate synchronously.

[0124] Technical function: To transmit the rotational power of the rotary control plate 17 to the mounting ring 8, thereby realizing the overall rotation of the gripper 24.

[0125] 14. One-way transmission groove 15

[0126] Installation location: The inner ring of the mounting ring 8 is formed by the inner wall of the mounting ring 8, the rotation control protrusion 14, the outer circumference of the rotation control wheel 16, and the side of the rotation control plate 17.

[0127] Structural relationship: The arc-shaped groove has an open end at the clockwise end (allowing the rotary control plate 17 to slide without transmitting torque) and a closed end at the counterclockwise end (rigidly contacting the rotary control plate 17 to transmit torque).

[0128] Working principle: When the motor rotates clockwise, the rotation control plate 17 slides clockwise along the groove (without driving the mounting ring 8); when the motor rotates counterclockwise, the rotation control plate 17 abuts against the closed end, pushing the mounting ring 8 to rotate.

[0129] Technical function: To decouple the opening and closing action from the rotation action, and to prevent the gripper 24 from rotating erroneously during the opening / closing phase.

[0130] 15. Rotary control wheel 16

[0131] Installation location: Middle of the motor shaft, above the motor bracket plate 4.

[0132] Structural relationship: The center is fixedly connected to the motor shaft, and the outer periphery extends radially outward to form a rotary control plate 17.

[0133] Working principle: It rotates synchronously with the motor shaft, driving the rotation control plate 17 to move within the one-way transmission groove 15.

[0134] Technical function: It transmits the rotational power of motor 3 to rotation control board 17 and is an intermediate connecting component for rotation drive.

[0135] 16. Rotary control panel 17

[0136] Installation location: on the outer circumference of the rotating control wheel 16, extending radially.

[0137] Structural relationship: One end is fixed to the rotating control wheel 16, and the other end extends into the one-way transmission groove 15.

[0138] Working principle: As the rotary control wheel 16 rotates, it slides or pushes the rotary control protrusion 14 within the one-way transmission groove 15.

[0139] Technical function: Switching between "idle" and "drive" states based on the rotation direction of motor 3 to achieve on-demand output of rotational motion.

[0140] 17. Connecting rod 18

[0141] Installation location: between the mounting ring 8 and the fixing plate 19, evenly distributed along the circumference (4 rings).

[0142] Structural relationship: The lower end is fixed to the upper surface of the mounting ring 8, and the upper end is fixed to the lower surface of the fixing plate 19.

[0143] Working principle: The rotational motion of the mounting ring 8 is transmitted to the fixed plate 19.

[0144] Technical function: Connecting the mounting ring 8 and the fixing plate 19 to form a rigid transmission chain, ensuring the stable transmission of rotational torque.

[0145] 18. Fixing plate 19

[0146] Installation location: Top of connecting rod 18, horizontally arranged.

[0147] Structural relationship: The lower surface is fixed to the connecting rod 18, and the upper surface has a sliding groove 20.

[0148] Working principle: It rotates synchronously with the connecting rod 18, providing an installation base for the slide 20.

[0149] Technical function: To support the slide 20 and gripper 24, and to transmit rotational motion to the gripping mechanism.

[0150] 19. Slide 20

[0151] Installation location: upper surface of fixing plate 19, extending radially.

[0152] Structural relationship: The slot faces upward and slides with the slide rail 21, and the number corresponds to the number of grippers 24 (preferably 4).

[0153] Working principle: The slide rail 21 is restricted to sliding only radially to prevent circumferential displacement when the gripper 24 opens and closes.

[0154] Technical function: To guide the radial movement trajectory of the gripper 24 and ensure the accuracy of the gripping action.

[0155] 20. Slide rail 21

[0156] Installation location: within the slide groove 20, arranged radially.

[0157] Structural relationship: The lower part slides with the slide groove 20, and the upper part is fixedly connected to the connecting seat 22.

[0158] Working principle: Driven by the sliding pin 23, it slides radially along the slide groove 20.

[0159] Technical function: to transmit the radial displacement of the sliding pin 23 to the connecting seat 22, driving the gripper 24 to open and close.

[0160] 21. Connector 22

[0161] Installation location: Top of slide rail 21, above the mounting plate 19.

[0162] Structural relationship: The lower part is fixed to the slide rail 21, and the upper part is fixedly connected to the gripper 24 and the sliding pin 23.

[0163] Working principle: It synchronously receives the radial force of the slide rail 21 and the driving force of the sliding pin 23, which drives the gripper 24 to move.

[0164] Technical function: Connects slide rail 21, sliding pin 23 and gripper 24, integrating opening, closing and rotation actions.

[0165] 22. Sliding pin 23

[0166] Installation location: within the arc-shaped opening and closing groove 6, arranged vertically.

[0167] Structural relationship: The lower end passes through the arc-shaped opening and closing groove 6 and is fixed to the connecting seat 22, while the upper end is fixed to the clamp 24.

[0168] Working principle: As the arc-shaped opening and closing groove 6 rotates, it moves radially, driving the connecting seat 22 and the gripper 24 to move synchronously.

[0169] Technical function: It converts the rotational motion of the opening and closing control plate 5 into the radial opening and closing action of the gripper 24, and is the core transmission component of the opening and closing mechanism.

[0170] 23. Gripper 24

[0171] Installation location: Top of connector 22, symmetrically distributed along the circumferential center (4 in this embodiment).

[0172] Structural relationship: The bottom horizontal section is fixed to the connecting seat 22 and the sliding pin 23, and the upper part is an arc-shaped gripping end (the inner surface may be provided with anti-slip texture, not shown).

[0173] Working principle: The fruit is grasped by opening and closing radially, and the fruit stem is twisted off by rotating with the fixed plate 19.

[0174] Technical function: Directly contact and grasp fruits and vegetables, and break the fruit stem by rotating torque to complete the picking action. Detailed Implementation

[0175] like Figures 1 to 9 As shown, this utility model discloses a self-locking rotary gripper with an unrestricted twisting angle, comprising a housing 1 with an open top; a motor 3 is installed inside the housing 1, the motor 3 has a motor shaft, the housing 1 and the motor shaft are coaxial, and this axis is a vertical straight line (vertical is a relative direction, defined to clearly express the relative structural relationship between components, and naturally cannot remain unchanged during use as the robotic arm moves), this axis is defined as the axis of this utility model, and the radial direction of this axis is defined as radial; the clockwise and counterclockwise directions mentioned below are based on the clockwise and counterclockwise directions from the top view;

[0176] The motor shaft extends upwards; it also includes the following structure:

[0177] The motor bracket plate 4 is fixedly connected to the housing 1 in the circumferential direction and fixedly connected to the motor 3 in the downward direction. The motor shaft extends out through the center hole.

[0178] The opening and closing control board 5 is fixedly connected to the top of the motor shaft and rotates as a whole with the motor shaft;

[0179] An arc-shaped opening and closing groove 6 is provided on the opening and closing control plate 5, which is open at the top and bottom, with one end adjacent to the axis and the other end adjacent to the circumferential edge of the opening and closing control plate 5.

[0180] Positioning bearing 7, the outer ring is fixedly connected to housing 1, and the inner ring is connected to mounting ring 8;

[0181] The mounting ring 8 has a ratchet 9 on its lower surface. The ratchet teeth 10 of the ratchet 9 engage with the pawl 11. The pawl 11 is connected to the motor bracket plate 4 via a spring shaft 12, allowing the ratchet 9 to rotate continuously counterclockwise (not clockwise). When rotating clockwise, the pawl 11 will press against the ratchet teeth 10. A torsion spring 13 is mounted on the spring shaft 12, and the torsion spring 13 is connected to the pawl 11, ensuring that the pawl 11 is always pressed tightly against the outer circumferential surface of the ratchet 9.

[0182] The inner surface of the mounting ring 8 is provided with a radial arc-shaped rotation control protrusion 14, which together with the rotation control wheel 16 and the rotation control plate 17 form a one-way transmission groove 15; the rotation control wheel 16 is fixed to the motor shaft (or is connected to the motor shaft via a transmission pin), and the rotation control plate 17 is radially fixed to the outer circumference of the rotation control wheel 16 and extends into the one-way transmission groove 15; in this embodiment, the rotation control plate 17 and the rotation control wheel 16 are integrally set.

[0183] Connecting rod 18, with mounting ring 8 at the lower end and fixing plate 19 at the upper end;

[0184] The fixing plate 19 is fixed downward to the connecting rod 18 and connected upward to the sliding groove 20;

[0185] The slide groove 20 extends radially, and the slide rail 21 passes through the slide groove 20 and slides radially in contact with the slide groove 20;

[0186] The connecting seat 22 is fixed to the slide rail 21 at the bottom and connected to the gripper 24 at the top. Its radial inner end is located below the opening and closing control plate 5.

[0187] The sliding pin 23 passes vertically through the arc-shaped opening and closing groove 6, with its lower end connected to the radial inner end of the connecting seat 22 and its upper end connected to the clamp 24.

[0188] This utility model uses a collaborative structure of "rotation control protrusion 14 - one-way transmission groove 15 - ratchet and pawl". When the motor shaft rotates clockwise, only the opening and closing control plate 5 rotates (the pawl opens). When it rotates counterclockwise (the pawl closes), it drives the opening and closing mechanism to rotate continuously (without angle limitation, until the fruit stalk is twisted off), which solves the problem of incomplete fruit stalk twisting off in traditional mechanical claws.

[0189] The arc-shaped opening and closing groove 6 is symmetrically arranged in three or more rows around the axis, preferably four rows.

[0190] Multiple symmetrical arc grooves ensure that the sliding pin 23 drives the gripper 24 to open and close synchronously, so that the force is balanced when gripping round fruits and vegetables, thus improving stability; the "three or more grooves" limit meets the gripping needs of fruits and vegetables of different sizes.

[0191] The mounting ring 8 and the ratchet 9 are integrally formed, and the radial outer end of the ratchet 10 is flush with the circumferential outer surface of the mounting ring 8.

[0192] The integrated structure of mounting ring 8 and ratchet 9 reduces assembly clearance and improves transmission accuracy; the design of ratchet 10 flush with mounting ring 8 avoids interference with the inner wall of housing 1 and ensures smooth rotation.

[0193] The rotation control protrusion 14 is arranged symmetrically with the axis as the center, and the unidirectional transmission groove 15 corresponds one-to-one with the rotation control plate 17.

[0194] The symmetrical layout balances the forces on the rotary control plate 17, preventing wear on one side; the two unidirectional transmission slots 15 ensure that torque transmission is smooth when the motor shaft rotates.

[0195] The lower end of the sliding pin 23 is connected to the connecting seat 22, and the upper end is connected to the gripper 24. The top of the radially outer end of the connecting seat 22 is higher than the opening and closing control plate 5.

[0196] The sliding pin 23 serves both radial guidance and torque transmission functions, simplifying the structure; the height design of the connecting seat 22 avoids interference with the opening and closing control plate 5, ensuring smooth movement of the gripper 24.

[0197] The diameter of the central hole of the motor bracket plate 4 is larger than the outer diameter of the motor shaft. The motor 3 and the housing 1 below it form a heat dissipation cavity. The bottom wall of the housing 1 is provided with heat dissipation holes 2.

[0198] The heat dissipation cavity and heat dissipation hole 2 work together to promote heat dissipation of motor 3 and avoid overheating during long-term operation; the motor bracket plate 4 improves the heat dissipation efficiency by making motor 3 suspended.

[0199] The connecting rod 18 is a round copper column with four evenly distributed around its circumference. The lower end is connected to the mounting ring 8, and the upper end is connected to the fixing plate 19. The round copper column combines rigidity and lightweight, and the evenly distributed design of the four connecting rods 18 ensures that the fixing plate 19 is subjected to uniform force, thereby improving transmission stability.

[0200] The groove 20 has its opening facing upwards, and the lower middle part of the slide rail 21 slides through the groove 20 while the upper part is fixed to the connecting seat 22.

[0201] The radial sliding engagement between the slide groove 20 and the slide rail 21 restricts the gripper 24 to move only radially, thus preventing offset during the opening and closing process.

[0202] The bottom of the gripper 24 is a horizontal connecting part, which is fixedly connected to the connecting seat 22 and the sliding pin 23. Multiple grippers 24 are symmetrically distributed in a central direction. The horizontal connecting part ensures that the gripper 24 is rigidly connected to the connecting seat 22, and the symmetrical distribution in a central direction ensures that the gripping force is uniform, making it suitable for round fruits and vegetables.

[0203] The outer ring of the positioning bearing 7 is fixed to the housing 1, and the inner ring is fixed to the mounting ring 8, allowing the mounting ring 8 to rotate relative to the housing 1. The positioning bearing 7 provides stable rotational support for the mounting ring 8, preventing radial wobble and improving the motion accuracy of the opening and closing mechanism.

[0204] When in use, this utility model is installed on a harvesting robot and is controlled by the harvesting robot.

[0205] The detailed working process of this utility model is as follows:

[0206] I. Initial State

[0207] Structural state: The gripper 24 is in the closed state, and the pawl 11 is engaged with the ratchet 10 of the ratchet 9 under the action of the spring shaft 12, which restricts the mounting ring 8 from rotating clockwise; the rotation control plate 17 is located at the clockwise end (non-drive position) of the one-way transmission groove 15.

[0208] Technical principle: The ratchet and pawl mechanism has a one-way locking characteristic, which ensures that the pawl 24 does not rotate accidentally when not in operation.

[0209] II. Gripper opening stage (motor rotates clockwise)

[0210] Power input: Motor 3 drives the motor shaft to rotate clockwise, which in turn drives the opening and closing control board 5 to rotate clockwise synchronously.

[0211] Opening and closing action: The arc-shaped opening and closing groove 6 rotates with the opening and closing control plate 5, pushing the sliding pin 23 to move along the groove from the "adjacent axis end" to the "adjacent circumferential edge end" (sliding radially outward).

[0212] Linkage component: The sliding pin 23 drives the connecting seat 22 and the slide rail 21 to slide radially outward along the slide groove 20, which eventually makes each gripper 24 move away from the axis and realize the gripper opening action.

[0213] Rotational decoupling: The rotational control plate 17 rotates clockwise with the motor shaft and slides along the arc path of the one-way transmission groove 15 (without contacting the rotational control protrusion 14), while the mounting ring 8 does not rotate due to the ratchet pawl locking.

[0214] Technical advantages: By "sliding cooperation between the one-way transmission groove 15 and the rotation control plate 17", "decoupling of opening and closing action and rotation action" is achieved, avoiding accidental rotation of the gripper when it opens or restricting the entire mechanism from rotating, ensuring smooth operation and improving operational safety.

[0215] III. Grasping and Rotation Torsion Stage (Motor rotates counterclockwise)

[0216] Gripper closure: Motor 3 switches to counterclockwise rotation, opening and closing control board 5 drives arc-shaped opening and closing groove 6 to rotate in the opposite direction, sliding pin 23 moves radially inward along the groove, gripper 24 closes to grab fruits and vegetables.

[0217] Rotation drive: The rotation control plate 17 rotates counterclockwise with the motor shaft. Its end contacts and pushes the rotation control protrusion 14, driving the mounting ring 8 to overcome the ratchet and pawl resistance (the pawl 11 is smoothly lifted by the circumferential surface of the ratchet 10 and compresses the spring shaft 12), driving the connecting rod 18, the fixing plate 19 and the gripper 24 to rotate continuously counterclockwise (without angle limitation).

[0218] Technical principle: The rigid push of "rotation control plate 17 - rotation control protrusion 14 - one-way transmission groove 15" combined with the one-way overtaking function of ratchet and pawl realizes the continuous rotation of pawl 24.

[0219] Technical advantages: It breaks through the rotation angle limitation of the traditional single ratchet mechanism, avoids the occasional phenomenon of fruit stems not being able to be twisted (mainly when the fruit stems are too tough), and eliminates the need for manual troubleshooting when they cannot be twisted, thus improving harvesting efficiency.

[0220] IV. Reset and Release Phase

[0221] Rotation reset: After the fruit stem is twisted off, the motor 3 rotates clockwise briefly, and the gripper 24 opens again to release the fruit; the rotation control plate 17 retracts to the initial position of the one-way transmission groove 15, the pawl 11 re-engages with the ratchet 10, and the mounting ring 8 returns to locking.

[0222] Cyclic operation: Repeat the “open-grab-rotate-twist-release” process to enter the next harvesting cycle.

[0223] Technical advantages: The symmetrical design of multiple arc-shaped opening and closing grooves 6 (preferably four grooves) ensures that the gripper 24 is subjected to uniform force, effectively guaranteeing gripping stability; the integrated design of the mounting ring 8 and ratchet 9 eliminates assembly gaps, resulting in fast transmission response speed and eliminating transmission deviation and transmission failure.

[0224] This invention achieves a breakthrough in continuous rotation: the triple synergistic structure (rotation control protrusion + unidirectional transmission groove + ratchet and pawl) enables unlimited rotation, adapting to the harvesting of highly resilient fruit stalks.

[0225] This utility model has strong structural stability: multiple components are integrated into one unit (mounting ring and ratchet), symmetrical layout (arc-shaped opening and closing groove, gripper), relatively few transmission components, low failure rate, and strong stability.

[0226] This invention features highly efficient motion decoupling: clockwise rotation only opens and closes, while counterclockwise rotation is linked, avoiding motion interference and resulting in faster single-cycle operation.

[0227] The above embodiments are only used to illustrate and not limit the technical solutions of this utility model. Although the utility model has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the utility model without departing from the spirit and scope of the utility model. Any modifications or partial substitutions should be covered within the scope of the claims of this utility model.

Claims

1. A self-locking rotary mechanical gripper with an unrestricted twisting angle, comprising a housing (1) with an open top; a motor (3) is installed inside the housing (1), the motor (3) having a motor shaft, characterized in that: The housing (1) and the motor shaft are coaxial, and the axis is a vertical straight line. This axis is defined as the axis of the self-locking rotary mechanical claw, and the radial direction of this axis is defined as radial. The motor shaft extends upwards; it also includes the following structure: The motor bracket plate (4) is fixedly connected to the housing (1) in the circumferential direction and fixedly connected to the motor (3) in the downward direction. The motor shaft extends out through the center hole. The opening and closing control board (5) is fixedly connected to the top of the motor shaft and rotates as a whole with the motor shaft. An arc-shaped opening and closing groove (6) is provided on the opening and closing control plate (5), which is open at the top and bottom, with one end adjacent to the axis and the other end adjacent to the circumferential edge of the opening and closing control plate (5); The positioning bearing (7) has its outer ring fixedly connected to the housing (1) and its inner ring connected to the mounting ring (8). Mounting ring (8) with a ratchet (9) on its lower surface. The ratchet teeth (10) of the ratchet (9) engage with the pawl (11). The pawl (11) is connected to the motor bracket plate (4) via a spring shaft (12), so that the ratchet (9) is only allowed to rotate continuously counterclockwise. The inner surface of the mounting ring (8) is provided with a radial arc-shaped rotation control protrusion (14), which together with the rotation control wheel (16) and the rotation control plate (17) form a one-way transmission groove (15); the rotation control wheel (16) is fixed to the motor shaft, and the rotation control plate (17) is radially fixed to the outer circumference of the rotation control wheel (16) and extends into the one-way transmission groove (15). Connecting rod (18), with mounting ring (8) at the lower end and fixing plate (19) at the upper end; Fixed plate (19), upward connected to slide groove (20); The slide groove (20) extends radially, and the slide rail (21) passes through the slide groove (20) and slides radially with the slide groove (20); The connecting seat (22) is fixed to the slide rail (21) at the bottom and connected to the clamp (24) at the top. The sliding pin (23) passes vertically through the arc-shaped opening and closing groove (6), with its lower end connected to the radial inner end of the connecting seat (22) and its upper end connected to the clamp (24).

2. The mechanical gripper according to claim 1, characterized in that: The arc-shaped opening and closing groove (6) is symmetrically arranged in three or more grooves with the axis as the center.

3. The mechanical gripper according to claim 1, characterized in that: The mounting ring (8) is integrally formed with the ratchet (9), and the radial outer end of the ratchet (10) is flush with the circumferential outer surface of the mounting ring (8).

4. The mechanical gripper according to claim 1, characterized in that: Two rotation control protrusions (14) are symmetrically arranged around the axis, and the one-way transmission grooves (15) correspond one-to-one with the rotation control plate (17).

5. The mechanical gripper according to claim 1, characterized in that: The lower end of the sliding pin (23) is connected to the connecting seat (22), and the upper end is connected to the gripper (24). The top of the radially outer end of the connecting seat (22) is higher than the opening and closing control plate (5).

6. The mechanical gripper according to claim 1, characterized in that: The diameter of the central hole of the motor bracket plate (4) is larger than the outer diameter of the motor shaft. The motor (3) and the housing (1) below it form a heat dissipation cavity. The bottom wall of the housing (1) is provided with heat dissipation holes (2).

7. The mechanical gripper according to claim 1, characterized in that: The connecting rod (18) is a round copper column with four rods evenly distributed around the circumference. The lower end is connected to the mounting ring (8), and the upper end is connected to the fixing plate (19).

8. The mechanical gripper according to claim 1, characterized in that: The groove (20) has its opening facing upwards, and the lower middle part of the slide rail (21) slides through the groove (20), while the upper part is fixed to the connecting seat (22).

9. The mechanical gripper according to claim 1, characterized in that: The bottom of the gripper (24) is a horizontal connecting part, which is fixedly connected to the connecting seat (22) and the sliding pin (23). Multiple grippers (24) are symmetrically distributed in the center.

10. The mechanical gripper according to claim 1, characterized in that: The outer ring of the positioning bearing (7) is fixed to the housing (1), and the inner ring is fixed to the mounting ring (8), so that the mounting ring (8) can rotate relative to the housing (1).

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