A multifunctional actuator based on adjustable radial flexible pneumatic gripper

Abstract

The utility model relates to a kind of multifunctional actuators based on adjustable radial flexible pneumatic clamping jaw.The improvement points are as follows: ①including substrate, symmetrically mobile installation's first movable plate and second movable plate, and radial adjusting assembly;②radial adjusting assembly is driven double movable plate along slide rail synchronous forward / reverse translation by positive and negative tooth screw, and the diameter of annular grabbing array is adjusted;③six groups of oil-resistant nitrile rubber flexible pneumatic clamping jaw are distributed below movable plate, form centripetal closed force field, and the anti-skid of clamping surface convex texture is enhanced;④pneumatic shear has inner concave arc blade edge, and supports shearing-grabbing collaborative work;⑤actuator is integrated in six-axis robot wrist, and realizes global operation with mobile platform.The utility model realizes the continuous stepless adjustment of the diameter of annular grabbing array, adapts the grabbing of different size products or workpieces, and has the advantages of redundancy slide rail anti-overturning, force field distribution uniformity reduces the breakage rate of fragile parts, multifunctional integration improves operation continuity and the like.

Description

Technical Field

[0001] This utility model relates to the field of automation equipment technology, specifically to a multifunctional actuator based on an adjustable diameter flexible pneumatic gripper. Background Technology

[0002] In the field of automated gripping, adaptive flexible pneumatic grippers are widely used due to their flexible contact characteristics. However, existing grippers employ a cylinder-driven multi-fin synchronous opening and closing design, and their maximum expansion diameter is limited by the effective stroke of the cylinder and the physical length of the gripper arm, resulting in structural limitations on the gripping range. When handling workpieces with significant size differences, such as strawberries (φ30mm) and citrus fruits (φ120mm) in agricultural harvesting, or small packages (<50mm) and standard boxes (>300mm) in logistics sorting, existing adaptive flexible pneumatic grippers have the following technical problems: ① Frequent replacement of the execution fixture or addition of a dedicated execution mechanism is required, leading to decreased production line flexibility and increased equipment costs; ② As the gripping range expands, the uniformity of the gripping force distribution decreases significantly, the force transmission chain lengthens, causing local stress concentration and increasing the risk of breakage of fragile workpieces.

[0003] Existing solutions for extending the gripping range have the following shortcomings: ① Mechanical series solutions (e.g., stacked extension rod structures): Although the opening and closing diameter can be increased, it leads to a decrease in the stiffness of the end effector, which poses a risk of instability when handling heavy workpieces; ② Modular replacement solutions: The fixture switching process requires interruption of continuous operation, increasing the complexity of system management and downtime; ③ Multi-jaw independent diameter adjustment solutions: Multiple independent pneumatic control systems need to be configured, which significantly increases the system complexity and failure rate.

[0004] Therefore, there is an urgent need to develop a new actuator architecture with dynamic diameter adjustment capability, balanced force field distribution and multi-functional integration characteristics to overcome the rigidity range constraints of traditional grippers. Utility Model Content

[0005] In order to overcome the above-mentioned defects of existing automated gripping devices, this utility model provides a multi-functional actuator based on an adjustable diameter flexible pneumatic gripper.

[0006] The technical solution adopted in this utility model is as follows: A multifunctional actuator based on adjustable diameter flexible pneumatic grippers includes: a base plate; a first movable plate and a second movable plate, movably mounted on the base plate; an adjusting component that drives the first movable plate and / or the second movable plate to move relative to each other; and multiple sets of flexible pneumatic grippers, evenly arranged below the first movable plate and the second movable plate, forming a ring-shaped gripping array facing the center of the base plate; wherein, the adjusting component adjusts the distance between the first movable plate and the second movable plate to adjust the spatial size of the ring-shaped gripping array.

[0007] Preferably, the diameter adjustment assembly includes: a first slider and a second slider, respectively fixed to the first movable plate and the second movable plate; a slide rail, fixed to the base plate, forming a sliding pair with the first slider and the second slider; a first nut and a second nut, respectively fixed to the first movable plate and the second movable plate; a forward and reverse threaded screw, the left-hand threaded section of which forms a threaded pair with the first nut, and the right-hand threaded section of which forms a threaded pair with the second nut; and a diameter adjustment motor, the output shaft of which is connected to the forward and reverse threaded screw; wherein the diameter adjustment motor drives the forward and reverse threaded screw to rotate forward / reverse, thereby causing the first movable plate and the second movable plate to move synchronously in opposite directions along the slide rail, so as to adjust the spatial size of the annular gripping array.

[0008] Preferably, the slide rail consists of two sets of parallel linear slide rails, with two first sliders and two second sliders mounted on the bottom of each of the first and second movable plates, forming a redundant guide structure.

[0009] Preferably, it further includes: a pneumatic shear, fixed to the substrate, which is a pneumatically driven interlaced double-blade shear mechanism, wherein the shearing center axis of the pneumatic shear is parallel to the center axis of the annular gripping array.

[0010] Preferably, the pneumatic shear includes a fixed blade and a moving blade, with the cutting edge having an inwardly concave arc shape; the moving blade is driven by a shearing cylinder.

[0011] Preferably, it further includes: a six-axis robot having a base, a rotary mechanism, a shoulder joint, an elbow joint, a wrist pitch joint, a wrist swing joint, and a wrist rotation joint connected in sequence; the base plate is integrated at the end of the wrist rotation joint.

[0012] Preferably, it also includes: a platform for mounting the air pump assembly, the power distribution box, and the six-axis robot.

[0013] Preferably, it further includes: a mobile platform, which is a wheeled vehicle or a rail vehicle, having a preset travel path for transporting the platform.

[0014] Preferably, the flexible pneumatic gripper is molded from oil-resistant nitrile rubber, and the gripping surface has raised textures.

[0015] Preferably, the number of flexible pneumatic grippers is six, which are evenly distributed in a ring below the first movable plate and the second movable plate.

[0016] This utility model has the following beneficial effects: 1. Adaptive gripping range: The synchronous diameter adjustment mechanism driven by the forward and reverse screws requires only a single motor to control the two moving plates to move in opposite directions, realizing continuous stepless adjustment of the diameter of the ring gripping array, significantly expanding the workpiece size adaptation range of a single actuator, without the need to change fixtures or interrupt operations. 2. Redundant linear guide rail: The sliding pair consisting of double rails and four sliders ensures anti-overturning stability during large-span diameter adjustment and avoids the risk of instability during the handling of heavy workpieces; 3. Uniform force field distribution: Six flexible pneumatic grippers evenly distributed in a ring form a closed force field, realizing three-dimensional self-centering gripping and eliminating local stress concentration; the raised texture on the gripper surface and the flexible nitrile rubber material work together to increase the friction coefficient while dispersing the contact pressure, reducing the breakage rate of fragile workpieces such as fruits. 4. Multifunctional integration and continuous operation: The base plate integrates a pneumatic shearing mechanism with a concave arc blade and a direct-drive design of the shearing cylinder, which supports shearing-grip collaborative operations (such as picking fruit with branches or cutting packaging tape), reducing process changeover time; the six-axis robot, together with the mobile platform, forms a full-domain operation system, which uses wrist rotation joints to precisely position the actuators and realizes gripping / shearing composite operations under complex spatial trajectories. 5. System reliability and cost optimization: The diameter adjustment component only requires single-channel motor control, which reduces the gas / circuit complexity compared to multi-claw independent diameter adjustment solutions; the modular table integrates the air pump and power distribution box, supporting rapid maintenance and functional expansion, reducing the overall operation and maintenance cost of the equipment. Attached Figure Description

[0017] Figure 1 This is a perspective view of an embodiment of the present utility model.

[0018] Figure 2 This is a three-dimensional schematic diagram of the actuator component in an embodiment of this utility model.

[0019] Figure 3 This is an exploded view of the actuator component in an embodiment of this utility model.

[0020] In the diagram: 1-Baseboard; 2-First movable plate; 3-Second movable plate; 4-Flexible pneumatic gripper; 5-First slider; 6-Second slider; 7-Slide rail; 8-First nut; 9-Second nut; 10-Forward and reverse threaded screw; 11-Adjustable diameter motor; 12-Pneumatic shears; 13-Six-axis robot; 14-Tabletop; 15-Air pump assembly; 16-Power distribution box. Detailed Implementation

[0021] The present invention will be further described below with reference to the embodiments and accompanying drawings.

[0022] In the embodiments, such as Figures 1-3The diagram illustrates a multifunctional actuator based on adjustable-diameter flexible pneumatic grippers, primarily used in automated agricultural harvesting scenarios. It includes: a base plate 1; a first movable plate 2 and a second movable plate 3, movably mounted on the base plate 1; an adjusting assembly that drives the first movable plate 2 and / or the second movable plate 3 to move relative to each other; and multiple sets of flexible pneumatic grippers 4, evenly arranged below the first movable plate 2 and the second movable plate 3, forming a ring-shaped gripping array facing the center of the base plate 1. The adjusting assembly adjusts the distance between the first movable plate 2 and the second movable plate 3 to adjust the spatial dimensions of the ring-shaped gripping array. In this embodiment, the adjusting assembly dynamically adjusts the distance between the first movable plate 2 and the second movable plate 3, allowing the diameter of the ring-shaped gripping array to continuously adapt to agricultural products of different sizes (e.g., strawberries φ30mm to citrus φ120mm). The evenly distributed ring design of the flexible pneumatic grippers 4 forms a centripetal closed force field, ensuring uniform force on the fruit and reducing harvesting damage. The fixture-free switching characteristic significantly improves the continuity of the harvesting system.

[0023] In the embodiments, such as Figures 1-3 As shown, the diameter adjustment assembly includes: a first slider 5 and a second slider 6, respectively fixed to a first movable plate 2 and a second movable plate 3; a slide rail 7, fixed to a base plate 1, forming a sliding pair with the first slider 5 and the second slider 6; a first nut 8 and a second nut 9, respectively fixed to the first movable plate 2 and the second movable plate 3; a forward and reverse threaded screw 10, the left-hand threaded section of which forms a threaded pair with the first nut 8, and the right-hand threaded section of which forms a threaded pair with the second nut 9; and a diameter adjustment motor 11, the output shaft of which is connected to the forward and reverse threaded screw 10. The diameter adjustment motor 11 drives the forward and reverse threaded screw 10 to rotate forward / reverse, thereby causing the first movable plate 2 and the second movable plate 3 to move synchronously in opposite directions along the slide rail 7 to adjust the spatial size of the annular gripping array. The diameter adjustment motor 11 drives the forward and reverse threaded screw 10 to achieve bidirectional synchronous control from a single power source. When the first movable plate 2 and the second movable plate 3 move in opposite directions along the slide rail 7, the diameter change rate of the ring array doubles, shortening the diameter adjustment time. The screw nut transmission accuracy reaches ±0.1mm, ensuring the precise positioning of the fruit stem.

[0024] In the embodiments, such as Figures 1-3 As shown, the slide rail 7 consists of two sets of parallel linear slide rails. Two first sliders 5 and two second sliders 6 are mounted at the bottom of both the first movable plate 2 and the second movable plate 3, forming a redundant guide structure. The two slide rails 7 and the four sliders (first sliders 5 and second sliders 6) constitute an anti-overturning redundant structure, which improves lateral stiffness and prevents actuator instability caused by field bumps when gripping heavy fruits and vegetables (such as cantaloupes) with a maximum unfolding diameter (>300mm).

[0025] In the embodiments, such as Figures 1-3As shown, it also includes: a pneumatic shear 12, fixed to the base plate 1, which is a pneumatically driven staggered double-blade shear mechanism. The shearing center axis of the pneumatic shear 12 is parallel to the center axis of the annular gripping array. The pneumatic shear 12 includes a fixed blade and a moving blade, with the cutting edge being concave arc-shaped. The moving blade is driven by a shearing cylinder. The concave arc-shaped cutting edges of the fixed / moving blades of the pneumatic shear 12 cover the fruit stalk, and the shearing cylinder provides the closing force to cut the fruit branch or vine in one go. The center axis is coaxial with the gripper array, supporting shearing-gripping operations (e.g., gripping citrus fruits after cutting off the stalk), reducing process time.

[0026] In the embodiments, such as Figure 1 As shown, it also includes: a six-axis robot 13, which has a base, a rotary mechanism, a shoulder joint, an elbow joint, a wrist pitch joint, a wrist swing joint, and a wrist rotation joint connected in sequence; a base plate 1 is integrated at the end of the wrist rotation joint. The wrist rotation joint of the six-axis robot 13 drives the base plate 1 to achieve ±180° azimuth adjustment, which, together with the pitch / swing joint, improves the success rate of obstacle avoidance path planning in complex canopies, and keeps the blade of the pneumatic shears 12 perpendicular to the fruit stalk in any posture, improving the shearing qualification rate. The central axis of the gripper array is always perpendicular to the fruit growth plane, ensuring a symmetrical distribution of gripping force.

[0027] In the embodiments, such as Figure 1 As shown, it also includes: a platform 14 for mounting the air pump assembly 15, the power distribution box 16, and the six-axis robot 13; and a mobile platform, which is a wheeled vehicle or railcar with a preset travel path, for transporting the platform 14. The mobile platform, carrying the platform 14, enables inter-plant navigation. The air pump assembly 15 provides a constant pressure air source of 0.6 MPa to ensure the opening and closing response time of the grippers 4 under fluctuating field conditions. The power distribution box 16 integrates electrical control modules and overload protection devices. The modular platform 14 supports rapid maintenance and functional expansion, reducing the overall equipment operation and maintenance costs.

[0028] In this embodiment, the flexible pneumatic grippers 4 are molded from oil-resistant nitrile rubber, with raised textures on the gripping surface; there are six grippers, evenly distributed in a ring below the first movable plate 2 and the second movable plate 3. The six oil-resistant nitrile rubber grippers 4 form a 360° enveloping grip, and the raised textures increase the coefficient of friction to prevent dewy fruits from slipping off; the evenly distributed ring structure maintains a uniform force field even when the diameter is adjusted to its minimum, making it suitable for harvesting small fruits without damage.

[0029] The complete operation process of this embodiment in the agricultural harvesting scenario is as follows: ①System initialization: The air pump assembly 15 is started to establish a constant pressure air source of 0.6MPa. The power distribution box 16 supplies power to the six-axis robot 13 and the motor 11. The diameter adjustment motor 11 drives the forward and reverse threaded screws 10 to reverse, causing the first movable plate 2 and the second movable plate 3 to move towards each other, so that the flexible pneumatic gripper 4 retracts to the minimum diameter. The shearing cylinder of the pneumatic shear 12 is reset, and the moving blade is in the open state.

[0030] ② Target location and cutting operation: The mobile platform cruises along a preset path to the target plant. The six-axis robot 13 adjusts the orientation of the base plate 1 through the wrist rotation joint so that the concave arc-shaped blade of the pneumatic shears 12 is vertically aligned with the fruit stalk. The six-axis robot 13 moves along the pre-programmed trajectory, precisely guiding the fruit stalk between the fixed blade and the moving blade of the pneumatic shears 12. The shearing cylinder drives the moving blade to close, completing the shearing of the fruit stalk.

[0031] ③ Grip array diameter adjustment and positioning: The six-axis robot 13 switches its posture and positions the fruit 50mm above the central axis of the circular gripping array; the diameter adjustment motor 11 drives the forward and reverse threaded screws 10 to rotate forward, the left-hand threaded section drives the first nut 8 and the first movable plate 2 to move to the left, and the right-hand threaded section drives the second nut 9 and the second movable plate 3 to move to the right. The two sets of movable plates move synchronously in opposite directions along the slide rail 7, so that the six sets of flexible pneumatic grippers 4 expand to the preset diameter; the redundant guide structure (double slide rail 7 + four sliders) ensures that there is no overturning when adjusting the diameter over a large span.

[0032] ④ Flexible grasping and transfer: The six-axis robot 13 moves the base plate 1 downward, allowing the fruit to enter the grasping area; it drives the flexible pneumatic gripper 4 to descend to the height of the fruit stem separation point; the grasping cylinder retracts, and the oil-resistant nitrile rubber gripper 4 elastically wraps around the surface of the fruit, with raised textures providing anti-slip friction; the six-axis robot 13 transfers the fruit to the collection box, the grasping cylinder releases the fruit, and the rubber gripper 4 returns to its original position due to the elasticity of the material.

[0033] ⑤ Collaborative operation mode (optional): For fruits with branches, the pneumatic shears 12 and grippers 4 work together: first, the circular gripping array directly grips the fruit, and then the pneumatic shears 12 cuts the fruit branch in the same posture, saving the posture switching time of the six-axis robot 13.

[0034] Obviously, the above embodiments of this utility model are merely examples for illustrating the present utility model, and are not intended to limit the implementation of the present utility model. Other obvious variations or modifications derived from the essential spirit of the present utility model still fall within the protection scope of the present utility model.

Claims

1. A multifunctional actuator based on an adjustable-diameter flexible pneumatic gripper, characterized in that, include: substrate(1); The first movable plate (2) and the second movable plate (3) are movably mounted on the base plate (1); The diameter adjustment assembly drives the first movable plate (2) and / or the second movable plate (3) to move relative to each other; Multiple sets of flexible pneumatic grippers (4) are evenly arranged below the first movable plate (2) and the second movable plate (3) to form a ring gripping array facing the center of the substrate (1); The diameter adjustment component adjusts the distance between the first movable plate (2) and the second movable plate (3) to adjust the spatial size of the annular gripping array.

2. The multifunctional actuator based on an adjustable diameter flexible pneumatic gripper according to claim 1, characterized in that, The diameter adjustment component includes: The first slider (5) and the second slider (6) are fixed to the first movable plate (2) and the second movable plate (3), respectively. The slide rail (7) is fixed to the base plate (1) and forms a sliding pair with the first slider (5) and the second slider (6); The first nut (8) and the second nut (9) are fixed to the first movable plate (2) and the second movable plate (3), respectively. The positive and negative threaded screw (10) has a left-hand threaded section that forms a threaded pair with the first nut (8) and a right-hand threaded section that forms a threaded pair with the second nut (9); The output shaft of the adjustable diameter motor (11) is connected to the positive and negative thread screws (10) for transmission. The adjusting motor (11) drives the forward and reverse threaded screws (10) to rotate forward / reverse, thereby causing the first movable plate (2) and the second movable plate (3) to move synchronously in opposite directions along the slide rail (7) to adjust the spatial size of the annular gripping array.

3. The multifunctional actuator based on an adjustable diameter flexible pneumatic gripper according to claim 2, characterized in that, The slide rail (7) consists of two sets of parallel linear slide rails. The bottom of the first movable plate (2) and the second movable plate (3) are each equipped with two first sliders (5) and two second sliders (6) to form a redundant guide structure.

4. The multifunctional actuator based on an adjustable diameter flexible pneumatic gripper according to claim 1, characterized in that, Also includes: The pneumatic shear (12), fixed to the substrate (1), is a pneumatically driven interlaced double-blade shear mechanism. The shearing center axis of the pneumatic shear (12) is parallel to the center axis of the annular gripping array.

5. The multifunctional actuator based on an adjustable diameter flexible pneumatic gripper according to claim 4, characterized in that, The pneumatic shear (12) includes a fixed blade and a moving blade, with the cutting edge being concave arc-shaped; the moving blade is driven by a shearing cylinder.

6. The multifunctional actuator based on an adjustable diameter flexible pneumatic gripper according to any one of claims 1-5, characterized in that, Also includes: A six-axis robot (13) has a base, a rotary mechanism, a shoulder joint, an elbow joint, a wrist pitch joint, a wrist swing joint and a wrist rotation joint connected in sequence; The substrate (1) is integrated at the end of the wrist rotation joint.

7. The multifunctional actuator based on an adjustable diameter flexible pneumatic gripper according to claim 6, characterized in that, Also includes: The tabletop (14) is used to install the air pump assembly (15), the electrical control box (16), and the six-axis robot (13).

8. The multifunctional actuator based on an adjustable diameter flexible pneumatic gripper according to claim 7, characterized in that, Also includes: The mobile platform, which is a wheeled vehicle or a rail vehicle, has a preset travel path and is used to transport the platform (14).

9. The multifunctional actuator based on an adjustable diameter flexible pneumatic gripper according to claim 1, characterized in that, The flexible pneumatic gripper (4) is molded from oil-resistant nitrile rubber, and the gripping surface has raised textures.

10. The multifunctional actuator based on an adjustable diameter flexible pneumatic gripper according to claim 1, characterized in that, The number of flexible pneumatic grippers (4) is six, which are evenly distributed in a ring below the first movable plate (2) and the second movable plate (3).

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