Hybrid link adaptive compliant fixture

Abstract

This invention relates to a hybrid linkage adaptive flexible clamp, comprising a conveyor belt base plate. Two fixed supports, one in front and one behind, are mounted on the base plate. A pair of clamping mechanisms, distributed on the left and right sides and capable of synchronously moving towards or away from each other by a motor, are connected between the two fixed supports. Each clamping mechanism includes a clamping plate support. Several flexible air cushions and locking plates are arranged along the length of the clamping plate support on the side facing the center. The upper end of each locking plate is hinged to the clamping plate support, and a spring connects the lower outer end of the locking plate to the clamping plate. This invention's hybrid linkage adaptive flexible clamp exhibits high adaptability to different types of objects, evenly distributing the clamping force and fundamentally eliminating stress concentration. It can absorb minor impacts and vibrations during loading, unloading, or conveying, preventing damage to objects due to rigid collisions. Furthermore, by controlling the motor to output a constant torque, it achieves constant force clamping, maintaining high clamping stability.

Description

Technical Field

[0001] This invention relates to the field of clamping technology, and in particular to a hybrid linkage adaptive flexible clamp. Background Technology

[0002] As the end-efficiency component of an automated production line, the performance of the fixture directly determines the system's adaptability and operational quality. In current industrial applications, traditional fixtures mostly adopt a rigid structural design, and their working principle is based on a preset mechanical trajectory and a fixed contact surface. Although this design has high positioning accuracy, it exposes some shortcomings when dealing with unstructured and diverse work objects.

[0003] Rigid fixtures have poor shape adaptability and struggle to handle diverse geometric objects. Traditional rigid fixtures are typically customized for workpieces of specific shapes, with fixed curved or flat clamping surfaces lacking deformation capability. When handling irregularly shaped castings, curved glass, or workpieces of varying sizes, the contact area between the fixture and the workpiece is very limited, easily leading to unstable clamping or decreased positioning accuracy. They also struggle to meet the compatibility requirements of different production lines for various types of workpieces. Furthermore, rigid fixtures exhibit localized stress concentration, easily damaging the workpiece. The metal or hard polymer materials of rigid fixtures lack cushioning when in contact with the workpiece, with clamping forces often concentrated at a few points or in a small area. This stress concentration easily causes scratches, indentations, or even breakage on the workpiece surface. They are also ineffective at completely clamping brittle or soft objects such as ceramics, glass, precision electronic components, fruits and vegetables, and fresh produce. Additionally, rigid fixtures have low changeover efficiency and are difficult to adapt to flexible manufacturing systems. In traditional production models, product changeovers often require physically replacing the entire fixture set and performing complex adjustments and alignment operations again. This process typically takes several hours or even days and requires a large inventory of specialized fixtures, which not only ties up capital but also severely restricts the production efficiency of the production line.

[0004] Patent research revealed that a Chinese invention patent (publication number CN119188627A) proposes a manual flexible clamping module with manual rapid positioning and elastic adaptive design as its core. Its innovative structure, through a combination of an "inverted T-shaped lifting chuck + positioning handle," achieves tool-free rapid sliding and locking of the clamping unit, significantly improving production efficiency. It uses multi-layered nested semi-circular rubber pillars as the clamping contact surface, utilizing the bending deformation of the rubber rods as a force transmission mechanism to achieve adaptive fitting and elastic buffering of the workpiece shape. This solution is simple in structure and low in cost, effectively avoiding workpiece damage caused by rigid clamping. However, because it relies entirely on manual operation, it cannot be integrated into automated production lines. Furthermore, the clamping force is determined by the passive deformation of the elastic element, making precise control difficult and resulting in low clamping stability. Another patent (publication number CN112454414A) provides an adaptive clamp based on a single power source drive. A rotating mechanism drives a worm gear, which in turn drives the connecting gears and eccentric connecting rods in multiple gripper mechanisms, achieving precise synchronous linkage of all grippers. This structure also functions as both an external clamping device and an internal support for the hollow structure. It integrates a pressure sensor for real-time sensing and closed-loop control of the clamping force, and the gripper position is adjustable along the base, exhibiting high integration, control accuracy, and adaptability to various working conditions. However, the overall structure is complex, requiring high precision in the machining and assembly of components, resulting in high manufacturing costs. Furthermore, the contact surface between the clamping arm and the workpiece remains rigid, which, when dealing with complex curved surfaces or fragile workpieces, offers less adaptive fitting capability than flexible material solutions, posing a risk of localized stress concentration. Therefore, to overcome these shortcomings, designing a flexible fixture that is highly adaptable, structurally simple, and reliable is crucial. Summary of the Invention

[0005] In view of this, the purpose of the present invention is to provide a hybrid linkage adaptive flexible clamp that can maintain high clamping stability, has high adaptability to different types of objects, and evenly distributes clamping force to prevent damage to objects caused by rigid collisions.

[0006] The present invention is implemented using the following scheme: a hybrid linkage adaptive flexible clamp, including a conveyor belt base plate, on which two fixed supports are provided, one in front and one behind. A pair of clamping mechanisms distributed on the left and right sides and capable of synchronously moving towards or away from each other by a motor are connected between the two fixed supports. The clamping mechanism includes a clamping bracket. The clamping bracket has a plurality of flexible air cushions and locking plates arranged along the length direction of the clamping bracket on the side facing the middle. The upper end of the locking plate is hinged to the clamping bracket, and a spring is connected between the outer side of the lower end of the locking plate and the clamping plate.

[0007] Furthermore, the upper part of the clamping plate bracket is provided with a clamping plate connecting rod parallel to the length direction of the clamping plate, and the upper end of the locking plate is provided with a hinge hole for the clamping plate connecting rod to pass through; the upper end of the locking plate extends upward to a buckling part that bends towards the middle.

[0008] Furthermore, adjacent locking plates are separated by at least one flexible air cushion; both the locking plates and the clamping parts have flexible gaskets on their working surfaces.

[0009] Furthermore, a spring retaining sleeve is fixedly connected to the lower end of the locking plate, and an outwardly extending spring connecting rod is fixedly inserted into the spring retaining sleeve, with the spring sleeved on the spring connecting rod.

[0010] Furthermore, the clamping plate bracket has clamping plate sliders at both ends, and the fixed bracket has a sliding groove that slides with the clamping plate sliders.

[0011] Furthermore, at least one of the fixed supports is provided with a motor drive device for driving the movement of the clamping plate mechanism. The motor drive device is mounted on the fixed support via a connecting rod bracket. The motor drive device includes a drive motor, which drives the clamping plate mechanism to move via a crank-slider mechanism.

[0012] Furthermore, the crank-slider mechanism includes a drive link A and a drive link B. One end of the drive link A is connected to the main shaft of the drive motor, and the other end is hinged to one end of the drive link B. The other end of the drive link B is slidably connected to the link bracket and connected to the corresponding end of the clamping plate bracket.

[0013] Furthermore, the other end of the driving link B is fixedly connected to a link fixing column, the link fixing column is slidably connected to the link bracket, and the link bracket is provided with a guide groove that slidably engages with the link fixing column; the other end of the driving link B is connected to the corresponding end of the clamping plate bracket via a link connecting column.

[0014] Furthermore, a pair of connecting base plates are connected between the bottom ends of the two fixed brackets, and the connecting base plates are clamped and fixed to the side edge of the conveyor belt base plate by quick-release blocks.

[0015] Compared with the prior art, the present invention has the following advantages: The hybrid linkage adaptive flexible clamp of the present invention can be quickly installed on the conveyor belt, has strong adaptability and simple structure; the flexible air cushion and locking plate hybrid clamping method flexibly clamps the objects on the transmission belt, has high adaptability to different types of objects, evenly distributes the clamping force, fundamentally eliminates stress concentration, can absorb the small impacts and vibrations of objects during loading, unloading or conveying, prevents damage to objects caused by rigid collisions, and achieves constant force clamping by controlling the motor to output constant torque, which can maintain high clamping stability.

[0016] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below through specific embodiments and related drawings. Attached Figure Description

[0017] Figure 1 This is a perspective view of the overall structure of an embodiment of the present invention; Figure 2 This is a perspective view of the motor drive device structure according to an embodiment of the present invention; Figure 3 This is a three-dimensional view of the clamping plate mechanism structure according to an embodiment of the present invention; Figure 4 This is a diagram showing the transition between the open and clamped states of the flexible clamp according to an embodiment of the present invention; Explanation of the numbers in the diagram: 1-Motor drive device, 2-First fixed bracket, 3-Clamping plate mechanism A, 4-Second fixed bracket, 5-Conveyor belt base plate, 6-Quick release block, 7-Clamping plate mechanism B, 201-Drive motor, 202-Motor bracket, 203-Drive connecting rod A, 204-Drive connecting rod B, 205-Connecting rod fixing column, 206-Connecting rod connecting column, 207-Connecting rod locking plate, 208-Connecting rod bracket, 301-Clamping plate bracket, 302-Clamping plate slider, 303-Clamping plate connecting rod, 304-Clamping part, 305-Flexible gasket, 306-Spring, 307-Spring connecting rod, 308-Spring fixing sleeve, 309-Locking plate, 310-Flexible air cushion. Detailed Implementation

[0018] It should be noted that the following detailed descriptions are exemplary and intended to provide further explanation of this application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0019] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0020] like Figures 1-4As shown, a hybrid linkage adaptive flexible clamp includes a conveyor belt base plate 5. The conveyor belt base plate 5 is provided with two fixed supports (i.e., the first fixed support 2 and the second fixed support 4) located one in front and one behind. A pair of clamping mechanisms (i.e., clamping mechanism A3 and clamping mechanism B7) are connected between the two fixed supports and are distributed on the left and right sides and can be driven by a motor to move synchronously towards or away from each other. The clamping mechanism includes a clamping bracket 301. The clamping bracket 301 is provided with a plurality of flexible air cushions 310 and locking plates 304 arranged along the length direction of the clamping bracket on the side facing the middle. The upper end of the locking plate 304 is hinged to the clamping bracket, and the lower outer side of the locking plate 304 is connected to the clamping plate with a spring 306.

[0021] When an object needs to be clamped, clamping mechanisms A3 and B7 move inward (towards the center) to apply a uniform squeezing force to the object, which is suitable for lighter and more fragile objects. When clamping a heavier object, the torque of the drive motor is increased, the locking spring is compressed and squeezed inward, and the external structure rotates inward to fasten to the object. At the same time, the squeezing force applied to the object can be controlled by adjusting the compression of the spring.

[0022] Compared to ordinary flexible grippers and rigid clamps, this clamping mechanism utilizes gradient flexible materials in key areas where it contacts the workpiece. For extremely fragile objects, a flexible air cushion is used for gripping, while locking plates assist in gripping heavier objects. This invention features passive compliance; the flexible air cushion undergoes elastic deformation upon contact with the workpiece, automatically adjusting the contact profile according to the workpiece's irregular curved surface or dimensional tolerances. This significantly increases the actual contact area, achieving a transition from point / line contact to surface contact, thereby evenly distributing the clamping force and fundamentally eliminating stress concentration. Furthermore, the installation of the air cushion enhances the dynamic cushioning of the clamp. The flexible air cushion itself possesses viscoelasticity, absorbing minor impacts and vibrations during loading, unloading, or conveying, preventing surface scratches, indentations, or internal micro-cracks caused by rigid collisions.

[0023] This invention utilizes an optimized clamping mechanism, combined with locking plates, to form a multi-dimensional mechanical constraint system. The clamping mechanism features a wide design, increasing the contact area with the workpiece, effectively dispersing the clamping force and preventing excessive local pressure. The locking plates assist in positioning and locking the object during clamping, restricting the displacement and rotational freedom of the object during processing or handling, absorbing external vibrations, and preventing slippage due to inertial forces. Simultaneously, a constant torque output from the motor controls the clamping mechanism and locking plates to maintain constant force clamping. This dual protection mechanism ensures high clamping stability even under eccentric loads or high-speed motion conditions on a transmission belt, making it suitable for high-precision positioning machining or assembly scenarios requiring constant output from the fixture.

[0024] In this embodiment, the upper part of the clamping plate bracket 301 is provided with a clamping plate connecting rod 303 parallel to the length direction of the clamping plate, and the upper end of the locking piece 304 is provided with a hinge hole for the clamping plate connecting rod to pass through; the upper end of the locking piece 304 extends upward to form a clamping part 304 that bends toward the middle side.

[0025] In this embodiment, two adjacent locking plates are separated by at least one flexible air cushion; both the locking plates and the clamping part have flexible gaskets 5 on their working surfaces.

[0026] In this embodiment, a spring fixing sleeve 308 is fixedly connected to the lower end of the locking piece 309, and an outwardly extending spring connecting rod 307 is fixedly inserted into the spring fixing sleeve 308, with the spring 306 sleeved on the spring connecting rod.

[0027] In this embodiment, the clamping plate bracket is provided with clamping plate sliders 302 at both ends, and the fixed bracket is provided with a sliding groove that slides with the clamping plate sliders.

[0028] In this embodiment, one of the fixed supports (i.e., the first fixed support 2) is provided with a motor drive device 1 for driving the movement of the clamping mechanism. The motor drive device 1 is mounted on the first fixed support 2 via a connecting rod support 208. The motor drive device 1 includes a drive motor 201, which drives the clamping mechanism to move via a crank-slider mechanism.

[0029] In this embodiment, the crank-slider mechanism includes a drive link A203 and a drive link B204. One end of the drive link A203 is connected to the main shaft of the drive motor 201, and the other end is hinged to one end of the drive link B204. The other end of the drive link B204 is slidably connected to the link bracket 208 and connected to the corresponding end of the clamp bracket 301.

[0030] In this embodiment, two sets of crank-slider mechanisms are provided, each corresponding to a different clamping plate mechanism. The two sets of crank-slider mechanisms are centrally symmetrically distributed with the main shaft of the drive motor 201 as the center. To simplify the structure, the drive connecting rods A of the two sets of crank-slider mechanisms are connected as one unit, that is, in the same drive connecting rod A203. The middle part of the drive connecting rod A203 is fixed to the main shaft of the drive motor 201 by the connecting rod locking piece 207.

[0031] In practice, motor drive devices can be installed on both fixed supports, and the motors of the two sets of motor drive devices can work synchronously to ensure that the clamping mechanism is evenly stressed at both ends and avoid jamming.

[0032] In this embodiment, the other end of the driving link B204 is fixedly connected to a link fixing post 205. The link fixing post 205 is slidably connected to a link bracket 208, and the link bracket 208 is provided with a guide groove that slidably engages with the link fixing post 205. The other end of the driving link B204 is connected to the corresponding end of the clamping plate bracket via a link connecting post 206. The driving link is driven by a motor, which converts the rotational motion of the motor into the reciprocating motion of the link end to achieve translational control of the clamping mechanism. The guide groove limits the movement range of the clamping mechanism by limiting the link fixing post at the end of the driving link B. The magnitude of the output clamping torque is controlled by the driving motor to achieve constant force clamping of the clamped object.

[0033] In this embodiment, a pair of connecting base plates are connected between the bottom ends of the two fixed brackets. The connecting base plates are clamped and fixed to the side edge of the conveyor belt base plate by quick-release blocks 6. The quick-release blocks 6 are U-shaped, with the connecting base plates and the side edge of the conveyor belt base plate clamped in the middle. Locking screws are provided on the upper and lower sides of the quick-release blocks, and the two locking screws respectively tighten the connecting base plates and the side edge of the conveyor belt base plate. This enables quick installation on the conveyor belt and facilitates subsequent maintenance and disassembly. This invention designs a quick-release block suitable for conveyor belts, fixing the fixture to the conveyor belt with locking screws, combining speed and reliability. It changes the cumbersome process of finding tools, loosening screws, and re-aligning during production line changeovers, compressing changeover auxiliary time. It is suitable for flexible manufacturing units with multiple varieties and small batches, significantly improving the overall efficiency of the equipment and solving the problem of time-consuming and labor-intensive traditional fixture replacement.

[0034] The flexible clamp is fixed to the conveyor belt base plate via quick-release blocks. The object is then placed in the clamp. When clamping is required, the drive motor of the flexible clamp rotates, driving the drive linkage and clamping plate mechanism to hold the object. When clamping fragile or lightweight objects, the drive motor outputs a smaller torque. The flexible air cushion of the clamping plate contacts the object, automatically adjusting its contact profile according to the shape of the contacted surface, increasing the actual contact area and thus evenly distributing the clamping force and eliminating stress concentration. When clamping heavier, irregularly shaped, or vibrating objects, the drive motor outputs a larger torque. The locking plate of the clamp contacts and rotates, assisting in positioning and locking the object, limiting its displacement. Simultaneously, the spring of the locking plate is compressed, providing greater compressive force to the clamped object. The dual, multi-dimensional clamping of the clamping plate air cushion and locking plate further enhances the clamping stability of the fixture.

[0035] Unless otherwise stated, if any of the technical solutions disclosed in this invention specify a numerical range, then the disclosed numerical range is a preferred numerical range. Anyone skilled in the art should understand that the preferred numerical range is merely one among many feasible numerical values ​​that has a more obvious or representative technical effect. Because there are many numerical values, it is impossible to list them all. Therefore, this invention discloses only some numerical values ​​to illustrate the technical solutions of this invention. Furthermore, the numerical values ​​listed above should not constitute a limitation on the scope of protection of this invention.

[0036] If this invention discloses or relates to mutually fixedly connected components or structural parts, then, unless otherwise stated, a fixed connection can be understood as: a detachable fixed connection (e.g., using bolts or screws), or a non-detachable fixed connection (e.g., riveting, welding). Of course, mutually fixed connections can also be replaced by an integral structure (e.g., manufactured in one piece using a casting process) (except where it is obviously impossible to use an integral molding process).

[0037] In addition, unless otherwise stated, the terms used in any of the technical solutions disclosed in this invention to indicate positional relationships or shapes include states or shapes that are similar to, close to, or approximate with those states or shapes.

[0038] Any component provided by this invention can be assembled from multiple individual components or can be a single component manufactured by a one-piece molding process.

[0039] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any other way. Any person skilled in the art may make changes or modifications to the above-disclosed technical content to create equivalent embodiments. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the protection scope of the present invention.

Claims

1. A hybrid link self-adapting flexible fixture, characterized by: The system includes a conveyor belt base plate, on which two fixed supports are provided, one in front and one behind. A pair of clamping mechanisms, distributed on the left and right sides and capable of synchronously moving towards or away from each other by a motor, are connected between the two fixed supports. Each clamping mechanism includes a clamping bracket, and on the side of the clamping bracket facing the middle, there are several flexible air cushions and locking plates arranged along the length of the clamping bracket. The upper end of the locking plate is hinged to the clamping bracket, and a spring is connected between the outer side of the lower end of the locking plate and the clamping plate.

2. The hybrid linkage adaptive flexible clamp according to claim 1, characterized in that: The upper part of the clamping plate bracket is provided with a clamping plate connecting rod parallel to the length direction of the clamping plate, and the upper end of the locking plate is provided with a hinge hole for the clamping plate connecting rod to pass through; the upper end of the locking plate extends upward to a buckling part that bends towards the middle.

3. The hybrid linkage adaptive flexible clamp according to claim 2, characterized in that: Adjacent locking plates are separated by at least one flexible air cushion; both the locking plates and the clamping parts have flexible gaskets on their working surfaces.

4. The hybrid linkage adaptive flexible clamp according to claim 1, characterized in that: The lower end of the locking plate is fixedly connected to a spring fixing sleeve, and an outwardly extending spring connecting rod is fixedly inserted into the spring fixing sleeve. The spring is sleeved on the spring connecting rod.

5. The hybrid linkage adaptive flexible clamp according to claim 1, characterized in that: The clamping plate bracket has clamping plate sliders at both ends, and the fixed bracket has a sliding groove that slides with the clamping plate sliders.

6. The hybrid linkage adaptive flexible clamp according to claim 1, characterized in that: At least one of the fixed supports is provided with a motor drive device for driving the movement of the clamping plate mechanism. The motor drive device is mounted on the fixed support via a connecting rod bracket. The motor drive device includes a drive motor, which drives the clamping plate mechanism to move via a crank-slider mechanism.

7. The hybrid linkage adaptive flexible clamp according to claim 5, characterized in that: The crank-slider mechanism includes a drive link A and a drive link B. One end of the drive link A is connected to the main shaft of the drive motor, and the other end is hinged to one end of the drive link B. The other end of the drive link B is slidably connected to the link bracket and connected to the corresponding end of the clamp bracket.

8. The hybrid linkage adaptive flexible clamp according to claim 6, characterized in that: The other end of the driving link B is fixedly connected to a link fixing column, and the link fixing column is slidably connected to the link bracket. The link bracket is provided with a guide groove that slidably engages with the link fixing column. The other end of the driving link B is connected to the corresponding end of the clamping plate bracket via a link connecting column.

9. The hybrid linkage adaptive flexible clamp according to claim 1, characterized in that: A pair of connecting base plates are connected between the bottom ends of the two fixed brackets, and the connecting base plates are clamped and fixed to the side edge of the conveyor belt base plate by quick-release blocks.

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