Force-control self-adaptive clamping jaw

Abstract

The utility model discloses a force-control self-adaptive clamping jaw, which relates to the technical field of clamps and comprises a shell, a direct-drive motor fixed at the bottom of the shell, a ball screw driven by the direct-drive motor, a feed screw nut connecting rod connected above the ball screw, a first connecting rod fixed by the feed screw nut connecting rod, a second connecting rod connected with the first connecting rod, and a third connecting rod connected with the second connecting rod. The third connecting rod is connected with a fifth connecting rod, one side of the fourth connecting rod is fixed to the shell, the other side of the fourth connecting rod is fixed to the fifth connecting rod, and the clamping jaw is fixed to the upper portion of the fifth connecting rod. The force-controlled self-adaptive clamping jaw is provided with the conversion pin, the functions of parallel clamping and self-adaptive clamping can be achieved only by inserting or pulling out the conversion pin, and the force-controlled self-adaptive clamping jaw is multifunctional.

Description

Technical Field

[0001] This utility model relates to the field of clamping technology, and in particular to a force-controlled adaptive gripper. Background Technology

[0002] Grippers are an indispensable component in the fields of automation and intelligent manufacturing. The force control function of grippers is very important, as it enables the adjustment of gripping force. For example, when encountering fragile or soft items, they can be clamped without damaging the items through delicate torque control, and better interact with the outside world. Most force control grippers on the market use tension and compression sensors or other force feedback mechanisms to measure the gripping force and achieve precise closed-loop force control.

[0003] Most grippers on the market are designed to grip regular objects (cuboids) and perform well. However, when dealing with irregular objects, such as cylinders or irregular polygons, the gripping stability drops significantly due to the reduced gripping friction area. The purpose of adaptive grippers is to increase the gripping area by passively increasing the degree of freedom when gripping irregular objects, thereby achieving better gripping stability.

[0004] In the prior art, a force-controlled gripper disclosed in patent publication number CN205766201U relies on a force feedback device or force sensor to achieve precise gripping force output, which usually increases the component cost of the gripper by more than double, and strain gauges also increase the failure rate of the gripper. Utility Model Content

[0005] The purpose of this invention is to solve the problem that existing grippers do not have a switching mode. This invention is equipped with a conversion pin, which can realize both parallel gripping and adaptive gripping functions simply by inserting or removing the conversion pin, thus providing a multi-functional force-controlled adaptive gripper.

[0006] Another objective of this invention is to solve the problem of complex existing gripper structures. This invention uses direct drive motor current feedback to achieve gripping force control, avoiding the use of additional force sensors, and provides a low-cost force-controlled adaptive gripper.

[0007] To achieve the above objectives, this utility model provides the following technical solution: a force-controlled adaptive gripper, comprising a housing, a direct drive motor fixed at the bottom of the housing, the direct drive motor driving a ball screw, a screw nut connecting rod connected above the ball screw, a first connecting rod fixed to the screw nut connecting rod, the first connecting rod connecting to a second connecting rod, the second connecting rod connecting to a third connecting rod, the third connecting rod connecting to a fifth connecting rod, a fourth connecting rod fixed on one side to the housing and on the other side to the fifth connecting rod, and a gripper fixed above the fifth connecting rod.

[0008] Preferably, the conversion pin is fixed between the second link and the third link.

[0009] Preferably, when clamping in parallel, the conversion pin is inserted, and the line connecting the two ends of the second and third links is parallel to the fourth link.

[0010] Preferably, during adaptive gripping, the retaining rings in the third and fifth links apply a small force to keep the grippers parallel, and the grippers overcome the force of the retaining rings so that the fourth link and the grippers grip the object surface tightly.

[0011] Preferably, the first link, second link, third link, fourth link, and fifth link are fixed together by a fixing pin.

[0012] Preferably, the connecting parts on both sides of the third link are thicker, and the middle part has a concave structure.

[0013] Preferably, the top of the ball screw is a top bearing housing, and a deep groove ball bearing is installed inside the top bearing housing.

[0014] Preferably, fasteners are provided on the top bearing housing.

[0015] Preferably, a rubber pad is provided on one side of the gripper, and the gripper as a whole is L-shaped.

[0016] Preferably, the lead screw and nut connecting rod are fixed to the ball screw using a lead screw and nut.

[0017] Compared with existing technologies, the advantages of this invention are as follows: By setting a conversion pin, this invention allows switching between parallel gripping and adaptive gripping with a simple insertion or removal operation, enabling the gripper to adapt to different scenarios and greatly enhancing its versatility to meet diverse working conditions. It employs direct-drive motor current feedback control of the gripping force, eliminating the need for external force sensors, effectively reducing costs, simplifying the structure, and improving reliability. The use of ball screw transmission reduces transmission backlash, making the gripping action smoother, and combined with the adaptive gripping mechanism, ensures stable and reliable gripping of irregular objects. The built-in transmission and elastic elements prevent damage or jamming of exposed parts, comprehensively improving safety. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the main structure of this utility model.

[0019] Figure 2 This is a schematic diagram of the internal structure of this utility model.

[0020] Figure 3 This is a top view of the present invention.

[0021] Figure 4 This is a cross-sectional view AA of the present invention.

[0022] Figure 5 This is an enlarged view of the present invention, shown in Figure C.

[0023] In the diagram: 1. Deep groove ball bearing; 11. Fixing pin; 12. Clamping jaw; 13. Rubber pad; 2. Direct drive motor; 21. Top bearing housing; 22. Fastener; 23. Fourth connecting rod; 24. Third connecting rod; 25. Fifth connecting rod; 3. Screw fixing flange; 26. Converter pin; 4. Housing; 5. Ball screw; 6. Screw nut; 7. Screw nut connecting rod; 8. First connecting rod; 9. Second connecting rod. Detailed Implementation

[0024] The technical solution of this utility model will be further described in detail below through specific embodiments and in conjunction with the accompanying drawings. The described embodiments are only some embodiments of this utility model, and not all embodiments.

[0025] Example 1: Refer to Figures 1 to 5 The embodiment disclosed herein can quickly switch between parallel gripping and adaptive gripping modes to meet the gripping needs in different scenarios, and has high practicality and reliability.

[0026] The gripper uses a direct-drive motor 2 as its power source. Its output end is tightly connected to the lead screw fixing flange 3 via bolts, thereby fixing and locking the ball screw 5 to prevent it from rotating during operation and ensuring the stability and accuracy of the transmission. The other end of the lead screw is mounted in the top bearing seat 21 via a deep groove ball bearing 1. The deep groove ball bearing 1 not only effectively supports the lead screw but also allows it to rotate within a certain range, thus providing basic mechanical motion protection for the opening and closing operation of the gripper.

[0027] After the direct drive motor 2 starts, its rotation drives the ball screw 5 to rotate. The screw nut 6 on the ball screw 5 moves up and down linearly under the rotation of the screw. The screw nut 6 is firmly connected to the nut connecting rod 7, which in turn drives the first connecting rod 8 and the second connecting rod 9 to rotate in sequence. The second connecting rod 9 is firmly mounted on the gripper housing 4 by the fixing pin 11 and can rotate freely around the fixing pin 11. This design allows power to be smoothly transmitted to the subsequent connecting rod assembly, driving the third connecting rod 24 and the fifth connecting rod 25 to move, forming a complete and coordinated connecting rod transmission system, providing precise mechanical control for the opening and closing of the gripper.

[0028] One end of the fourth link 23 is fixed to the housing 4 near the direct drive motor 2, while the other end is firmly connected to the fifth link 25, thus constraining and guiding the movement trajectory of the fifth link 25. The gripping finger 12 and the rubber pad 13 are carefully installed on the fifth link 25. The rubber pad 13 is designed to increase friction during the gripping process, preventing the object from slipping during gripping, and also to provide some protection to the surface of the gripped object, avoiding damage.

[0029] Work mode

[0030] Parallel gripping mode: When parallel gripping is required, the conversion pin 26 is securely inserted between the second link 9 and the third link 24. At this time, the second link 9 and the third link 24 are cleverly connected into a whole, and the multi-link mechanism instantly forms a parallelogram structure. With the regular change of the angles between the sides inside the quadrilateral, the two fingers of the gripper can maintain a high degree of parallelism in their opening and closing movements. This design enables the gripper to achieve precise and stable gripping of regular objects in parallel gripping mode, ensuring that the object will not tilt or shake during the gripping process, greatly improving the reliability and accuracy of gripping.

[0031] Adaptive Grip Mode: When dealing with irregularly shaped objects or needing to perform gripping operations in complex environments, the conversion pin 26 is pulled out from between the second link 9 and the third link 24, and the gripper 12 immediately switches to the adaptive gripping state. When the gripper 12 is not in contact with the object being gripped and is in a freely open / closed state, the retaining springs installed on the third link 24 and the fifth link 25 apply a small preload, keeping the gripper 12 parallel in the initial state, preparing for the gripping action. Once the gripper 12 grips an irregular object, its unique adaptive mechanism begins to function. The gripper cleverly overcomes the preload provided by the retaining springs, utilizing the contact and relative movement between the fourth link 23 and the gripper 12 fingers to tightly adhere to the object surface, achieving a stable and secure gripping of irregular objects. This adaptive gripping mode fully demonstrates the flexibility and adaptability of the gripper, enabling it to handle gripping tasks in various complex scenarios and greatly expanding the application range of the gripper.

[0032] This gripper employs advanced direct-drive motor current feedback technology to achieve precise control of the gripping force. During clamping, the direct-drive motor 2 adjusts its output torque in real time based on the current feedback signal, thereby indirectly controlling the gripper's clamping force. This control method cleverly avoids the use of an additional force sensor, which not only simplifies the gripper's structural design and reduces manufacturing costs, but also reduces potential failure points caused by force sensors, thus improving the overall system reliability.

[0033] By adopting direct-drive motor current feedback technology to replace the traditional force sensor, and by optimizing the overall structure design, the purchase cost of the force sensor is eliminated. At the same time, the potential failure risk and maintenance cost caused by the increase in the number of components are reduced, thereby significantly reducing the manufacturing cost of the gripper and improving the cost-effectiveness of the product.

[0034] On the one hand, the use of ball screw transmission effectively reduces backlash during the transmission process, making the grippers run more smoothly during opening and closing, and improving the accuracy and reliability of the transmission. On the other hand, the adaptive gripping mechanism ensures that the grippers automatically adjust the gripping angle and force when gripping irregular objects, achieving a stable gripping effect and avoiding problems such as slippage or damage caused by irregular object shapes or uneven gripping force, greatly improving the stability of gripping.

[0035] The transmission mechanism and elastic element of the gripper are cleverly designed as an internal structure, which effectively avoids the risk of injury to operators caused by exposed parts in traditional grippers, such as pinching or scratching. It also prevents external debris from entering the gripper and interfering with normal operation, thus improving the safety and stability of the gripper in complex working environments.

[0036] By designing a detachable linkage locking pin, the system enables rapid switching between parallel gripping and adaptive gripping modes. This allows the gripper to flexibly adjust its gripping method according to different work requirements, meeting diverse application scenarios and greatly improving the gripper's versatility and practicality, providing users with a more convenient and efficient user experience.

[0037] In summary, the force-controlled adaptive gripper disclosed in this embodiment, with its ingenious structural design, precise control method, and various practical design advantages, has broad application prospects in industrial automation, robot operation, and various fields requiring precise gripping. It is expected to provide an efficient, reliable, and economical gripping solution for the development of related industries.

[0038] Example 2: Refer to Figures 1 to 5 The outer shell 4 is made of high-strength aluminum alloy, which has good rigidity and resistance to deformation. Its internal structure is rationally designed, providing positioning space for the installation of various components. At the same time, the external surface is specially treated, which has the characteristics of corrosion resistance and wear resistance, and can adapt to complex industrial environments.

[0039] The direct-drive motor 2, mounted at the bottom of the housing 4, is the power source for the grippers. Compared to traditional motors driven by transmission devices such as reducers, the direct-drive motor offers higher efficiency, smaller size, and lower noise. It can directly output precise torque and speed to meet the power requirements of the grippers under different working conditions, and possesses excellent dynamic response performance, allowing it to quickly adapt to load changes.

[0040] The ball screw 5, driven by the direct-drive motor 2, is a key component in converting the motor's rotary motion into linear motion. Its screw is made of high-strength alloy steel, undergoing precision machining and heat treatment to ensure high precision and high hardness. The ball screw's ball circulation system is rationally designed to ensure smooth operation and low friction loss during long-term use, thereby improving the lifespan of the grippers and transmission accuracy.

[0041] The lead screw nut connecting rod 7 is fixedly connected to the lead screw nut 6 on the ball screw 5, and is responsible for transmitting the linear motion of the ball screw to the subsequent linkage mechanism. It is made of high-strength alloy steel and precision-machined to ensure high precision and rigidity during transmission. The surface of the connecting rod undergoes a special coating treatment, providing excellent wear resistance and corrosion resistance.

[0042] The links are connected by fixing pins 11, which have high-precision fitting tolerances to ensure tightness of connection and flexibility of rotation between the links. The connecting parts on both sides of the third link 24 are thicker, and the middle has a concave structure. This design ensures the strength of the link while reducing the overall weight and optimizing the motion performance of the gripper. The fourth link 23 is fixed to the outer shell 4 on one side, serving to guide and constrain the movement of the fifth link 25, ensuring the stability and accuracy of the gripper's movement during opening and closing.

[0043] A gripper 12 is fixed above the fifth link 25, and a rubber pad 13 is provided on one side of the gripper 12. The gripper 12 is L-shaped. This L-shaped design allows the gripper to provide a larger contact area and a more stable clamping force when grasping an object. The rubber pad 13 is made of highly elastic, high-friction rubber material, which can increase the friction between the gripper and the object during the clamping process, prevent the object from slipping, and at the same time protect the surface of the object from scratches or damage.

[0044] The switching pin 26 is a crucial component for switching the gripper's operating mode, and it is fixed between the second link 9 and the third link 24. By inserting or removing the switching pin 26, the kinematic characteristics of the linkage mechanism can be altered, thereby enabling rapid switching between parallel gripping and adaptive gripping modes.

[0045] The top of the ball screw 5 is a top bearing housing 21, which houses a deep groove ball bearing 1. The deep groove ball bearing 1 features low friction, high precision, and long service life, effectively supporting the rotational movement of the ball screw 5 and bearing certain axial and radial loads, ensuring the stability and precision of the ball screw during operation.

[0046] Fasteners 22 are provided on the top bearing housing 21 to securely mount the top bearing housing 21 onto the housing 4. The fasteners 22 are made of high-strength bolts and nuts and are designed with anti-loosening measures in mind to ensure that the top bearing housing 21 will not loosen during long-term operation of the gripper, thereby ensuring the normal operation of the ball screw 5.

[0047] The lead screw nut 6 is mounted on the ball screw 5 and is fixedly connected to the lead screw nut connecting rod 7. It adopts a high-precision ball screw pair with a reasonable internal structure design, ensuring smooth ball circulation and achieving high transmission efficiency and precise positioning accuracy.

[0048] In parallel gripping mode, when parallel gripping is required, the conversion pin 26 is inserted between the second link 9 and the third link 24. At this time, the second link 9 and the third link 24 are connected as a whole, and the multi-link mechanism forms a parallelogram structure. As the direct drive motor 2 drives the ball screw 5 to rotate, the screw nut 6 moves linearly along the ball screw 5, and through the screw nut connecting rod 7, it sequentially drives the first link 8, the second link 9, the third link 24, and the fifth link 25 to move. Due to the characteristics of the parallelogram mechanism, the line connecting the two ends of the second link 9 and the third link 24 remains parallel to the fourth link 23, so that the gripper 12 always remains parallel during the opening and closing process. This parallel gripping mode is suitable for gripping regular objects, ensuring that the object will not tilt or shake during the gripping process, thus improving the stability and accuracy of the gripping.

[0049] Adaptive gripping mode

[0050] When dealing with irregularly shaped objects or needing to perform clamping operations in complex environments, the conversion pin 26 is pulled out from between the second link 9 and the third link 24, and the gripper 12 switches to the adaptive gripping state. When the gripper 12 is not in contact with the object being gripped and is in a freely open / closed state, the retaining springs installed in the third link 24 and the fifth link 25 apply a small preload, keeping the gripper 12 parallel in the initial state. Once the gripper 12 grips an irregular object, its unique adaptive mechanism begins to function. Because the preload provided by the retaining springs in the third link 24 and the fifth link 25 is relatively small, the gripper 12 can overcome the force of the retaining springs and, using the relative movement between the fourth link 23 and the gripper 12, tightly adhere to the object surface, achieving a stable and secure gripping of irregular objects. This adaptive gripping mode fully demonstrates the flexibility and adaptability of the gripper, enabling it to handle clamping tasks in various complex scenarios and greatly expanding the application range of the gripper.

[0051] This gripper employs advanced direct-drive motor current feedback technology for precise control of the gripping force. During clamping, the direct-drive motor 2 adjusts its output torque in real time based on the current feedback signal, thereby indirectly controlling the gripper's clamping force. When the gripper contacts the object and begins to apply clamping force, the motor current changes accordingly. By monitoring these current changes, the control system accurately determines the magnitude of the clamping force and adjusts the motor output accordingly, ensuring that the clamping force remains within the set range. This control method cleverly avoids the use of additional force sensors, simplifying the gripper's structural design, reducing manufacturing costs, minimizing potential failure points due to force sensors, and improving the overall system reliability.

[0052] By replacing traditional force sensors with direct-drive motor current feedback technology and optimizing the overall structure, the cost of purchasing force sensors is eliminated. This also reduces potential failure risks and maintenance costs associated with an increased number of components, significantly lowering the manufacturing cost of the gripper and improving its cost-effectiveness. Furthermore, the rational structural design and component selection minimize material consumption and processing difficulty while ensuring performance, further reducing production costs. The first, second, third, fourth, and fifth links are fixed together using fixing pins.

[0053] On the one hand, the use of ball screw transmission effectively reduces backlash during the transmission process, making the grippers run more smoothly during opening and closing, and improving the accuracy and reliability of the transmission. The high precision and low friction characteristics of the ball screw ensure the stability of the grippers during movement, avoiding clamping force fluctuations and positional errors caused by transmission backlash. On the other hand, the adaptive clamping mechanism ensures that the grippers automatically adjust the clamping angle and force when clamping irregular objects, achieving a stable clamping effect and avoiding problems such as slippage or damage caused by irregular object shapes or uneven clamping forces, greatly improving the stability of clamping.

[0054] By designing the transmission mechanism and elastic element of the gripper as a built-in structure, the risks of injury to operators caused by exposed parts in traditional grippers, such as hand pinching or scratches, are effectively avoided. It also prevents external debris from entering the gripper and interfering with normal operation, improving the gripper's safety and stability in complex working environments. Furthermore, the overall structural design of the gripper incorporates measures to prevent parts from loosening and falling off, further enhancing its safety during long-term operation.

[0055] By designing a detachable linkage locking pin, the system enables rapid switching between parallel gripping and adaptive gripping modes. This allows the gripper to flexibly adjust its gripping method according to different work requirements, meeting diverse application scenarios and greatly improving its versatility and practicality. This multi-functionality makes the gripper widely applicable in industrial automated production lines, robot operation, logistics handling, and various fields requiring precise gripping. It can adapt to the requirements of different industries and tasks, providing users with a more convenient and efficient user experience.

[0056] This utility model's force-controlled adaptive gripper combines numerous advantages such as lightweight, high performance, intelligence, versatility, and flexibility, bringing a brand-new solution to fields such as industrial automation and robotics applications. The lightweight design allows the gripper to minimize material usage while ensuring structural strength and durability, reducing both cost and weight. This makes the gripper more flexible and efficient during operation, enabling it to quickly respond to various operational commands and improve work efficiency.

[0057] High performance is reflected in the reliability and superior performance of the gripper. It employs advanced manufacturing processes and high-quality materials, ensuring stable operation even under prolonged, high-intensity working conditions. Simultaneously, the gripper's transmission system is meticulously designed and optimized, enabling precise force and position control to meet the demands of high-precision operations. Its intelligent features make this gripper particularly suitable for intelligent robots. Equipped with advanced sensors and a control system, the gripper can perceive key parameters such as gripping force and position in real time and automatically adjust according to preset algorithms. This intelligent design allows the gripper to grasp and manipulate objects as flexibly as a human hand, greatly enhancing the robot's autonomy and adaptability.

[0058] Versatility is another major advantage of this gripper. Adopting a standardized design concept, the gripper of this invention can be easily integrated with various robots and automation equipment. Whether it's component assembly on an industrial production line, cargo handling in a logistics warehouse, or precision operations in a laboratory, this gripper can handle it all, demonstrating broad applicability. The gripper's design fully considers sensitivity and adaptability. It can quickly switch between different working modes, easily achieving both parallel gripping of regular objects and adaptive gripping of irregular objects. This flexibility allows the gripper to maintain high efficiency in varied working environments, meeting diverse needs in different scenarios.

[0059] With its advantages of lightweight, high performance, intelligence, versatility and flexibility, this new type of force-controlled adaptive gripper will surely play an important role in the future field of industrial automation and robotics, and become a key force in promoting industrial upgrading and technological innovation.

[0060] For those skilled in the art, the present invention is not limited to the details of the above exemplary embodiments, and can be implemented in other specific forms without departing from the spirit or basic characteristics of the present invention.

Claims

1. A force-controlled adaptive gripper, characterized by, The utility model relates to a kind of adaptive gripper, including shell, the bottom of shell is fixed direct drive motor, direct drive motor drives ball screw, ball screw upper connection screw nut connecting rod, screw nut connecting rod is fixed first connecting rod, first connecting rod connects second connecting rod, second connecting rod connects third connecting rod, third connecting rod connects fifth connecting rod, fourth connecting rod one side is fixed on shell, one side is fixed on fifth connecting rod, fifth connecting rod upper fixed clamping jaw.

2. The force-controlled adaptive gripper of claim 1, wherein, Conversion pin is fixed between second connecting rod and third connecting rod.

3. The force-controlled adaptive gripper of claim 2, wherein, When parallel clamping, conversion pin is inserted, and the line connecting the two ends of second connecting rod and third connecting rod is parallel to fourth connecting rod.

4. A force-controlled adaptive gripper according to claim 2 or 3, characterized in that, When adaptive clamping, the spring ring in third connecting rod and fifth connecting rod exerts a small amount of force to maintain the parallelism of clamping jaw, and the clamping jaw overcomes the force of spring ring to make fourth connecting rod and clamping jaw tightly embrace the surface of object.

5. The force-controlled adaptive gripper of claim 1, wherein, First connecting rod, second connecting rod, third connecting rod, fourth connecting rod and fifth connecting rod are fixed by fixed pin.

6. The force-controllable adaptive gripper of claim 1 or 5, wherein, The connecting part on both sides of third connecting rod is relatively thick, and the middle part is concave structure.

7. The force-controllable adaptive gripper of claim 1 or 5, wherein, The top of ball screw is top bearing seat, and deep groove ball bearing is arranged in top bearing seat.

8. The force-controlled adaptive gripper of claim 7, wherein, Fastener is arranged on top bearing seat.

9. The force-controllable adaptive gripper of claim 1 or 8, wherein, One side of clamping jaw is provided with rubber pad, and the whole clamping jaw is L-shaped.

10. The force-controlled adaptive gripper of claim 9, wherein, Screw nut is arranged between screw nut connecting rod and ball screw to fix them.

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