A robot end effector capable of changing different finger types

Abstract

The utility model discloses a kind of robot end effector of different finger type replaceable, including drive motor being connected by quick installation fixing piece with robot arm, gripper is connected with drive motor by execution mechanism fixed component;The execution mechanism fixed component includes fixed pedestal and crank connecting rod mechanism installed on drive motor;The quick installation fixing piece, including motor end fixed part being fixedly connected with drive motor stator end, external fixed part is connected with motor end fixed part, and installation hole that robot external interface is adapted is equipped on external fixed part;The crank connecting rod mechanism includes motor crank connecting piece, crank, connecting rod, slide rail, slider and gripper fixed base.The utility model greatly reduces the assembly difficulty when end effector and external interface assembly, assembly structure simplifies, overall space layout is compressed, and end effector occupies space reduction when working.

Description

Technical Field

[0001] This utility model relates to the field of robotics, specifically to a robot end effector with interchangeable finger types. Background Technology

[0002] Robots have been widely used in various fields such as industrial production, aerospace, and logistics. As an important component of robots, the end effector has a variety of structural forms. Taking a common material sorting robot as an example, its end effector is usually a gripper, used to pick up and pack different materials. This type of gripper is usually driven by electric or pneumatic means, such as electric grippers, pneumatic grippers, or suction cups.

[0003] Among the various types of end effectors listed above, electric grippers are more complex in overall structure because they must have a drive device and a transmission structure; pneumatic grippers, on the other hand, usually have a larger overall size and occupy a lot of space because they need to arrange air lines and pipes, which is not conducive to the miniaturization of robots; and in order to ensure the normal use of pneumatic grippers, compressed air sources or vacuum pumps need to be arranged at the same time, which will increase the cost of use and space occupation.

[0004] In existing logistics sorting technology solutions, when faced with materials of different sizes and shapes (such as boxes, bags, and irregular shapes) and densely packed materials with very small gaps, there is a long-standing problem that has not been effectively solved: the contradiction between the specialization of end effectors and the diversity of materials.

[0005] Currently, the mainstream solution is to configure various specialized grippers (such as parallel two-finger grippers, vacuum suction cups, multi-finger dexterous hands, etc.) for human-robot collaboration. When the production line needs to switch to sorting different materials, the robot operation must be paused, and the grippers must be replaced and recalibrated manually or by an auxiliary gripper changing device. Summary of the Invention

[0006] To address the shortcomings of the existing technology, this utility model aims to provide a robot end effector with interchangeable finger types, which can quickly adapt to various material conditions by changing different finger types.

[0007] To achieve the above objectives, the technical solution of this utility model is as follows: A robot end effector with interchangeable finger types includes a drive motor connected to a robot arm via a quick-install fastener, and a gripper connected to the drive motor via an actuator fixing component; The quick-install fastener includes a motor end fastener that is fixedly connected to the stator end of the drive motor, and an external fastener that is connected to the motor end fastener. The external fastener is provided with mounting holes that are compatible with the robot's external interface. The actuator fixing assembly includes a fixed base mounted on the drive motor and a crank-connecting rod mechanism; the crank-connecting rod mechanism includes a motor crank connector, a crank, a connecting rod, a slide rail, a slider, and a gripper fixing base. The slide rail is mounted on a fixed base, the slider is embedded in the slide rail, and the clamping base is connected to the slider; one end of the connecting rod is connected to the slider, and the other end is connected to the crank; the crank is connected to the rotor end of the drive motor through the motor crank connector.

[0008] The motor end fixing component has an external threaded hole on its side wall, and the external fixing component is connected to the motor end fixing component through the external threaded hole; the external fixing component is connected to the robot arm through the mounting hole. The drive motor is equipped with a force sensor and a position encoder, and the fixed base is fixedly connected to the drive motor by bolts.

[0009] The crank includes a crank disc with two crank connecting ends connected to the connecting rod; the crank disc has multiple connecting holes, and the motor crank connector is connected to the crank through the connecting holes, and the motor crank connector is connected to the threaded hole at the end of the motor rotor by bolts.

[0010] The crank connecting end is connected to one end of the connecting rod via bearing bolts and a flange, and the other end of the connecting rod is connected to the clamp fixing base via bearing bolts and a flange.

[0011] The gripper fixing base is connected to the slider by bolts, and the gripper is connected to the gripper fixing base by bolts.

[0012] The grippers include thin-plate grippers adapted to handle material boxes and parallel grippers suitable for general scenarios.

[0013] In the crank-connecting rod mechanism, there is a geometric constraint relationship between the connecting rod and the crank, namely the connecting rod angle and the crank angle. in, The crank angle is the angle between the crank and the fixed base. The connecting rod angle is the angle between the connecting rod and the horizontal line. R is the length of the connecting rod.

[0014] The fixed base has a protruding structure that is on the same horizontal line as the crank-connecting rod mechanism to limit the crank's rotation range.

[0015] A layer of friction material is coated or adhered to the contact surface between the gripper and the target material.

[0016] The gripper is connected to the gripper fixing base by screws; When changing to different finger types of grippers, remove the screws on the gripper fixing base to remove the gripper, and then use the screws to fix the gripper to be replaced on the gripper fixing base.

[0017] Compared with existing solutions, this utility model has the following advantages: This utility model is an end effector mounted on a robot arm structure or mechanical arm. It connects to an external motor end fixing component via bolts. The motor end fixing component can be connected and fixed to the external fixing component using bolts through pre-drilled holes on the side. Other components can be connected to the motor end fixing component through the cooperation between the motor end fixing component and the external fixing component, and screws can be passed through the pre-drilled holes of the external fixing component. This achieves overall fixation of the end effector, greatly reducing the assembly difficulty when assembling the end effector with external interfaces. The assembly structure is simplified, the overall space layout is compressed, and the space occupied by the end effector during operation is reduced.

[0018] The end effector of this invention increases friction by incorporating high-friction rubber pads on the gripper surface, effectively overcoming the slippage problem that easily occurs with smooth materials and ensuring reliable gripping. For soft or easily deformable materials, the distributed compressive stress and larger contact area provided by the high-friction rubber pads enable a more compliant and stable enveloping grip, avoiding damage caused by localized stress concentration. This design allows the gripper to achieve the required gripping force with less positive pressure, thereby reducing the risk of damage to force-sensitive or fragile materials during gripping. Therefore, the introduction of this high-friction contact surface greatly enhances the adaptability and operational safety of the end effector in complex material mixing scenarios. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of this utility model; Figure 2 This is a schematic diagram of the quick-installation fastener structure of this utility model; Figure 3 This is a schematic diagram of the crank-connecting rod component structure of this utility model; Figure 4 This is a schematic diagram of the gripper of this utility model; Figure 5 This is a schematic diagram of the thin-film gripper of this utility model.

[0020] Among them, 1 is the gripper, 2 is the fixed base, 3 is the drive motor, 4 is the slide rail, 5 is the crank, 6 is the connecting rod, 7 is the motor end fixing part, 8 is the external fixing part, 9 is the gripper fixing base, 10 is the slider, 11 is the bearing bolt, 12 is the motor crank connecting part, and 13 is the thin-plate gripper. Detailed Implementation

[0021] See Figures 1-5 A robot end effector with interchangeable finger types includes a drive motor connected to a robot arm via a quick-install fastener, and a gripper connected to the drive motor via an actuator fixing component. The quick-install fastener includes a motor end fastener that is fixedly connected to the stator end of the drive motor, and an external fastener that is connected to the motor end fastener. The external fastener is provided with mounting holes that are compatible with the robot's external interface. The actuator fixing assembly includes a fixed base mounted on the drive motor and a crank-connecting rod mechanism; the crank-connecting rod mechanism includes a motor crank connector, a crank, a connecting rod, a slide rail, a slider, and a gripper fixing base. The slide rail is mounted on a fixed base, the slider is embedded in the slide rail, and the clamping base is connected to the slider; one end of the connecting rod is connected to the slider, and the other end is connected to the crank; the crank is connected to the rotor end of the drive motor through the motor crank connector.

[0022] See Figure 2 The motor end fixing component has an external threaded hole on its side wall, and the external fixing component is connected to the motor end fixing component through the external threaded hole; the external fixing component is connected to the robot arm through the mounting hole. The drive motor is equipped with a force sensor and a position encoder, and the fixed base is fixedly connected to the drive motor by bolts.

[0023] Specifically, the drive motor is a high-torque brushless DC motor with a single-stage planetary reduction gear. It integrates a force sensor and a position encoder, realizing the force sensing and force feedback functions of the end effector. The force feedback function uses the torque current value of the gripper motor of the slave robot under load as a direct sensing signal of the interactive force, which is wirelessly transmitted to the master controller. The torque constant is used to convert it into a torque to resist the operator, improving the force control performance of the end effector. The position encoder is responsible for detecting the position, rotation speed and direction of the motor shaft in real time and accurately. By continuously feeding back this key information to the controller, it enables the system to achieve various precise operations from simple speed adjustment to complex trajectory tracking.

[0024] The encoder's function is primarily reflected in three aspects: First, precise positioning, directly informing the controller of the absolute or relative angle of the motor shaft; second, accurate speed measurement, where the system calculates the change in position pulses per unit time to determine the motor's real-time speed; and third, direction determination, where the system accurately identifies the motor's forward or reverse rotation by interpreting the phase relationship between the two signals. The ultimate goal of all this feedback data is to construct a closed-loop control system—the controller compares the error between the "command target" and the "actual result" fed back by the encoder, and dynamically adjusts the output to eliminate this error, thus improving the adaptability of the end effector to various materials.

[0025] See Figure 3 The crank includes a crank disc with two crank connecting ends connected to the connecting rod; the crank disc has multiple connecting holes, and the motor crank connector is connected to the crank through the connecting holes, and the motor crank connector is connected to the threaded hole at the end of the motor rotor by bolts.

[0026] Specifically, the crank connecting end is connected to one end of the connecting rod via bearing bolts and a flange, and the other end of the connecting rod is connected to the clamp fixing base via bearing bolts and a flange.

[0027] The gripper fixing base is connected to the slider by bolts, and the gripper is connected to the gripper fixing base by bolts.

[0028] Specific implementation examples are given below.

[0029] A robot end effector with interchangeable finger types includes a quick-mount fixture for connecting to a robot arm, a drive motor, an actuator fixing assembly, and interchangeable grippers. The grippers include grippers adapted to handle material boxes and parallel grippers suitable for general scenarios; The actuator fixing assembly includes a fixing base directly mounted on the drive motor and a crank-connecting rod mechanism; The quick-install fastener includes a motor end fastener 7 that is directly fixed to the stator end of the motor and an external fastener 8. The two are fixedly connected through threaded holes on the side wall of the motor end fastener 7. The external fastener 8 can be connected and fixed to an external interface through reserved holes. The other components of the end effector mentioned in this utility model can be connected to the motor end fastener through the cooperation between the motor end fastener 7 and the external fastener 8, and screws are used to pass through the reserved holes of the external fastener, thereby achieving the overall fixation of the end effector.

[0030] The crank-connecting rod mechanism includes a motor-crank connector, a crank, a connecting rod, a slide rail, a slider, and a clamping base. The slide rail is directly connected to the fixed base. The crank and the crank-motor connector are positioned relative to each other by pre-drilled holes evenly distributed around a circumference of the same diameter, and are directly connected to the threaded holes at the motor rotor end by bolts. The crank is connected to the connecting rod on both sides via bearing bolts and a flange structure. The other end of the connecting rod uses the same design to connect to the clamping base.

[0031] The gripper fixing base is connected to the slider by bolts. The various grippers involved in this utility model can be directly connected to the gripper fixing base by bolts, so as to realize quick gripper replacement for various materials.

[0032] It should be noted that the crank-connecting rod mechanism involved in this utility model is actually used for sorting different materials. Considering the diverse characteristics of the materials being sorted (such as size and weight), and for practical needs, this crank-connecting rod mechanism needs to ensure sufficient force transmission efficiency during the connecting rod stroke. Therefore, this utility model proposes a basic relationship between output force, input torque, and angle: in, F out For the output force, τ in The input torque is R, and the link length is R. This refers to the connecting rod angle, which is the angle between the crank and the fixed base. The crank angle is the angle between the connecting rod and the horizontal line. Linkage angle With crank angle Geometric constraints: As can be seen from the above formula, the output force is strongly dependent on the connecting rod angle. With crank angle ; The force amplification of the mechanism varies at different stroke points, especially when the crank is near the connecting rod dead center (0). 0 Or 180 0 When the crank is perpendicular to the connecting rod, the connecting rod exhibits the characteristic of being unable to start automatically; however, when the crank is perpendicular to the connecting rod, the force utilization rate is the highest, and most of the input torque is used to generate an effective torque to drive the rocker arm to rotate, resulting in the greatest mechanical benefit.

[0033] Because the fixed base adopts an integrated design, the overall structural strength of the fixture is increased, while assembly errors are effectively reduced. Therefore, during the machining of the fixed base, a protruding structure (as a limit block) at the same horizontal line as the crank mechanism is retained, which limits the crank rotation range. This ensures that the connecting rod mechanism is symmetrical in posture at the maximum and minimum stroke points and always remains within the stroke range with high force transmission efficiency, improving the working efficiency of the fixture and making the clamping force feedback scheme of the fixture easier to implement.

[0034] The introduction of the limiting design on the fixed base allows the connecting rod in the crank-connecting rod structure to move from its maximum stroke to its minimum stroke. The motor, as the power and control core, has its output shaft rigidly connected to the crank via a reducer. When the motor receives a command to start rotating from its initial position, the crank, fixed to the motor shaft, rotates at a constant or controlled speed. Simultaneously, the limitation imposed by the limiting structure on the crank's rotational range allows for a change in posture from 0° to 180°. This enables the end effector designed in this invention to better adapt to the force feedback mechanism, allowing the force feedback mechanism to achieve a one-to-one force mapping relationship using a proportionally proportioned crank-connecting rod mechanism.

[0035] In the end-efficiency actuators for material sorting scenarios described in this invention, the highly diverse nature of materials to be processed in industrial settings often results in significant differences in their physical form and surface properties. These differences are not only reflected in the size, weight, and shape of the materials, but more importantly, in key physical properties such as surface roughness, material hardness, and coefficient of friction. This invention integrates a layer of specially formulated friction material, typically a polyurethane elastomer pad, into the direct contact surfaces of various replaceable grippers and target materials. The surface of this material can be further processed with micro-textured structures or irregular patterns. This design aims to significantly increase the static and dynamic coefficients of friction of the contact surfaces, thereby enhancing the maximum static friction and gripping adhesion of the grippers to the materials.

[0036] When changing to different finger types of grippers, remove the screws or bolts on the gripper fixing base to remove the gripper, and then use screws or bolts to fix the gripper to be replaced on the gripper fixing base.

[0037] The robot end effector proposed in this utility model, which can be interchanged with different finger types, is suitable for small-batch, multi-variety mixed production lines. It enables a single robot to autonomously switch between two-finger force-controlled grippers, adaptive multi-finger grippers, or vacuum suction cup arrays within seconds according to process requirements, so as to complete heterogeneous tasks from precision electronic component assembly to large sheet metal part handling with the optimal strategy.

[0038] In smart logistics hubs, it drives "goods-to-person" robots to dynamically adapt to the physical characteristics of massive SKUs. By integrating visual and force perception, it seamlessly switches from grasping rigid packaging boxes to handling unstructured soft-packaged items, achieving a paradigm shift in sorting efficiency. From agricultural robots selectively harvesting fruits and vegetables based on tactile feedback to surgical robots performing aseptic and rapid replacement of high-frequency instruments, this system, through its excellent task adaptability and interface standardization, is continuously expanding the operational boundaries of robots in unstructured environments, laying the foundation for the perception and execution of the next generation of intelligent robots.

[0039] The embodiments given above are preferred examples of implementing this utility model, and this utility model is not limited to the above embodiments. Any non-essential additions or substitutions made by those skilled in the art based on the technical features of the technical solution of this utility model shall fall within the protection scope of this utility model.

Claims

1. A robot end effector with interchangeable finger types, characterized in that, This includes a drive motor that is connected to the robot arm via a quick-install fastener, and a gripper that is connected to the drive motor via an actuator fixing assembly; The quick-install fastener includes a motor end fastener that is fixedly connected to the stator end of the drive motor, and an external fastener that is connected to the motor end fastener. The external fastener is provided with mounting holes that are compatible with the robot's external interface. The actuator fixing assembly includes a fixed base mounted on the drive motor and a crank-connecting rod mechanism; the crank-connecting rod mechanism includes a motor crank connector, a crank, a connecting rod, a slide rail, a slider, and a gripper fixing base. The slide rail is mounted on a fixed base, the slider is embedded in the slide rail, and the clamping base is connected to the slider; one end of the connecting rod is connected to the slider, and the other end is connected to the crank; the crank is connected to the rotor end of the drive motor through the motor crank connector.

2. The robot end effector with interchangeable finger types as described in claim 1, characterized in that, The motor end fixing component has an external threaded hole on its side wall, and the external fixing component is connected to the motor end fixing component through the external threaded hole; the external fixing component is connected to the robot arm through the mounting hole. The drive motor is equipped with a force sensor and a position encoder, and the fixed base is fixedly connected to the drive motor by bolts.

3. The robot end effector with interchangeable finger types as described in claim 1, characterized in that, The crank includes a crank disc with two crank connecting ends connected to the connecting rod; the crank disc has multiple connecting holes, and the motor crank connector is connected to the crank through the connecting holes, and the motor crank connector is connected to the threaded hole at the end of the motor rotor by bolts.

4. The robot end effector with interchangeable finger types as described in claim 3, characterized in that, The crank connecting end is connected to one end of the connecting rod via bearing bolts and a flange, and the other end of the connecting rod is connected to the clamp fixing base via bearing bolts and a flange.

5. The robot end effector with interchangeable finger types as described in claim 1, characterized in that, The gripper fixing base is connected to the slider by bolts, and the gripper is connected to the gripper fixing base by bolts.

6. The robot end effector with interchangeable finger types as described in claim 1, characterized in that, The grippers include thin-plate grippers adapted to handle material boxes and parallel grippers.

7. The robot end effector with interchangeable finger types as described in claim 1, characterized in that, In the crank-connecting rod mechanism, there is a geometric constraint relationship between the connecting rod and the crank, namely the connecting rod angle and the crank angle. ； in, The crank angle is the angle between the crank and the fixed base. The connecting rod angle is the angle between the connecting rod and the horizontal line. R is the length of the link.

8. The robot end effector with interchangeable finger types as described in claim 1 or 7, characterized in that, The fixed base has a protruding structure that is at the same horizontal level as the crank-connecting rod mechanism to limit the crank's rotation range.

9. The robot end effector with interchangeable finger types as described in claim 1, characterized in that, A layer of friction material is coated or adhered to the contact surface between the gripper and the target material; the surface of the friction material is provided with a micro-texture structure or irregular pattern.

10. The robot end effector with interchangeable finger types as described in claim 1, characterized in that, The gripper is connected to the gripper fixing base by screws or bolts; When changing to different finger types of grippers, remove the screws or bolts on the gripper fixing base to remove the gripper, and then use screws or bolts to fix the gripper to be replaced on the gripper fixing base.

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