A flexible gripping device for a multi-jaw assembly

Abstract

The utility model discloses a flexible grabbing device of multiple gripper subassembly, include: connecting plate, be provided with the installation interface for with industrial robot end flange connection on connecting plate, at least two gripper units, fixedly set up on the same installation surface of connecting plate, at least two position inductors, fixedly set up on connecting plate, and respectively with each gripper unit's position corresponds, wherein, each gripper unit all includes an independent drive cylinder and a clamping assembly directly driven by the drive cylinder, each position inductor is connected with corresponding drive cylinder signal, is used for independently triggering corresponding gripper unit to execute the grabbing action according to the workpiece position information detected, the utility model discloses through the integration multiple groups independent controllable gripper subassembly and corresponding inductor, realizes the automatic identification and adaptive grabbing of different workpieces, promotes the flexible level and the degree of automation of production line, and provides stable, accurate workpiece positioning for subsequent high-precision visual inspection.

Description

Technical Field

[0001] This utility model relates to the field of automated manufacturing and material handling equipment technology, specifically to a flexible gripping device for use on industrial production lines that can automatically identify and adapt to gripping various workpieces of different specifications. Background Technology

[0002] In modern manufacturing, especially in the production of automotive parts, online inspection of welding quality (such as whether there are any missing welds in weld points, nuts, and studs, and the quality of weld seams) is a crucial step in ensuring product qualification rates. Traditional inspection methods typically employ a model of "mechanical positioning + manual sampling" or "dedicated inspection tools + single-function automated equipment".

[0003] Currently, the typical process for achieving the aforementioned automated inspection is as follows: the workpiece is conveyed to a designated position via a conveyor belt, grasped by a robot, and then moved to a vision inspection station for photographic analysis. However, the traditional grasping fixture, which is the core execution end of this process, has significant limitations: (1) Most gripping fixtures (or grippers) are designed for a single product and have a fixed clamping mechanism. When the production line needs to switch between different types of workpieces (such as side panels and door panels of A / B / C models), the machine must be stopped and the grippers replaced or significantly adjusted, resulting in low equipment utilization, high changeover costs, and serious loss of production cycle time, which cannot meet the needs of modern flexible manufacturing of "small batch and multiple varieties".

[0004] (2) Traditional grippers only have simple gripping and placement functions and do not have the ability to automatically identify workpiece types. In mixed-flow production lines, it is usually necessary to set up additional and complex sensor arrays (such as RFID, multiple photoelectric sensors) upstream or rely on manual visual inspection to identify the workpiece type, and then feed the signal back to the robot control system to call different gripping programs. This "identification-communication-decision-execution" link has many delays and is complex, which can easily become a reliability bottleneck in the automation process.

[0005] (3) For some workpieces that require subsequent high-precision visual inspection, the positioning accuracy and repeatability during the gripping process are crucial. When gripping workpieces with different structures, traditional general-purpose grippers or simple fixtures may cause micro-displacement or vibration of the workpiece during transfer or rotation due to imperfect gripping points or unstable contact. This pose error will be directly transmitted to the vision system, causing image blurring and feature shift, ultimately leading to false detection or missed detection, which cannot meet the stringent requirements of high-precision online inspection. Utility Model Content

[0006] To address the shortcomings of the aforementioned background technology, the purpose of this utility model is to provide a flexible gripping device with a multi-claw assembly. This gripping device, through its unique mechanical structure, aims to achieve automatic identification and selective, precise gripping of different workpieces on an assembly line, transferring and stably maintaining the workpieces at the visual inspection station with extremely high repeatability. This improves the flexibility, automation, and reliability of the gripping process, meeting the needs of mixed-flow production, and providing stable and accurate workpiece positioning for subsequent high-precision visual inspection, thereby enhancing the overall efficiency and reliability of the production system.

[0007] To achieve the above objectives, the present invention provides the following technical solution: A flexible gripping device with a multi-gripper assembly, comprising: A connecting plate, wherein the connecting plate is provided with an installation interface for connecting to the end flange of an industrial robot; At least two gripper units are fixedly mounted on the same mounting surface of the connecting plate; At least two position sensors are fixedly mounted on the connecting plate and correspond to the positions of each of the gripper units; Each of the gripper units includes an independent drive cylinder and a gripping assembly directly driven by the drive cylinder. Each of the position sensors is connected to the corresponding drive cylinder signal, and is used to independently trigger the corresponding gripper unit to perform a gripping action based on the detected workpiece position information.

[0008] Furthermore, at least two gripper units are linearly arranged along the length or width direction of the connecting plate.

[0009] Furthermore, the clamping assembly includes a connecting arm connected to the piston rod of the drive cylinder, and a gripper head detachably mounted at the end of the connecting arm. By replacing the gripper head with different shapes or materials, it can further adapt to the clamping requirements of different workpieces.

[0010] Furthermore, it also includes a sensor bracket, through which the position sensor is fixedly mounted on the side of the connecting plate.

[0011] Furthermore, the sensor bracket is an L-shaped sheet metal part, which has a simple structure and is easy to process and install.

[0012] Furthermore, the position sensor is one of a photoelectric sensor, a proximity switch, or a fiber optic sensor, which can be selected according to the workpiece material and the detection environment.

[0013] Furthermore, the connecting plate is provided with weight-reducing holes, which reduces the weight of the overall device while ensuring structural strength, and helps to improve the movement speed and accuracy of the robot end effector.

[0014] The beneficial effects of this utility model are: This invention integrates multiple independently controlled gripper assemblies with corresponding recognition sensors into a single unit, enabling automatic identification of workpieces arriving on the production line and driving the corresponding gripper assemblies for gripping. This achieves automatic adaptive gripping of multiple products with a single gripper, improving the flexibility of the production line and significantly reducing equipment downtime and tooling change time due to product changes. It is suitable for mixed-flow production lines with small batches and multiple product types. The invention features dedicated gripper head designs for different workpieces, combined with detachable connections, ensuring that each workpiece can be gripped in the most suitable and stable manner. This guarantees the positional stability and high repeatability of the workpiece during gripping and transfer, providing a reliable foundation for subsequent processes (such as assembly and inspection). The integration of recognition sensors (position sensors) and actuators (gripper assemblies) onto the same connecting plate, and direct control via corresponding signal links, eliminates complex external decision-making and communication processes. The short signal path and fast control response contribute to improved production cycle time.

[0015] This utility model design integrates multiple gripping functions into a single device, with a compact structure. It eliminates the need for multiple independent gripping stations for different workpieces or complex gripper replacements, greatly saving production line layout space and simplifying equipment structure. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of a flexible gripping device with a multi-claw assembly according to the present invention; Figure 2 This is a schematic diagram of the flexible gripping device in the preferred implementation scheme; Figure 3 This is a schematic diagram of the flexible gripping device from another angle in the preferred embodiment; Figure 4 This is a schematic diagram of the first gripper unit grasping the workpiece in the preferred embodiment. Figure 5 This is a schematic diagram of the second gripper unit grasping the workpiece in the preferred embodiment. Figure 6 This is a schematic diagram of the third gripper unit grasping the workpiece in the preferred embodiment. The components in the attached diagram are labeled as follows: 1. Connecting plate; 11. Mounting interface; 12. Weight reduction hole; 2. First gripper unit; 21. First drive cylinder; 22. First connecting arm; 23. First gripper head; 3. Second gripper unit; 31. Second drive cylinder; 32. Second connecting arm; 33. Second gripper head; 331. Anti-slip structure; 4. First position sensor; 5. Second position sensor; 6. Sensor bracket; 7. Third gripper unit; 8. Workpiece A; 9. Workpiece B; 10. Workpiece C. Detailed Implementation

[0017] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby making a clearer and more definite definition of the scope of protection of the present invention.

[0018] Example: This embodiment describes the structure of a flexible gripping device with a multi-claw assembly.

[0019] refer to Figures 1 to 6 This embodiment provides a flexible gripping device with a multi-claw assembly, specifically applied to an automotive parts production line, for identifying and gripping workpieces of different models, and providing stable and accurate workpiece positioning for subsequent high-precision visual inspection.

[0020] The flexible gripping device mainly includes: a connecting plate 1, at least two gripper units, at least two position sensors, and corresponding sensor brackets 6.

[0021] like Figure 1-3 As shown, the connecting plate 1 is generally rectangular in shape and can be made of aluminum alloy sheet. A standard robot flange mounting interface 11 is located at the center of its top. This interface is a standard robot flange interface, and the entire gripper can be securely mounted to the end flange of a six-axis industrial robot (not shown in the figure) using high-strength bolts, allowing the entire gripping device to move with the robot. To reduce overall weight and robot load, the connecting plate 1 is machined with multiple regularly arranged weight-reduction holes 12. This maximizes weight reduction while maintaining structural strength, which is beneficial for improving the robot's agility and energy efficiency. The bottom plane of the connecting plate 1 serves as the main mounting surface.

[0022] The gripping device is securely connected to the end flange of the six-axis industrial robot via mounting interface 6, serving as a flexible gripping terminal for the robot on the automated production line.

[0023] In a preferred embodiment, the two gripper units, including a first gripper unit 2 and a second gripper unit 3, are bolted side-by-side to the same mounting surface on the bottom of the connecting plate 1 and are linearly arranged along the length of the connecting plate 1. To accommodate different types of workpieces and ensure stable clamping, each gripper unit has an independent structure and control system.

[0024] Specifically, such as Figure 2 , 4 As shown, the first gripper unit 2 includes a first drive cylinder 21 and a first gripping assembly directly driven by the cylinder. The first drive cylinder 21 is preferably a double-acting compact cylinder, its cylinder body being directly fixed to the connecting plate 1 via a mounting base. The first gripping assembly includes a pair of opposing first connecting arms 22, one end of which is connected to the piston rods at both ends of the first drive cylinder 21 via threads or quick-connect couplings, and the other end is detachably fitted with a pair of first gripper heads 23 via screws. Figure 4 As shown, in the preferred embodiment, the clamping surface of the first gripper head 23 is designed as a smooth plane to accommodate workpieces with high surface precision requirements and that are not easily scratched, such as workpiece A. In the preferred embodiment, the first gripper head 23 is designed as an L-shape and mounted facing each other on the first connecting arm 22. The smooth clamping surface of the first gripper head 23 contacts the workpiece and firmly clamps it. The first gripper head can be replaced according to the needs of gripping the workpiece. Since the first connecting arm and the first gripper head are installed in a detachable manner, the convenience of replacement and maintenance are improved.

[0025] The second gripper unit 3 is similar in structure and principle to the first gripper unit 2, also including a second drive cylinder 31 and a second clamping assembly. For example... Figure 2 , 5 As shown, the second clamping assembly includes a pair of second connecting arms 32 and a pair of detachable second gripper heads 33. The difference lies in that, to accommodate a different type of workpiece—such as workpiece B—which is larger in size, requires greater clamping force, and has a more complex structure, an anti-slip structure 331 is designed on the clamping surface of the second gripper heads 33 to improve the gripping force and the stability of workpiece clamping. This anti-slip structure can be formed by anti-slip teeth or by embedding a flexible anti-slip material such as polyurethane. A preferred embodiment shows a workpiece B being clamped, such as… Figure 5 As shown, in this preferred embodiment, the second gripper head 31 is mounted on the second connecting arm 32. A non-slip structure formed by several grooves is provided on the surface of the second gripper head 31 that contacts the workpiece B. The edge of the workpiece B is confined within the grooves and tightly gripped by the second gripper head. This second gripper head is replaceable, and the non-slip structure can be adjusted according to the requirements of the type of workpiece being gripped.

[0026] Correspondingly, in the preferred embodiment, such as Figure 2 and Figure 3 As shown, the position sensor includes a first position sensor 4 and a second position sensor 5, which are fixedly mounted on the side of the connecting plate 1 via sensor brackets 6 made of L-shaped sheet metal. The detection beam of the first position sensor 4 is directed towards the gripping area directly below the first gripper unit 2, while the detection beam of the second position sensor 5 is directed towards the gripping area directly below the second gripper unit 3, thus achieving a one-to-one correspondence between the sensor and the gripper unit. The output signal lines of the two sensors 4 are respectively connected to the control system and are connected one-to-one with the solenoid valves of the cylinders 2 that control the first and second gripper assemblies, forming independent control loops. The position sensor can be selected from photoelectric sensors, proximity switches, or fiber optic sensors. In this embodiment, a through-beam photoelectric sensor is selected as the position sensor, which has the characteristics of high detection accuracy and strong anti-interference ability. Of course, in other embodiments, a proximity switch with adjustable sensing distance or an oil-resistant fiber optic sensor can also be selected according to the workpiece material (metal or non-metal).

[0027] In a preferred embodiment, the gripper unit further includes a third gripper unit 7, such as... Figure 3 , 6 As shown, the third gripper unit 7 is fixedly mounted on the other side of the connecting plate 1, and is not on the same plane as the first gripper unit and the second gripper unit. Similar to the first gripper unit 2, the third gripper unit 7 also includes a drive cylinder and a gripping assembly driven by the drive cylinder, as well as a position sensor connected to the drive cylinder via a corresponding signal. The position sensor of the third gripper unit 7 is fixedly mounted on the connecting plate 1 via a sensor bracket, and is mounted on the same plane as the third gripper unit. Figure 6 As shown, the third gripper unit can grip another workpiece C. By rationally integrating multiple gripper units on the connecting plate at the robot's end effector, the robot can grasp various types of workpieces, greatly improving the flexible gripping capability of the gripping device.

[0028] This invention integrates multiple independent gripper units and corresponding position sensors on a connecting plate. The device can automatically select and trigger the corresponding gripper to grip different workpieces flowing on the conveyor line, realizing "one machine for multiple uses". It significantly improves the equipment's adaptability to multi-variety and small-batch production modes and has a highly flexible gripping capability.

[0029] Working process and control logic: The control valves of the first position sensor 4, the second position sensor 5, the first drive cylinder 21, and the second drive cylinder 31 are all electrically connected to an external control system (such as a programmable logic controller (PLC), not shown in the figure), forming a signal connection relationship. The PLC also communicates with the host robot control system.

[0030] Standby and Detection: The gripping device moves to the pick-up position above the assembly line under the robot's drive. When the assembly line, such as the conveyor belt (not shown in the figure), transports workpiece A to the preset gripping position, workpiece A enters and blocks the light path of the sensor 4 corresponding to the first gripper assembly. The first position sensor 4 detects the workpiece and generates a high-level signal, which is transmitted to the PLC. At this time, the second position sensor 5 does not detect a signal.

[0031] Selective Triggering and Grasping: After receiving a signal only from the first position sensor 4, the PLC, according to a preset program, sends an action command only to the solenoid valve controlling the first drive cylinder 21. The piston rod of the first drive cylinder 21 extends, driving a pair of first gripper heads 23 to move towards each other, thereby clamping the type A workpiece. The magnetic switch (or position sensor) on the cylinder feeds back the clamping completion signal to the PLC. In actual use on the production line, after the workpiece is in place, an industrial camera mounted on another robot or fixed bracket takes multi-angle pictures of workpiece A and compares the images with preset standard images to complete the inspection of welding quality and other items.

[0032] Handling and placement: The PLC transmits the successful gripping signal to the robot control system, and the robot then moves the gripping device and workpiece to the target station. The first drive cylinder 21 reverses its action to release the workpiece.

[0033] Adapting to another workpiece: When a type B workpiece moves to the pick-up position and is detected individually by the second position sensor 5, the sensor 4 corresponding to the second gripper assembly is triggered to automatically respond and execute a gripping action. The PLC will only trigger the second drive cylinder 31 to act, and the second gripper unit 3 will complete the gripping of the type B workpiece. If, due to a malfunction, both types of workpieces unexpectedly appear at the pick-up position simultaneously, the PLC can be preset to alarm or processed according to priority (such as triggering only the first gripper unit) to prevent malfunctions. The entire process seamlessly switches between different workpieces, achieving automatic identification and flexible gripping, significantly improving the adaptability and efficiency of the automated production line.

[0034] This invention integrates multiple sets of independently controllable gripper components and corresponding sensors to achieve automatic identification and adaptive gripping of different workpieces, reducing manual operation and improving the flexibility and automation of the production line. It provides extremely high repeatability for the robot to transport the workpiece to the visual inspection station and take multi-angle photos, fundamentally ensuring the reliability of the inspection results.

[0035] Example 2 In another embodiment, to accommodate a wider variety of workpieces, three or more gripper units and a corresponding number of position sensors can be provided on the connecting plate 1. The gripper units can be arranged linearly or distributed in a two-dimensional array according to the workpiece layout. The gripper head of each gripper unit can be customized according to the shape of its corresponding workpiece, such as a V-shaped gripper, an arc-shaped gripper, or a pneumatic suction cup, etc., and is detachably connected to the connecting arm, realizing modularization and rapid changeover of the gripping function.

[0036] It should be noted that: In the above embodiments, the driving cylinder is only one example of the driving source. Provided that the response speed and force requirements are met, it can also be replaced by linear drive components such as electric push rods and linear motors.

[0037] The implementation of control logic is not limited to PLC; it can also be achieved by robot controllers directly processing sensor signals and controlling cylinder movements.

[0038] The term "detachable installation" includes, but is not limited to, threaded connections, pin fixation, snap-fit ​​connections, and other methods well known to those skilled in the art.

[0039] In this invention, each gripper unit is independently controlled. Once the sensor detects the target workpiece, it directly triggers the corresponding gripper action, reducing waiting and switching time and improving production cycle time and overall operational efficiency. The gripper heads in this invention feature a detachable design, facilitating quick replacement for new products. The modular gripper unit design also ensures that maintenance or replacement of a single unit does not affect the normal operation of other units, reducing maintenance costs and time. Compared to configuring multiple dedicated devices or complex gripper changing systems, this invention achieves flexible gripping functionality through simple mechanical and electrical integration, resulting in lower manufacturing and maintenance costs and a high cost-performance ratio.

[0040] The above description is merely an embodiment of this utility model and does not limit the patent scope of this utility model. Any equivalent structural or procedural transformations made based on the description and drawings of this utility model, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this utility model.

Claims

1. A flexible gripping device with a multi-claw assembly, characterized in that, include: A connecting plate (1) is provided with an installation interface (11) for connecting to the end flange of an industrial robot. At least two gripper units are fixedly mounted on the same mounting surface of the connecting plate (1); At least two position sensors are fixedly mounted on the connecting plate (1) and correspond to the positions of each of the gripper units respectively; Each of the gripper units includes a drive cylinder and a gripping assembly directly driven by the drive cylinder. Each of the position sensors is connected to the corresponding drive cylinder signal, and is used to independently trigger the corresponding gripper unit to perform a gripping action based on the detected workpiece position information.

2. The flexible gripping device with a multi-claw assembly according to claim 1, characterized in that, At least two gripper units are arranged linearly along the length or width of the connecting plate (1).

3. A flexible gripping device with a multi-claw assembly according to claim 1 or 2, characterized in that, The clamping assembly includes a connecting arm connected to the piston rod of the drive cylinder, and a gripper head detachably mounted to the end of the connecting arm.

4. A flexible gripping device with a multi-claw assembly according to claim 1 or 2, characterized in that, It also includes a sensor bracket (6), through which the position sensor is fixedly mounted on the side of the connecting plate (1).

5. The flexible gripping device with a multi-claw assembly according to claim 4, characterized in that, The sensor bracket (6) is an L-shaped sheet metal part.

6. The flexible gripping device with a multi-claw assembly according to claim 1, characterized in that, The position sensor is one of a photoelectric sensor, a proximity switch, or a fiber optic sensor.

7. The flexible gripping device with a multi-claw assembly according to claim 1, characterized in that, The connecting plate (1) has a weight reduction hole (12).

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