Adaptive angle positioning tool for robot screw tightening

Abstract

The utility model relates to screw tightening technical field especially relates to a kind of self-adapting angle positioning tool for robot screw tightening, including mounting disc, sliding frame, second motor, rotating frame, third motor, horizontal movement component and buffer component, horizontal movement component is provided on mounting disc, sliding frame is assembled on horizontal movement component, buffer component is installed on sliding frame, second motor is fixedly installed on the buffer component, rotating frame is connected on second motor output shaft, third motor is installed on rotating frame.The device is driven rotating frame by second motor to realize front and back inclination angle adjustment, third motor drives rotating shaft to realize left and right inclination angle adjustment, both collaborative work, give the posture adjustment ability of multiple degrees of freedom in space to tightening machine.The function can effectively compensate the pose deviation of screw hole, so that the tightening machine operating port can be quickly and accurately connected with screw cap, significantly improve the adaptability and tightening success rate under complex working conditions.

Description

Technical Field

[0001] This utility model relates to the field of screw tightening technology, and in particular to an adaptive angle positioning fixture for robot screw tightening. Background Technology

[0002] In modern industrial automation assembly, particularly in the automotive, electronics, and aerospace industries, the use of robots for automated screw tightening has become a key technology for improving production efficiency and product quality stability. Traditional robotic tightening operations typically rely on high-precision, high-rigidity robotic arms and pre-taught trajectory programs. This approach places extremely high demands on the absolute positioning accuracy of the robot body, the consistency of the workpiece, and the repeatability of the fixture.

[0003] However, in actual production environments, various factors can cause deviations between the actual position of the screw hole and the theoretical model: these include manufacturing tolerances, fixture wear or positioning errors, and cumulative errors in multi-layer assemblies. In work scenarios with complex curved surfaces or narrow spaces, the tool at the end of the robotic arm struggles to maintain an ideal orthogonal orientation with the screw hole. Traditional rigid tightening tools cannot adapt to such angular deviations, easily leading to stripped screws, worn bits, or even damage to the workpiece, severely limiting the application scope and reliability of automated production.

[0004] To overcome the aforementioned problems, the industry generally adopts two approaches: one is to use expensive high-precision robots and vision systems, which is not economically viable; the other is to use simple floating tightening shaft heads, which can compensate for a small amount of radial deviation, but cannot actively adjust the angle and posture, thus limiting their applicability. In addition, although some existing solutions have introduced visual positioning, their vision systems are usually separate from the actuators or only provide coarse two-dimensional position guidance, still requiring the robotic arm to perform a large number of complex spatial pose adjustments, resulting in low overall response efficiency and making it difficult to achieve true "hand-eye coordination" for real-time and precise pose alignment.

[0005] Therefore, there is an urgent need for a tightening fixture that is integrated into the end of a robotic arm, can actively and adaptively adjust its angle, and can perform real-time high-precision positioning based on visual feedback, in order to make up for the shortcomings of existing technologies. Utility Model Content

[0006] To overcome the shortcomings mentioned in the background art, this utility model provides an adaptive angle positioning fixture for robot screw tightening.

[0007] An adaptive angle positioning fixture for robot screw tightening includes a mounting plate, a sliding frame, a second motor, a rotating frame, a third motor, a rotating shaft, a tightening machine, a fixed frame, a camera, a controller, a lateral movement component, and a buffer component. The mounting plate is equipped with the lateral movement component, the sliding frame is mounted on the lateral movement component, and a buffer component is mounted on the sliding frame. The second motor is fixedly mounted on the buffer component. The output shaft of the second motor is connected to the rotating frame, the third motor is mounted on the rotating frame, and the output shaft of the third motor is connected to the rotating shaft. The rear end of the rotating shaft is rotatably connected to the rotating frame, and the tightening machine is fixedly connected to the center of the rotating shaft. A fixed frame is fixedly connected to the rear side of the sliding frame. The left side of the fixed frame has a through-mounting position, on which a camera is mounted. The controller is mounted on the left side of the fixed frame, and the tightening machine, the second motor, the third motor, and the camera are all electrically connected to the controller.

[0008] To further explain, the outer surface of the camera lens is covered with a transparent, scratch-resistant protective lens.

[0009] To further explain, the operating port of the tightening machine is made of high-strength alloy steel, and its surface has been nitrided.

[0010] To further explain, the lateral movement component includes a support frame, a first motor, and a screw. The support frame is installed on the left side of the mounting plate. The first motor is installed inside the support frame on the left side. The screw is connected to the output shaft of the first motor. The right end of the screw is rotatably connected to the left side of the mounting plate through a bearing. The sliding frame is threadedly connected to the screw and is laterally slidably connected to the outside of the support frame. The first motor is electrically connected to the controller.

[0011] To further explain, the buffer assembly includes a guide rail, a sliding block, and a spring. The guide rail is fixedly connected to the left side of the sliding frame. The sliding block is slidably connected inside the guide rail via two support rods. Two springs are connected between the sliding block and the inside of the guide rail. The springs are fitted onto the outside of the support rods. The second motor is embedded inside the sliding block.

[0012] To further clarify, the spring is a helical compression spring made of stainless steel.

[0013] The beneficial effects of this utility model are as follows: 1. This device uses a second motor to drive the rotating frame to achieve front-to-back tilt angle adjustment, and a third motor to drive the rotating shaft to achieve left-to-right tilt angle adjustment. The two work together to give the tightening machine a multi-degree-of-freedom posture adjustment capability in space. This function can effectively compensate for the positional deviation of the screw hole, enabling the tightening machine's operating port to quickly and accurately align with the screw and nut, significantly improving its adaptability and tightening success rate under complex working conditions.

[0014] 2. By integrating a downward-facing camera, the device can acquire real-time image information of the screw to be tightened. Based on the visual feedback data, the controller accurately calculates the actual spatial coordinates and tilt angle of the screw, and controls the operation of each motor in a closed loop, thereby achieving precise positioning and orientation of the tightening machine end relative to the screw. This visual servo system reduces the dependence on external absolute positioning accuracy and improves the intelligence and operational precision of the entire tightening system.

[0015] 3. The buffer assembly, through the combination of springs and sliding blocks, provides the tightening machine with axial elastic floating space. When misalignment occurs or abnormal resistance is encountered, this mechanism allows the tightening machine to retract, avoiding rigid impact. This effectively prevents damage to the tightening machine, stripping of screws, or shearing, improving the safety and reliability of the operation process, while also providing physical signals for abnormal system diagnosis. Attached Figure Description

[0016] Figure 1 This is a three-dimensional structural diagram of the present invention.

[0017] Figure 2 This is a cross-sectional view of the support frame and sliding frame components of this utility model.

[0018] Figure 3 This is a three-dimensional structural diagram of the guide rail, sliding block, and second motor of this utility model.

[0019] Figure 4 This is a three-dimensional structural diagram of the components of this utility model, including the mounting bracket, camera, and controller.

[0020] The markings in the attached diagram are as follows: 1: mounting plate, 2: support frame, 3: first motor, 4: screw, 5: sliding frame, 6: guide rail, 7: sliding block, 71: second motor, 8: spring, 9: rotating frame, 10: third motor, 11: rotating shaft, 12: tightening machine, 13: fixing frame, 14: camera, 15: controller. Detailed Implementation

[0021] Example: An adaptive angle positioning fixture for robot screw tightening, such as... Figures 1-4As shown, the device includes a mounting plate 1, a sliding frame 5, a second motor 71, a rotating frame 9, a third motor 10, a rotating shaft 11, a tightening machine 12, a fixing frame 13, a camera 14, a controller 15, a lateral movement assembly, and a buffer assembly. The mounting plate 1 serves as the mounting base for the entire device, connecting to the end effector of the robotic arm to achieve overall support and positioning. A lateral movement assembly is mounted on the mounting plate 1. The sliding frame 5 is mounted on the lateral movement assembly and can move laterally. A buffer assembly is mounted on the sliding frame 5. The second motor 71 is bolted to the mounting plate 1. On the buffer assembly, a rotating frame 9 is connected to the output shaft of the second motor 71 to drive the rotating frame 9 to achieve tilt angle adjustment in the front-to-back direction. A third motor 10 is bolted to the rotating frame 9, and a rotating shaft 11 is connected to the output shaft of the third motor 10. The rear end of the rotating shaft 11 is rotatably connected to the rotating frame 9. A tightening machine 12 is detachably connected to the center of the rotating shaft 11, so that the tightening machine 12 can be tilted in the left-to-right direction with the rotating shaft 11. The operating port of the tightening machine 12 is designed to match the geometry of the screw and nut to achieve screw fitting. In addition to the tightening operation, the internal drive motor can drive the operating port to perform the rotary tightening action. The operating port of the tightening machine 12 is made of high-strength alloy steel, and its surface is nitrided, which can significantly improve the hardness, wear resistance and fatigue strength of the operating port, and extend its service life in frequent tightening operations. The sliding frame 5 is bolted to the rear side of the fixing frame 5 and has a vertically penetrating mounting position on the left side. The mounting position is bolted to the camera 14, and the optical axis of the camera 14 faces downwards. It is used to collect images of the screw to be tightened in real time to identify its position and posture information. The outer surface of the lens of the camera 14 is covered with a transparent anti-scratch protective lens, which can effectively prevent the lens of the camera 14 from being scratched by flying debris or accidental contact during operation, and ensure the clarity and stability of the image acquisition quality. The left side of the fixing frame 13 is bolted to the controller 15. The tightening machine 12, the second motor 71, the third motor 10 and the camera 14 are all electrically connected to the controller 15. The controller 15 is also connected to an external monitoring system to realize remote monitoring and control functions.

[0022] like Figure 2As shown, the lateral movement assembly includes a support frame 2, a first motor 3, and a screw 4. The support frame 2 is mounted on the left side of the mounting plate 1. The first motor 3 is bolted inside the support frame 2 on the left side. The screw 4 is connected to the output shaft of the first motor 3. The right end of the screw 4 is rotatably connected to the left side of the mounting plate 1 via a bearing. The sliding frame 5 is threadedly connected to the screw 4 and is laterally slidably connected to the outside of the support frame 2. Two guide rods are welded to the left side of the mounting plate 1. The sliding frame 5 slides along the guide rods to enhance the guidance and stability of the movement. The first motor 3 is electrically connected to the controller 15. By controlling the forward and reverse rotation of the first motor 3, the screw 4 is driven to rotate, thereby driving the sliding frame 5 and its overall structure to move precisely laterally, realizing the fine-tuning and positioning of the tightening machine 12 in the lateral direction. The robotic arm is responsible for the coarse positioning of the execution device in a large space.

[0023] like Figure 3 As shown, the buffer assembly includes a guide rail 6, a sliding block 7, and springs 8. The guide rail 6 is fixedly connected to the left side of the sliding frame 5. The sliding block 7 is slidably connected inside the guide rail 6 via two support rods. Two springs 8 are connected between the sliding block 7 and the inside of the guide rail 6. The springs 8 are fitted onto the outside of the support rods. The springs 8 are helical compression springs made of stainless steel, ensuring the corrosion resistance and stable mechanical properties of the springs 8 in industrial environments, preventing the reliability of the buffering effect from being affected by rust, and ensuring the consistency and accuracy of the buffering force during long-term use of the device. The second motor 71 is embedded inside the sliding block 7. When the operating port of the tightening machine 12 is not fully engaged with the screw and nut and the tightening action is accidentally started, the abnormal tightening force generated will push the sliding block 7 to slide vertically along the support rod. The springs 8 are compressed and deformed to absorb the impact energy and provide elastic buffering, causing the tightening machine 12 to retract and shift accordingly, thereby avoiding rigid collision with the screw and protecting the device from damage.

[0024] When this device is needed, the mounting plate 1 is first installed on the robotic arm. The robotic arm then adjusts the overall position of the device to bring it close to the area where the screw to be tightened is located. Subsequently, the controller 15 starts the first motor 3 to drive the screw 4 to rotate, causing the sliding frame 5 to slide laterally along the guide rod on the support frame 2 and the mounting plate 1, thereby achieving precise adjustment of the lateral position of the tightening machine 12. At the same time, the camera 14 continuously captures images of the screw and transmits them to the controller 15. The controller 15 calculates the actual position and tilt angle of the screw based on the image information and controls the second motor 71 to drive... The rotating frame 9 is used to adjust the tilt angle in the front and rear directions, and the third motor 10 drives the rotating shaft 11 to adjust the tilt angle in the left and right directions, so that the operating port of the tightening machine 12 is accurately aligned with the screw and nut. During the tightening process, if there is a misalignment or abnormal resistance, the sliding block 7 in the buffer assembly will slide along the support rod in the guide rail 6 to compress the spring 8, so that the tightening machine 12 can elastically release and avoid rigid impact damage to the device. Finally, the tightening machine 12 rotates the operating port under the drive of the motor to complete the screw tightening, and then all components are reset to prepare for the next operation.

Claims

1. A robot screw tightening adaptive angle positioning tool, characterized by: The system includes a mounting plate (1), a sliding frame (5), a second motor (71), a rotating frame (9), a third motor (10), a rotating shaft (11), a tightening machine (12), a fixing frame (13), a camera (14), a controller (15), a lateral movement assembly, and a buffer assembly. The mounting plate (1) is equipped with a lateral movement assembly, the sliding frame (5) is mounted on the lateral movement assembly, and a buffer assembly is installed on the sliding frame (5). The second motor (71) is fixedly installed on the buffer assembly, and the rotating frame (9) is connected to the output shaft of the second motor (71). The third motor is installed on the rotating frame (9). (10) A rotating shaft (11) is connected to the output shaft of the third motor (10). The rear end of the rotating shaft (11) is rotatably connected to the rotating frame (9). A tightening machine (12) is fixedly connected to the center of the rotating shaft (11). A fixed frame (13) is fixedly connected to the rear side of the sliding frame (5). A vertically penetrating mounting position is provided on the left side of the fixed frame (13). A camera (14) is installed on the mounting position. A controller (15) is installed on the left side of the fixed frame (13). The tightening machine (12), the second motor (71), the third motor (10), and the camera (14) are all electrically connected to the controller (15).

2. The adaptive angle positioning fixture for robot screw tightening according to claim 1, characterized in that: The outer surface of the lens of the camera (14) is covered with a transparent scratch-resistant protective lens.

3. The adaptive angle positioning fixture for robot screw tightening according to claim 2, characterized in that: The operating port of the tightening machine (12) is made of high-strength alloy steel and its surface is nitrided.

4. The adaptive angle positioning fixture for robot screw tightening according to claim 3, characterized in that: The lateral movement assembly includes a support frame (2), a first motor (3) and a screw (4). The support frame (2) is installed on the left side of the mounting plate (1). The first motor (3) is installed on the left side inside the support frame (2). The screw (4) is connected to the output shaft of the first motor (3). The right end of the screw (4) is rotatably connected to the left side of the mounting plate (1) through a bearing. The sliding frame (5) is threadedly connected to the screw (4) and is laterally slidably connected to the outside of the support frame (2). The first motor (3) is electrically connected to the controller (15).

5. The adaptive angle positioning fixture for robot screw tightening according to claim 4, characterized in that: The buffer assembly includes a guide rail (6), a sliding block (7), and a spring (8). The guide rail (6) is fixedly connected to the left side of the sliding frame (5). The sliding block (7) is slidably connected inside the guide rail (6) through two support rods. Two springs (8) are connected between the sliding block (7) and the inside of the guide rail (6). The springs (8) are fitted outside the support rods. The second motor (71) is embedded inside the sliding block (7).

6. The adaptive angle positioning fixture for robot screw tightening according to claim 5, characterized in that: Spring (8) is a helical compression spring made of stainless steel.

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